. RADIOCIiEMIStRY DIVISION ANNUAL PROGRESS REPORT FOR 1971
Edited by
BHABHA ATOMIC RESEARCH CENTRE
<
Edited by
BHABHA ATOMIC RESEARCH CENTRE BOMBAY, INDIA
1972
I H T R O D U C T I O
The major highlights of the activities of the Hadiochemistry Division during the year 1971 were research and development work on the actinides and other radioelements and services like chemical, mass speetro- metric, x-ray and optical spectrographio analysis of plutonium and other radioactive materials and supply of special radioactive sources to various institutions inside and outside BAEC. As in previous years, research on the actinide elements centered around solution and radiation chemistry of Plutonium, study of various complexes using x-rayf e.p.r. therraograviraetrio, Mossbauer and optical spectrographie techniques and investigations of neutron induced fission. The development work on actinides included process chemistry of neptunium, preliminary studies on transpluton* ;«>. elements, setting v.p and operation of gamma-ray and neutron monitoring assemblies SOB the in-line analysis of fission products and plutoniuim respectively in Ssel reprocessing streams and the accurate analysis of plutonium in plutonius oxide samples and sintered FUO? pellets* In the chemical development worie on molten sal t breeder reactor ooncept utilizing plutonium, the solubility of Plutonium trifluoride was determined in the ternary system and the binary system
C O N T E N T S
introduction
1.1 Sol-rant Extraction Studies
1.1.2 Extraction of some txivalent lanthanides from
thiocyamte by neutral organophOBphoroas extraotanfe* ft
1.1.3 Studies on the oomplexes of lantbanidea 12
111.4 Investigations on the chemistry of Pa(YIl) W
1.2 Studies in Radiation Chemistsy
1.2.1 Gamma radiolysis of plutonitto( lI l ) / ( lT) syatea In 0 .8 N, 6 H and S N hydrochloric acid solutions t@
1.2.2 Ganma radiolys is of plutonlum(ll l ) i n adtric aoid solutions 25
1.2.3 EPR stadia8 of intermediates fcaned in xadiolytio and redcoc reactions in aqueous medium 29
1.2.4 Badlation chemistry of nitrio acid JO
1.2.5 Two phase radiolyaie and the e f fec t of radiatiou on ffa* . diBtxihution coef f ic ient of uraniwa and piatoniua 36
1.2*6 Slaeh photolysis of sulphanllanld* and ether p-suhstituted a n i l i n e s 39
SECTION 2 t STHtrCTORAL STUDIES
2*1 Solid Complexes o f Uranyl 0 -diketones with I>ea«r Chain Aliphatic Sulphoxides ' 44
2.2 S tab i l i ty Correlations and Sterio Effects of Synergistia Complexes 45
2*3 X-ray Structural Studies
I l l
2.3.1 Refinement; of the oryetal structure of uranyl oxalate 48
2.3.2 Qralato and aoetato complexes of aotiaides 51
2.5«3 Non-stoiehiometrio oxides of the lanthanides 55
2.3.4 Calibration of Mattler thermoanal^sec »
2*4 Mouebauer Studies
2,4.2 Preparation of 1 4 5Pa g3
2.5 Fluorescence and Absorption Spectrum of Tb*+ Ion
i n laBr, Crystal g^
2.6 Energy-tranafer Studies in Raxe Earth Chelates $$
2.7 BPH Study of TC-"H" i n UOgtHOjJgifiHgG Single Crystal 74
SSCTIQR 5 1 NUCLEAR CHEMISTRY
5*1 Eadiochemical Studies on Fission
3*1.1 Be coil ranges and kinet io energy dis t r ibut ion i n the reactor neutron f iss ion of 23'Hp 80
3.1.2 Becoil ranges of isobar pairs iu tbs thermal neutron fission of ^-*tf &
3 >1 "3 Studies on highly asymmetrlo binary fission t Fission
of natural uranium with reaotor neutxons • Sf
3.2 mission Studies using Solid-state Track Deteotors
3.2*1 Total fLsaion cross section for th» thermal and 14 MeV neutron induced fission of 231 Pa 94
3*2.2 Mass and angular distritution in Mission using
correlated fission track technique 95
3*2*3 Analysis of angular distributioo data a t 15*9 BeT $B
3*2*4 Thermal neutron flux distribution at the thermal> , j 102
3«3 i laaion Studies using ilass Spaotecmgtrie Steebniqa© 106
3*4. - Calibration of a <fe(Li) Detector 106
i T
3*5.1 ELeotrodeposition studies with 244Ca 107
3*5.2 KLeotrodeposition of piotaotiniun 112
3*5*3 Mechanism of electrodeposition of aoSinide* 113
3.6 Computer Programme for Analysis of Oe(ll)
Gamma-ray Spectra 115
4*1 Process Chemistry Oi Feptuniun 117
4*2 I n - l i n e Analysis of Fuel Bsprooarsing Streaas 123
4.2.1 In-line monitoring of f iss ion products 124
4*2*2 Heutrca monitoring for plratocj.um 331
4*3 Iransplatonium Elements 1324.4 ^-ray Huoxesoenoe Analysis of Aotinide Blemeafcs in Solution 136
SECTION 5 t REACTOR CHMISTHY
5.1 Chemical Development Work on Molten Salt Breeder
Beaotor Concept c - ^
5.1*1 Preparation of pure Thl1. and I1F 141
5.1*2 Solubility of PuFj In l ^ ^ F g ^ B ^ m^t«^s 142
5.1 »3 SoluTsilHy of PtiFj in LiF-IMP. nixtux«s 14i5
5.1.4 Impendence of solubi l i ty of PuF, on the sa l t ooapoeition 146
SSCTIOH 6 s AMLTfTlCAt CHEMISTRY iMD MISCELLANEOUS SiSKVICSS
6.1 Mass Speetrometry ISO
6.1.1 Analyt ica l eerricea : 150
Isotope di lut ion method for input accountabil i ty i n a reprocess ire plant 151
Fuel burn-up measurements 152
Determination of " tJ content of Natural and Depleted
Uranium Samples by F i s s ion Track Method 154
Analysis of FuO. f o s Auditing 159
Emission Bpeotzoscopy
Analysis of some common impurities i n high purity selenium 159 New Badiochemical Methods for the Separation of Cu and Heavy Bare Earth Elements from Fi s s ion Products
67
fiadiochemical separation of 'Cu a c t i v i t y 16?
Eadiodhemlcal separation of heavier rare earths 168
Supply of Radioactive Sources I73
Eftdioohemistry Laboratory at the Reactor Research Centre 173
SECTIQH 7 j INSTRUME3ITATI0N
7«2 A Low Geometry Alpha Counter 177
Summary 180
List a£ Publications During 1971 186
L I S T OF T A B L E S
Table 1 »
Table 2 *
Table 3 *
Table 4 *
Table 5 *
Table IB t
Table 19 *
Extraction of La(III), Eu(III), tu(lIX) and Am(lIX) by TOPO, TBPO and TBP
Dissociation constants of Uganda
Stability constants of Sm+5 oomplezes (by least squares)
Ganina radiolysis of plutonium(lll)/(iv) system In 0.8 N HG1 t Yields of plutonium(xv) and ^O
Spectrophotometric measurements on solutions irradiated by gamma ray in the presence of oxygen.
Gamma radiolysis of argon equilibrated plutonium(lV) solutions i Yields of plutonium(lll) and
Hadiolysis of oxygen equilibrated plutoniom( III) solutions in 0.8 H HNO, containing different concentrations of sulpnamio acid
Present G(HNO2) values compared with other published values
Ratio of rate constants —— from thermal studies K1
Decrease in Q(HNOg) with dose
Bate constant -values of the reactions of substituted benzenes and anilines with eaq
Characteristic infrared stretching frequencies (en ) in the complexes UOg(fi dike tone )gS
Boni distances (1) and bond angles (•)
X-ray data
Hossbauer parameters
Hossbauer parametesp of the ferrous and ferric iron
Ferric iron oontent as percentage of total Iron t Comparison of Mossbauer and chemical data
8
14
16
1Q
20
23
24
35
36
38
42
47
49
yy
54
56
60
61
62
v l i Page
Table 20 s Absolute rats constants for quenching of fluorescence from the J?Da le^el of %5+.^p0 * 17,250 ear1. Solvent I Acetone . .
Table 21 » Spin Hamiltonlan constants foe TO44 ion
Table 22 » The recoil ranges and kinetio_energies in the reactor induced f iss ion of 25"ijp
Tettae 23 * Fission yields for reactor neutron induced fission of natural uranium
Table 24 f Anisotropy data for the 15.8 ifeY neutron induced fission of heavy elements
Table 25 * Thermal neutron flux in Apaara thermal column using S.8.T.J laxan
Table 26 t Counting efficiencies of Ga(Li) detector for different nuolides
Table 27 i Counting efficiencies of Ge(Li) detector for different nuclides
Table 28 i Extraction of.Np(v)
Table 29 * Extraction of neptunium
Table JO t Variat ion of S^ with HNO, concentrat ion
able 31 * Variation of K£ with concentration of uranium
Table 32 t Analysis of two compenent mixtures using Nal(Tl) monitoring assembly
Table 33 i Analysis of three oomponest siixtures using Hal(Tl) monitoring assembly'
Table 34 t Energies of alpha particles from various plutonioa isotopes and those of 24iAm ( in MeV)
Table 35 « Solubility of PuPj in lIP-BeF2-ThF4 (71.6, 16.29 12.2 m/o)
Table 36 t Precision in uranium isotope ratio measurement using an.NBS standard sample
Table 37 * Bstemination of total plutonium in ths tank
Table 38 * "tf content of natural uranium and dspletee! uraniam samples
72
77
82
102
104
108
109
119
120
122
122
128
150
135
144
-550
153
156
Battle 39 * U oonient in syntbexio mixtures of mtural + depleted uranium
Table 40 t Precision and accuracy of Hie date
Table 41 1 Equations for the working ourrea for different elements
Sable 42 I Line pairs and estimation range*
157
162
163
164
table 43 * Comparison of detection limits obtaimd by different methods 165
L I 3 T 0 P F I G U R E S
Figure
figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
1
2
3
4
5
6
7
8
9
10
11
12
15
14
15
16
17
16
19
t
t
t
i
e
t
t
t
t
i
s
t
1
t
t
i
i
Plot of log K and log K va pKD of the @ -dHcetone
Plot of log K TS shift in the 8ynaaetrio stretching frequency of water of different donor hydrates
Plot of chemical shift va donor concentsaiis
Plot of chemical shift va log K
Extraction of La( l l l ) , Eu(l l l ) , Lu(ll l) and Ao(XIl) from thiocynmte by TOPO
Absorption spectra of Hd(lll) and Er( l l l )
Formation curve
Badiolysis of deaerated and argon equilibrated Pu(lll) solutions - yields of Pu(l7) and Hg
Badiolyais of oxygenated plutonium( III) solutions yields of plutonium(lT) and
Badiolysis of plutonium(lll) in nitr ic aoid solutions - yields of plutonium(lT) and
Effect of gamma radiation on EER spectrum of 0.05 M PeClj in 0,16 M HOI at 77°K
Test of competition for HHOg species between SA and HgOg in tiie radiolyels of n i tr ic aoid
Test of simple competition for HNO2 specie? . between SA and H2O2 in nitrio acid, SA • 10*4 M
as a function of CgHg
as a function of CgHg
Eelation batweenpK^ ani TT-Q and carbonyl stretching frequencies
Eelation between log k and enthalpy ohange
Uranyl csalate unit ce l l (010) projection
ix
9
10
15
17
21
25
26
JO
33
34
41
41
46
46
50
Figare 33 »
Figure 34 *
Figure 35 *
Figure 36 >
Moeebauer spectra of Chavara ilmenite at (a) room temperature and (b) liquid nitrogen temperature
Mossbauer spectra of Manavalakurichi ilmenite at (a) room temperature and (b) liquid nitrogen temperature
Fluorescence line groups for transitions from 5 to 7
Energy level eohaae shoving the transition between 5ju a n i ?F levels of Tb3+ in
Energy level scheme showing the transitions between 5© a na 7F levels of Tb3+ in LaBr*
Eu(DBM) in acetone (1O"*Z ll)
Eu(MM) in ace tons (1O~2 H)
EPR spectrum of 70 ion in uranyl nitrate hexahydrate single crystal
Plot of the line-width, A H, against mj
Hot of recoil range vs naea number in the fission of 237
Kinetic energy distribution for ^'Np fission using different range-energy equations
Hot for 14°Ba - 1 4 ° l a in catcher A
Plot for 14°Ba - 1 4 °Ia in catcher B
Mass distributions in the fission of 235,
by thermal neutrons and by reaotor neutcona
Yields of low-yield products In the heavy mase region in the f i s s ion of 235n- ty xautrona of different energies
Yields of low-yield products in the heavy mass region in the f i s s ion of 23% by neutrons of different energies
a) Relation between the ranget track length and angle of fiaaion fragments in lexan and (b) Variation of »ange ratios with mass number of f ission fragments $6
59
59
66
67
68
71
71
76
79
83
83
86
86
90
91
92
xi
Figure 37 « Mass and angular distribution in f ission using correlated fiBsion track technique (a) Mass distribution in the thermal neutron fission of 2
Figure 36 t
Figure 56 t
(b) Angular distr ibution in th9 thermal neutron fission of 235u
Thermal neutron flux in Apsara thermal column
Gamma-ray efficiency curve for Ge(ld) deteotor ' Sample diameter 1 .0 cm
Gamma-ray efficiency curve for Ge(Li) detector * Sample diameter 2.5 cm
Electrodeposition of curium
Electrodeposition of protactinium
Gamma-ray spectrum of dissolver solution
Plot of transmission values for f iss ion product gamma rays vs lead absorber thickness using Nal(Tl) detector
Plot of peak area vs source-detector distance for some fission products using a Ge(Li) detector
Recovery of americium from solution containing large amounts of rare earths
Calibration curve for thorium solutions
Calibration curve for uranium solutions
Calibration curve for plutonium (0-400 ug/ml) in presence of uranium (300 og/ml)
Solubility apparatus
Solubility, of PuFj in LiF and ThF4
Volatil isation curves for Pd (3027-9 &)t Te, Hg and As
Working curves for Mo and Mn
Flow diagram for separation of Cu from uranium and f iss ion products
99
103
110
110
112
114
114
125
127
151
135
138
138
139
142
144
147
160
166
168
xii
67Cu ganma spectrum
Flow diagram for the separation of rare earths fron uranium and fission products
177Decay curve of "Lu 172Decay curve of ' Er
Scanning monocbrooator set-up fta? fluorescence studies
Iron spectrum (lind order)
Fluorescence spectrum of europiun dibonsoyl metaide (solid) at 77*K
low geometry alpha oounter assembly
16?
169
171
172
172
174
176
176
178
1.1 Solvent Extraction Studies
Since the discovery of synergism in solvent extract ion by
Baes e t . a l y there have been numerous attempts to explain the mechanism
by whioh syiserglem occurs. From the point of view of understanding the
mechanism of the synergist io extract ion of uranyl ion with Q> -diketones
and neutral donors (sulphoxideB, phosphine oxides, phosphates) in greater
d e t a i l , the e f f e c t of functional groups of the ^ - d i k e t o n e with a given
donor and the e f f e c t of bas ic i ty of the donor with a particular fi> -diketons
on synargism was invest igated. Some other aspects such ae ef fect of temp- (2 l )erature and s a l t concentration on s imilar systems were reported ear l i er .
Effect of functional groups of the ft -diketone
I t was observed that for a particular sulphoxide donor(s), the
chaiiges in the substituents a t the carbon atoms of the & -diketone affected
the synergist ic enhancement only so far as the subst i tuents affected the
a c i d i t y of the ft -diketones. This i s clear from Figure 1, where tLe values
of log K and log E when plotted against pKj, the negative logarithm of the
acid d issoc iat ion constant of the A -diketone gave l i n e a r re lat ionships .
K and K are the equilibrium constants for the overal l synergist ic react ion
and the organic phase reaction respect ive ly and are given by equations 1 and 2«
log K - log (B - Do) + 2 log JTH+«7 ~ 5 lo« /"M-7 " l 0« fSJ "• W
log K' - log K - lor k . . . (2)
where 2 and Do are the distribution coefficients of uranium in the presence and absence of the synevgist and k, tha equilibrium constant for the extraction of uranyl ion with the /£} -diketotis (Hi) and is given hy equation (3)«
r
- 2 -
log k - log D + 2 log £itj - 2 log (3)
• 0090 P biAso A CHSO
Figure 1 i Hot of log K and log *' ve pK of the /3 -dikotone
Th«s« atudiw revaal feat a utanyl ^ -dlk«toj» chalate with thanoyl trifluoroeottone (TTi) or benaoyl trlflaoroaoetom (KWA) b^fing a lowep pKp T«1U« hare th» greatest tvndsnoy to faoilitate tha bonding of th« neutial ligaad to the netal duo to th« def ioisnoy of elsotron density around tb« axaniuK oauatd by tho electronegative eabatituents of the /S-dUcetooe nhioh reanltB in edtanced Bynergism. CoEnrotaeijr, tihen th« jS^ikotOBe such as bea«oylao«ton« (BA) or dibensoylm»thaal (BBK) forai a r&ther strong ehelate w«h uxaninni, the t«ndeuoy for th» binding of tht neutral donoj? i» alight and taoh systenB show less pronounced oynerglam.
- 3 -
base atrength of the donoys (aulDhoocides) - Infrared studies
The infrarad spectra of demos faydxates in CCl. prepared by equilibrating the donor ia CCl. solution with distilled water showed two bands for coordinated water at 3690 and 3640 cm . Of these* only the 364O oa tend wan found to shift in wave length with different donor* 0 The band at 300 ca" f {bough of higher optical density was found to be
to the donor strength. 1 plot of log X (TTA and 3TF&) va in the aymuetrlo stretohlng frequency of water fron%640 ca"
(Wgare 2) gare a straight line lndloating that the stabilities of the ooxplexes «ith different donors axe proportional to their basicities.
4-0,
SEE
SBM4SUtPH0XIDE B* * !>UL»HOXIDC
HTTA+SULf'HOaiDt BTfA-t S
Figure 2 * a p t of log &' VB shift in the synsratric stretching of water of different donor hydrates»
-4 -
Wuolear Magnetic resonanoq studies of the hydrates of tha donors (snlThoxldea. phogphine oxides and phosphates^
The mclear aagnetio resonanoe speotra of donor hjdratea in varying
concentrations in CC1. indicated that the waller protons were shielded to
the extent of about 2 ppai from ordinary nates. A plot of the chemical ehift
of the water pzotons (o/s from TMS) in the donor hydrate r* the donor
concentration in CC1. la giren in Figure 5*
200
Figure 5 » Plot of chemieal shift ra donor concentration.
Ihe shifts seem to reach a aaturation value at 2 H donor oonoentration A plot of the chemical shift (o/a froo TMS) of the water protoss In
-5 -
donor hydrate at 2 M concentration YB the log K ' i s given in Figure 4
for the ays tens with HITA (BIFA) and the donors (sulphoxide).. Tae shift M
proportional to ths base strength of the neutral donor, the largest shift
being observed with the BOB* baaic txlootylphoaphins oxide and the
with the weakly basis diphenyl eulphoxide.
ISO
Figure 4 » Hat of chemical shift va log K
1. C.¥. Baee, C.A. Elate, E.B. Brown, C.F* Coleman and J.C.
Proo. Second Int. Conf. on the Peaceful Uses of Atomic
W 1058, 15/|/I55O.
- 6 -
2 . M.S. Subxananian and Mrs. S.A* Pai, Bad. Chera* Divn* Ann* Report
for 1969» BABC/I-79, p. 29 (1970).
5. U.S. Subramaidan and Mrs. S.I. Pai, Bad. Chem* Dim. Aim. Report for 1970, BARC/l-135, p. 9 (1971).
1.1.2 Extraction of acne trivalent lanthanides from tfaiooyanate by neutral or.sar.ophOBphQrOHS extraotants
P.K. Khopkar and P. Narayararikutty
Studies on the extraction of trivalent lanthanides and actinides
from thiocyanate solutions is of interest in oonneotion with the develop*
nent of separation methods for the Isolation of transplutonioa elements.
Extraction of these metal ions frost nitrate media by organophosphoroas
extractants was studied extensively by Peppard et.al^1* and Best e t .
and i t was shown that the extracted species was the trisolvated complex
like M(HO,),. JTBP. Studies on the extraction from thiooyamte solutions
has not been as extensive as with nitrate solutions* The present work deal>
with the extraction of i a ( l l l ) and l u ( l l l ) from thiooyanate solutions by
three neutral organophosphorous extractants, namely tri-n-octyl phosphino
exide (TOPO), tri-n-bu^rl phosphine oxide (TBPO) an*tri-n*hutyl phosphate
(TBP). In addition* absorption spectra of Hd(lll) and B r ( i ^ . extracted
these extractants from thiocyanate solutions were studied in order to get
information about the coordination number of the netal ions i n the organio
phase*
The tracers 1^°ta and " l a were used to study the extraction of
La( l l l ) and I o ( i n ) respectively. Hadioassay of the tracers in both phases
was made by Y-oounting using a well type Nal(Tl) detector asaembly. "Free11
extraotant concentrations were calculated from the equilibrium constants
for the uptake of thiocyanio aoid by these reagents and from the measured
equilibrium pH values of the aqueous phase. The complexes Nd(SCH),.4TOPO aafl
Br(SGH)j.3TOPO were prepared and their composition was determined by the
analysis of the compounds for metals, antony carbon and hydrogen. The two
compounds were dissolved in xylene and their absorption spectra taken.
- 7 -
Bstxaotion of neutral solvated species of the aatal iona fron
solutions by ths extxaotants is represented by equation (t)
The equilibrium constant K for Vm above reaetion eaa ba traittsn as In equation (2)
that the activity coefficients of th» Bpsoies involved axe assuned to xeaain ooostant over tiw ranges of concentratione used. If B, the distsi- bntion oeeffiolent of the metal ions is defined as given in equation (3)
. . . (3)
• o
Bj eto.. being the overall stability constants of the metal iona vith thiooyanate £©ns» Taking logarithms on hoih aides of equation (4) raarranging, equation (5) is obtained.
legD . leg1^ + 3 l o g i w T J + X log
Plots of log JD TS log /"SjEO.7 •noold g i w straight Unas
with slopes equal to T.v when thioojranate Ion ooheentration in tba aqueous
phase i s aaintained constant. Figure (5) gives snob plots for l a ( l l l ) and
l a ( l l l ) when TOFO was use A as fee aottrabtant. i l so ineluded in the figure
axs data for l a ( n i ) anft Jm(lll) obtained earlier^5 ' . Ths haloes of X and
S ' fox theaetal ions wlita three extracteats are given in 3*ble 1.
TABLE 1
Extraction of La(lll), Eu(lll), lu(lll) and Aa(lll) by TOPO, TBPO and XBP
Sctraotant Ion Solvation
.3+
4
4
4
3
4
4
3
7.78
9.32
9.81
9.04
-0.38
0.11
0.67
0.44
- 9
5 « attraction of l a ( l l l ) , B i ( l l l ) , Iu(ll l) and Jta(lli) from thio-oyanate by TOPO
Attraction of lanthanidse aad im(lIX) fxon thioojranate by TOPO la well as the values of X and K for these metal ions given in Table 1 axe froa data obtained earlier^5 . It is seen frcm the data in 5kbl« 1 that «baa
es
ooapl«c*8 with the earn colvation nnmbsrs are oonsidared, «i« Taluea of ^ for a given aetal ion Increase In the order of Inoraasing basicity of axtzmotants and inoraaaa with decreasing Ionia xadii of the natal iora thus indicating the inner oomplex chazaeter of the extracted species. She solTatic nuabera of the »etal ions ( i . e . the nanber of extraotant molecules associated with th« natal ions in tee organio phaaa) deoreaaef in general fxoie 4 for the lighter lantbanldes to 3 for the hearier onos vitii an exception in oasa of the extraction of £a(l l l ) by ^P where i t 1B aqual to 5* This deoraaaa 1M tha, ael^ation number of the lanthenides is psobably Sma to dcoreasa ia eoora&s&tlon, naabss of the lanthanides in th® extsaetel
- 10 -
IHMUM(B)
Cal
NIOOYUilMMU
8100 •090
ty TOPO b) ftctzaotion txom ISilocyanaXt Try
TOTO, oscillator strength - 22.6 x 10"^
o) Id(SCl)5.4TOPO osoUUtor •t»ngth » 21.3 x 10"6
a) Er(lll) eitrsOted froa O
b) Ertraotion fron thlooyaxutt« by TOPO, oscillator atxexvgrtli -
o) Er(SCH)3.3TOPO ©soillator
- 11 -
assuming that water molecules are not accompanying the metal ions In the
organic phase* In order to examine this problem furthert absorption spectra
of Hd(ni-) and Er(lll) representatives of the lighter and heavier
lanthanides respectively extraoted by the three extraotants in xylene from
thiocyamte solution in the region of their "hypersensitive" bands were
examined* The shapes of these bands were correlated with the coordination
number of 12M metal ions in some complexes as well as in aqueous solutions
by
Figure 6 shows the absorption speotxa of Hd(lll) and Er(lll) extracted
by TOPO la xylene from thiocyanate solutions. The shapes of the absorption
bands of these lanthanideB extracted by TIP and TBPQ were found to be
identical to those of the lanthani&es extracted by TOPO. Absorption spectra
Of the complexes Hd(SCN) .4TOPO and Br(SCK),. 3TOPO in dried xylens as also
those of Nd(lll) and Er(lll) extracted by TOPO from nitrate solution axe
included in the figure for comparison. The shapes and osoillator strengths
of the absorption bands of Nd(lll) and Er(lll) extraoted by TOPO from
thlocyanate agree well with those of the complexes Hd(SCN),.4TOP0 and
Er(SCH),.3T0PO. The shape of the absorption band of Hd(lII) extracted from
nitrate is significantly different from the other two Nd(lll) spectra
probably because Nd(lll) is 6-ooordinate in the nitrate complex^ . 3ae
agreement of the shapes and the oscillator strengths of the spectra of the
lanthanides extracted from thioeyanate solutions with those of the isolated
complexes tends to suggest that the coordination number of the lanthanideB
are tha same in both their solid complexes and in t&eir extracted complexes,
and the decrease in solvation numbers observed in the tracer experiments
is a direct result of the decrease in the coordination numbsrs of the
lanthanides extracted into the organic phase with decrease in their ionio
radii.
References
1* B.F. Peppard, J.E. Earls, P.Ro Gray and G»ffo I%son« J« Phys.
57t 294 (1955).
2. ,C.P» Best, Eo Hssfosds and H.A«C. McKay, J. Inorg» Uuolc
iaf 136 (1959).
- 12 -
P.K. Khopkar and P. HarayatB.nkw.tty, Bad* Chem. Dim. Ann. Report for
1970 BABC/I-79. P.I (1971)«
1*1.3 Stadias on the complexes of lanthanidea
O.M. Hair, H»P. Singh, Keshav Chandler and J.K. Joahi
The studies of the complexes of lanthanides carried out comprise
the determination of the coordination cumbers of some complexes with TOPO
«nd TBPO and the s tabi l i ty oonstants of some Sm(lll) complexes. The interest
In fee former work arises from tine studies carried out in this laboratory
on the extraction of some lanthanidea by TBPt TOPO and TBPO from aqueous
solutions^ . The object of the present work i s to prepare in pars foist
the complexes of the lonthanides with TOPO and TBPO and to determine their
structure. Since Sm(lll) i s the laathanlde analogue of P u ( l l l ) . work on the
determination of the s tabi l i ty constants of Sm(lll) complexes was started
with a view to extending i t to Pu(ll l) complexes. Study of Fu(XIl) complexes
is of interest since Plutonium forms a variety of complexes with a number
of organic Uganda in different oxidation states , some of which are formed
during the separation and purification of plutonium in the fuel reprocess-
ing eyole.
The TOPO and TBPO complexes of lanthanides
The TOPO and TBPO complexes of l a , Pr, Nd, Sm, Gd, Dy and Er in
nitrate, chloride and thiocyanate fora were prepared by extracting the
corresponding salt into a benzene solution of the ligand* The solvent was
evaporated off and the complexes were dried in a vacuum desiccator over
s i l i c a gal* Proa chemical analysis the composition of the complexes was
found to be KXj.3TOFO(3TBFO) (where X stands for nitrate, chloride or
thiocyanate).
The.infrared spectra of the complexes were taken using a Perkin- ELiaer~237 infrared spectrometer* The TOPO complexes, being viscous liquids
- 15 -
at room temperature t were used as such for IR measurements. The TBPO
oomplexes being sol ids , were used in the form of solutions in GC1.. 4
calls were used for a l l measurements. From the infrared spectra the ohloride complexes of TOPO except for the Er complex were found to contain water molecules. The number of water molecules present was found to he one by Karl-Fiflcher t i tration. A strong hand at 1270-1J00 ca in the nitrate complexes indicates the presence of hidentate nitrate groups in the complexes. A hand at 2040-2070 cm*" in the tbiooyanate complexes corresponds to the iaofchloeyamte structure for *ho complexes (if-HCS) where the nitrogen
( 2)instead of the eulphur acts as the donor atom* •
A Mettler Hiermoamlyaar was used for the the rmogravimetrie studies
of nitrate and thiocyanato complexes of Nd, Gd and Dy* 2ke metals chosen
were representatives of the lighter* middle and heavier lanthanides. No
. chloride complex was studied because of the fear of corrosion of the
instrument. Nearly 10 mg of the complex was heated to 1000°C at the rate
of 6*C per minute in dry atmosphere for the thermogravixnetric studies. All
the oomplexes studied were found to lose the anionic part (nitrate or
thiooyanate) a t around 350*0 which was confirmed by the infra red spectra
of heated products. She major weight loss was observed at a*;out 700°C
when tiie organio matter was oxidised. The final residue l e f t after heating
to 1000*0 was found to have the netaphosphate composition from the weights
and from -the infrared spectra of the final products. Thermogravlmetrio
results indicate that the ligands TOPO and TBPO form stronger bonds with
the metal ions compared to the anions nitrate and thiooyanate.
From the infrared spectra, at least one of the nitrate groups in
the nitrate complexes seems to be bidentata. Therefore the nitrate oomplexes
should be expected to have a coordination number of seven* eight or nine
depending on the number of NO, groupB acting as bidentata. 3he absorption
spectra of the TOPO axtd TBPO complexes of the chlorides* thiocyarates and
nitrates of the lsnthanides were taken and i t was observed that the shape
of the hypersensitive bands was similar in the case of the chlorides and
thiooyanates while i t was different in 13i9 case of the nitrates. Therefore
i t can be assumed that the nitrate complexes are e i t h e r eight coordinate ©r
nine coordinate • The chloride and thiooyamte oomplexes trare found to be s i s
- 14 -
coordinate froa their composition except the hydrated complexes of chlorides with TOPO which should have a coordination number of seven as men fion
their composition. Experiments axe planned to take the far infrared spectra of these complexes in order to confirm the above conclusions*
The stability, constants of complexes of fo
The s tabi l i ty oonstants of the complexes of sanariun(lll) with formio
aoid, acetic aoid and sulphosalioylio acid were determined by the Bjerrun-
Calvin pH titration technique" . The medium chosen for the study was 1 1
HaClO. at 25'C. A Beokman Research Model pH mater was used for a l l pH
meaaurements* I t was standardised with NBS standard buffers and was
calibrated for the measurement of hydrogen ion concentration from the pH
reading in the range of 2 to 12 pH. The ionisatioa constant of water was
determined in 1 II HaClO at 25'C following the method of Libert! and Li
and a value of 1.89 x 10" 4 was obtained* The dissociation constants of
formic acid* acetic aJid, propionic aoid, n-butyric acid, iso-butyrie aoid,
benzoio aoid, salioylio aoid and sulpbosalioylie aoid were determined by
titrating a known a m o u n t of the compound against 0*1 M carbonate free
HaCH ia 0eQ H waClO.. The results obtained are given in Table 2 . 4
TABES 2
1 Formic aoid . 3*00 x to"1*
2 Acetic aoid 2.54 X 10~5 -
3 Proplonio aoid 1.95 x i o " 5 , 4 H-butyric acid 2.16 x 10*"5 -
5 I«o«butyrio acid 2.02 x 10"5 -..-... . . . " 6 enJBOioacid 9.24 x 1Q~5 -- / .
T Salioyild-aeid 1,47 x 10"? . 1 .(6^.^ 1(f t 5 •'.''..
8 Saiphoaalicylic a d d - 5«ii» x 1CTJ '2,
- 1 5 -
the disaooiatlon constants of the Uganda are squired for ttae calculation of the stability constants by the Bjerssn's method*5*. For the stability constant determination of the complexes a mixture of the natal ion and lieind in different rat io waa titrated with 0.1 H HaOe. the pH reading vea taken after each addition of an aliquot of the titrant t i l l the system tooaae opaleaoent due to the precipitation of the metal ion an i ts complex or as a hydrolysed speoies. Ohe fornation fuaetion n (ratio of the concen- tration of ligand bound to aetal to the!total metal concentration) TO8
ealoulated for each polnt*5\ ^r plotting n against pA (pA - -log A _ A ia the equilibrium llgand ion ooneenttation) the formation curve for the oonpleiee m i obtained. One typical formation curve ia ahom in figure 7*
Ic 02
- 16 -
from the Tallies of the formation function the stability constants were calculated boih by graphical analysis and by least squares calculations**'. The results obtains* by least squares calculations axe given in liable J»
TABL5 3
Stability constants
Formlo aoid
Acetic aoid
103
1012
In order to- correct for any hydrolysis effect on the s tabi l i ty
constants of complexes of Sm(ll l ) , the hydrolysis constants of th i s ion
wera determinad. A known a m o u n t of samarium An 1 M BaClO. was
titrated with 0.01 M MaOa in ths same medium. Titration was continued t i l l
the metal hydroxide got precipitated from the system. From the pH reading
after each addition of the titrant the value of xl (n. - concentration of hydrogen ion fron hydrolysis per Unit concentration of the metal ion) was calculated and was plotted against tha corresponding pH. From Figure 8 i t i s dear that the hydrolysis curve is independent of the metal ion concen- tration indicating the absence of poly-nuclear species in the system* From the graphical analysis of the data using equation ( i )
- 17 -
• 0-023M • « • *
e t Plot of n. VB pH
til* hjrdrolysi* oomter.ts for the f l w t two species, f* and /3gh
*bt»ined. Baftneoent of these sasalta l>y least eqjsarea calculation gave the
of ^ * aa 1.61 x 10"9 and ^ h as 1.46 1 10"1S .
1 . K I . »it1y ana P.K. Khcrpkay, J. Inorg. Snol* OIQO., (to be published).
2 . SJI. Heiaon and T.M. Shepherd, J. IttOKg. Kacl. Cheo., 32f 2123 (1965). 5* l . J . C . Bocsotti and H. Soaaottl, She a«teiminati«>fl of the
oonBUat*, Mod»w-Hill Book Co.f Inc. 3few Yoxk (1961).
4 . A. LitoKti and T.S. l i g h t , J. CheM., M* &* 2J6 (1962).
5. OJC. Hdr, Sh.l). tb««is f <JnlTBr»iiy of
- 18 -
1.1.4 Investigations on the ohemlatrr of olutonlum(VIl)
P.R. Hatarajan, 3, Vaidyanathan and M.S. Hagar
In alkaline solutions plutonium(Vli) ia believed to exist in the anionio form FuOji". It is planned to study the extraotion of plutonium(VIl) from alkaline eolations with pyridine which ie known to extract hoptavalent manganese and rhenium fxon alkaline solutions* Preliminary ezperinenta wera caxried oat on the preparation of plutoaium(VIl) in 4 M Jfe,OH by electrolytic oxidation and equilibration with pyridine. They did not show any detectable extraction of plutonium by pyridine* further work ie planned to investigate whether plutonium(VTl) can be stabilized »y some oosrplexing agents*
1.2 Studies in Hadiation Chemistry
1.2.1 Gamma radlolyala of plutonium(lIl)/(lV) system in 0.8S. 68 and 9H hydrochloric aoid solutions
P.R. Hatarajan and M.S. Hagar
Badiation chemistry of plutonium solutions is of interest since Plutonium exists in different oxidation states and a variety c£ reactions oould bo induced by gamma radiations, lurther, as Plutonium i s alpha active, the stabilities of i t s different oxidation states are affected by i t s Own alpha radiations. A study of the radiation chemistry of Plutonium solutions was therefore initiated in this laboratory some time back. The Pa(llt)/(l7) system was chosen for the initial studies since no published incarnation in available on this systen* Earlier investigation in this laboratory in 1-8 M HCl medium showed that the radiolytic .oxidation of Pu(lll) to Pu(iv) waa due only to the 'direct effect* on HCl. Since the radiolytic oxidation ie expected to be at least partly due to 'Indirect effect1 due to the produots of radiolyaie of water, ganana radiolysls of the Pa(lll)/(IV) syotem in 0.8 V HCl was investigated and the results obtained showed that the oxidation was due to 'indirect effect1*1'. Some further investigatiOBS in 0.8 H, 6 Hand 9 H HCl solutions are reported here. The xadiolytio yields-axe interpreted in tone* of probable reactions.
-19 -
0.8 1 HOI solutions
It was observed* * that then m« no further radiolytio oxidation when the mtio of Fu(lll) to Pu(l?) readied a particular Talne In oxygen and argon equilibrated solutions of Pte(lll) in 0.8 8 HC1. In order to eonfixB the attainment of equilibrium, mixtures of Fu(lll) and Ri(lV) in argon or oxygen equilibrated solutions wej» irradiated. She results axe presented in Table 4< Xt was observed that the extent of oxidation in argots equilibrated aolutlona was negligible while that in oxygen equilibrated solution* was quite snail. The yield of HgOg «aa less than the primary sadiolytio yield showing that HOg radioals in oxygen equilibrated solutions do not oxidize Pu(lll) to any 8ignitloant extent when a mixture of and Iu(XV) is irradiated.
TABLB4
Gamoa radiolyois of plutonium(lll)/(iv) system in 0.8H HC1 i Yields of plutoaium(lV) and HO
eV/al
0.59 0.62 O.58
nil 0.10 0.03
0.70 0.53 1.38
0.65 0.43 0.14
0.59 O.54 0.78
In order to check whether part of E Og foraad during radiolysis praasat as the bro*n pesoxy oomplex of Pu(r?)» tae optical, densities of irradiated eolations were measured at the wavaleng&s 4?0e 495 eM 600
the ^ms. £os Pa(l7), brosn psrasy eomples of
- 20 -
ami Pu(lll) respectively. Slnoa toe brown peroxy complex was unstable, the optloal density at 495 nm decreased with tins. The earliest measured optical densities ware used to caloulate the concentration!* of Ptt(lT), brown peroxy eemplex of Ta(Vf) and Pu(lll). 2ha results ax* given in Sable 5. It waa observed that appreciable amounts of peroxy oomplex of Pa(iv) were formed duffing the radiolysis of Pu(lll) aolutions in the presence of atygen* In argon equilibrated solutions there waa negligible amount of paroxy oomplex formed, iinoe the concentration of HgOg was quite low in those aolutieas*
TABUS
_ Time Composition before Composition after radiolysisp radiolyaia
0.36 O.51
0.42
0,61
_, _ M L « v * " / j i. *«v*¥/—i JL *«*\**!/«»/ L Ita\K-J_/ ^ Brown UIBu- Oannia'T 7 iation, M x 103 M x 103 M x 103 M x 103 M x 103 mimtes
9.0 10 1*00 nil 15.0 48 0.41 O.59 28.0 6 0*55 0.62 30.5 10 9.45 0.25 30.5 14 9.20 O.58
Sino» appreciable amounts of H»OA were formed daring the radiolysis of oxygen equilibrated Pn(IT) solutions^, two irradiations were carried oat upto doses 21 x 10 and 28 x 10 eT/ml and optical density measurements were carried out at 495 m a i a function of time. It waa obserred that the deereaaa inabsorbance with time followed first order rate lav indicating the decompo- sition of the brown complex formed during radiolysia.
Jea«iratad plutonlum(lll) solutions
She following procedure was uaed to measure the radiolytio yield of ! •
- 21 -
Solutions were deaerated using a vacuum system and after irradiation the
total gas foraad was Measured using a McLeod gauge» % allowing the gas to
diffuse through heated palladium i t was ascertained that i t was a l l H^ ftes
••attired yields of BL and Pu(iv) in deaerated solutions are given in Figure 9 c
The yields of Eu(XV) oittaioed earl ier in argon equilibrated eolations are
also given in the sane figure for ooBparisoa* The yields of Pu(lV) in argon
equililwatad and de*arated solutions are *sixlj close to eaoh other*
otiserred i n i t i a l values of G ( F U ( I 7 ) ) , oCHgOg) and G(Hg) a s 4 ± 0.4«
0*4 ± 0*1 end 0*9 + 0.1 reopectively.
Peaerated 0.8H HC1 6HHC1
• A o
figure 9 i Eadlolysie of deaerated anS argon aoullitoated Pa(lII) aolutiooa - jial&s of Sfe(I7) and Hge
H* + H + Ptt(lll)
- 2 2 -
The obaewed G^Og) i s OIOM to the expaotod 0B2<>2 in 0.8 1101
»adlaa, iiaoa <fc2<>2 is linearly related to (Cl")1^. She obsarrad <Ktto(l?))
is explained "hgr reaotione ( i ) to ( j ) .
. . . (1)
. . . (2)
. . . (5)
ralaa of °Ce in 0.8 M HC1 BediuB is axpaoted to be eloaa to 4. ^ "The abaaxrad S(Pu(lT)) is oloa* to GCB in&ioatiaff tbat xeaotions (2) and (3)
ax* taking plaea to an aq,oal extant* At higiar doaaa, aa tha oonoantztttion of Itt(in) daeraaaaa and that of fta(l?) inoxeaaaa* tba extant of reaction (2) deoxeasea and that of zeaotlon (3) inoreaeaa antU a atage is xeacW >hen there la no net osidation or rednotion. According to thia xeaotiou sohene, (Kftj) ia also expected to daoxeaae with doee as obaerred. However, the calculated value of the initial O(Hg) ia about 2*2* wbile the obserred valoe ia only 0*9* Oh* reason for thia diaorep&noy is not known.
aqiiilibrated plutW'tyf^yy' solutions
Since thara ia no lurtiier oxidation or redaction daring the rsdielyaia of Fu(lXl) solutions after a certain dose when a Mixture of
and Pu(l7) is foxned, i t i s of intereat to inveBtigate the affeota of acadiation on plutoniu»(lT) solutions • Tba neulta of radiolTSis of wqrgtn eojutilibrated solutions ware preaented inthe last annul report^1 . The reaalta in argon equilibrated solutions are pxaaented her* (lable 6) . The 0(H202) values are well within the priaary radiolytic yield of HgO . Piutonlua(ni i* xtduoed to Pa(ni) wi& a wa l l 0 value.
- 2 3 -
TAELS 6
Dose No. of MUl) Ho* Of H2°2
x 10 IW per ions produoed molecules at v^frrrW t>tn t
10-17 produced/Bl « W r a ) - - . 6 ^ x 10r17
3.9 0.14 0,07 o,36 0.1a 4.9 0.14 0.14 0.29 0.29
21.1 0.21 0.09 0.10 0.04 28.0 0.56 0.27 0.20 0.09
Gamma radlolyaia of argon equilibrated • daasrated and oxygen eouilibrataft BOlutlona In 6 K and 9 H HOI aolutiopg
Tftdiolytio yields of Pu(iv) in 6 N and 9 H HC1 solutions are given in Figuss 9 . The values of G(Pu(w)) axe 1.50+ 0.15 and 2.3 + 0.2 in argon equilibrated and deaezated 6 K HG1 solutions respectively s while i t la 3*0 + 0.3 in argon equilibrated 9 K BC1 solution. Bie reason foe the diaorepanoy In the 6(Pu(lV)) values in argon equilibrated and deasrated 6 M HC1 solutions i s not known. G(HgO2) i s less than 0.1 la a l l cases while C(H2) in deaerated 6 H HC1 solutions 1B 2.3 ± 0.3.
As in the oaso of 0.8 H HC1 solutions, the yields oan be explained by reaotions (1) to (3). In addition, the H and Cl atoms produced by reaction (4) as a reeult of 'diseot effect* also contribute to the yields of Iu(3tf) and Bgo
The extent of reaction (4) i s not knoga. To© obsesmtion that tha O(Pu(JT)) values are less than the expected 60H of 4.5 dm to iuailBaot effect
- 2 4 -
in 6 H anl 9 N HC1 solutions indicates that reaction (3) leading to the reduotion of 5u(l7) by H atoms i s taking place predominantly compared to the extent of reaction (2) leading to the oxidation of Pu(lXl) by E atoms.
Spectrophotcmetrio measurements on Fu(lll) solutions in 6 N irradiated to a dose of about 1 x 1019 eV/nl did not show any indication of the formation of either Fu(Vl) ox the brown peroxy complex of Fu(lV). Experiments were oarxled out to detect any molecular chlorine formed. Argon was passed through Irradiated solution and then through a 0.01 M Cdlg solution. SpQctrophotonstrio analysis of the Cdlg solution did not shop the presence of any free iodine indicating that no detectable quantity of •olecular ohlorine was formed*
The yields of Fu(iv) In oxygett equilibrated 6 H HC1 solutions are shown in Figure 10. Initial G(Pa(l7> was 6.4 + 0.6 and 8.0 + 0.6 in 6 N and 9 N EC1 solutions respectively. The yields remained constant upto a dose of about 4 K 101 aV/nl and then decreased slowly at higher doses. Unlike the results obtained in 0.8 H HGi, oxidation proceeded to completion in 6 H and 9 H HC1 solutions. Initial GCSgOg) was 2*5 + 0»3 in both tha cases of 6 H and 9 H SCI solutions. Howover, the yield of EgO. deoreased rapidly beyond a dose of about 4 x 10 eV/ml in 9 H HC1 solutions while i t appeared to be constant upto about 10 x 10 e7/nl in 6 H SCI solutions* The yield Of Clg was measured in 6 H HC1 solutions and 0(01^) was found to l i e between 0,3 and 0.5,
The increased yields of Pu(l7) in oxygen equilibrated 6 H and 9 H p i solutions as compared to ifae corresponding argon equilibrated solutions BhoT that HQg radicals are caeidislng Pu(lll) to Pu(lv) while H atoms are prtdoaliwntly reducing Pu(l7) to Pu(lll). The H02 radicals team E atoas doe to 'direot •ffeot1 (reaction (4)) also contribute to fee yield of Pta(l?). Vb» decreased yields of BgOg in 6 K and 9 N EC1 solutions ea eonpared to th<«« in 0.8 X HC1 solutions in the presence of oxygen indicate the
of motion (S)
18
10 i Badiolysls of oxygenated plutcniun(lll) solution! yields of plutonium(I7) and H90.
1 • P»R. Kataxajan and M.S. Nagart Bad. Cfaem* Dim. Ana* Bapost for 1970*
B4BC/I-135. p. 15 0971).
1«2*2 Qarora radiolyaia of plutonlum(lll) in nitgio aoid Bolutiona
P.R. Hatamjan and 2.K. Sootos?
(1 A study of the radiolyals of fti(in) in 0.8 IT oitsdo aoi
i n contituation of our inreBtigations in suli&usdo aod bsrteoohlossi
and HHOg wete found to t e the prodaots of rsdioljr©is«.' Biad®
- 26 -
reacted quantitatively with HNOg, i t did not appear aa a produot of radiolysia. Experiments have now been carried out on the radiolyaia of Pu(ll l) in 0.8 N nitric aoid containing salphamio acid whioh zeaota with HNO. and thus protects HgO- from interacting with HHOg. The investigations are also of pzaotioal interest since the process eolations oontain plutoniunf and ferrous sulphamate in nitric aoid medium.
Since only small quantities of BL0o were expected to be formed in argon equilibrated solutions, 10 "II sulphamio acid ma used for preventing the reaction of H-OL, with HHOg. However* in oxygen equilibrated solutions, experiments were carried out with different concentrations of sulphamic aoid at a doae of about 1 x 10 eY/riU The xasults are given in Eable 7* It was observed that 0.1 M eulphamlo aoid was the optimum concentration. Irradiations of oxygen equilibrated solutions were therefore carried out with solutions containing 0.1 M sulphamlo acid.
TABLE 7
EadiolysiB of oxygen equilibrated plutonium(lll) solutions in 0.8 N containing different concentrations of sulphamio aoid
jfBulphanic iaeid_7 11
3.14 2*21
Badiolysis of oxygen equilibrated 0.8 K HHO, oontaining different of aulphamio aoid (0.001, 0.01 and 0.1 M) and no plutonium
also carried out upto a dose of about 6^'i^ 1018^ eTVWl Trith^a vi«w to in^ti^atirig ttie formation of axijr organic produot which4may interfere-in the redox titrinetric method used in these experisents. I t was observed that
- 2 7 -
) «aa about 0.14 in laese solutions indicating that the radiolysis
of aulphaaie aoid' did not produce any organic compound which interfered
•ignifioantly in the redox netbod of measuring lu(lll) and
The yields of Va(Tf) and HgOg in argon and oxygen equilibrated
solutions of Pu(ll l) in O.B N HMO, containing sulphamic aoid are given in
Figure 11* She yields of Pu(iv) in sulphamio acid free solutions obtained
earlier^ are also plotted in the same figure for oomparieon. I t was found
that tiie in i t ia l G(Pu(lV)) was 7*5 ± 0*7 in both argon and oxygen equilibrated
solutions. However* beyond a dose of about 3 x 10 eV/ml, 0<Fu(lV)) decreased
only slowly in oxygen equilibrated solutions but rapidly in argon equilibrated
solutions. The yields were practically the Bane both in the presence arid in
the absence of sulphamic acids The in i t ia l values of ( HgOg) were 0.5 + 0.1
and J.O + 0.3 in argon and oxygen equilibrated solutions respectively.
Speotrophotometric analysis did not indicate the foonatlon of any Ri(Vl). Die
reactions 6 to 10 explain the results obtained.
H + HOj ^ OH" +
2Ptt5+ + S204 + 2H+
OH + HOj + H*
Pu4+
2HN02
. . . (.5)
. . . (T)
. . . (8)
. . . (9)
. . . (10)
The expected value of G(Pu(lV)) from reaotions (6) to (10) i s 6.6. The init ial
G(Eu(I?)) observed wasf however, higher. Eeaotion ( i i ) i s known to, OOCVK in
nitrioi aoid solutions containing Pu( l i l ) .
•'•••* 2R»5<f + HO" + 3H+ — - — ; > 2Pu4+ * HHOg + HgO Vi", (11)
The higher G(EU(I7) ) obseirved ia attributed to raaotion ( i i ) «
of sulphaElc aoid die1, hot afledt'the founation of Ptt(iff)"i'The'''
in the y ie ld of Pu(iv) at higher doses cannot be Sue te
- 26 -
KJXIO1"
Argon Oxygen
Argon
O
Oxygen
Wguire 11 « Badiolysis of pXotonitm(lIl) in nitrio aoid solutions Yields of plutoniun(lV) and E£02
Ptt(lT) and i t s raduotion by H atoms, since tb« initial G(l>u(IV)) of 7-5 obtained eren in solutions nhioh contained appreoiaUe aaountii of Pa(w) prior to ixntdlatlonV'. That the Taxiation of HN02 yield with aose"' Is similar t* Hiat for Ptt(l7) indicates that some internsdiato is foisted as & result
TC-.^ tt* reaction of E atone vit^i HHOg and i t reduces Pu(iv). In oxygen ,, eioilttirated solutions H02 radicals oxidize Pu(lll) gtring rise to the sane
yieldi of Pu(l?).
Aoeording to tha above reaction scbom the ealeelated values for
2 j ) in Argon and eocygen equilibrated solutions containing aolphamlo •eld are about 0.8 and 4«4 respectively. The observed yields were however lower* Further week is necessary to deteraiae the role of sulphaalo acid in tiie radiolysis of Plutonium solutions in HHOL medlun»
Beferenoe
1. P»R. Hatarajan and Z.K. Dootor* Bad. Chem. Diva. Ana. Eaporfc fox 1970,
BABC/l-135t ?• 21 (1971).
1*2*3 EPH atudlaa of intamedlatea fceaad in aeadlolartlo and jcadCK loactions In aqueoua aedina
P.E. Hataxajan. 3 . Taidyanatban and M.S. Hagar
Two methods are known fox 1be study of unstable intexaedlatea in
aqueous nedlun. One i s to atabillaa tben by fxeesing tbs system to liquid
nitrogen temperature and toe other i s to emploj & flow system to build ap
a steady ooneentxation of the intexnediates. Preliminary experiinents have
been eaxxied out on both the methods aainly with a view to getting acquainted
'with Mem. l"ro»n samples of O.O5 II fesrio chloride ia 0.16 M HCl
J at T7*K with gamma radiation ^ii^^'^tQM-of 73 x 10 B
EPR speotrum of the irradiated aaopl© contaiaad thxea l ines at 3244 6,
3275 0 and 3310 6 (Figure 12) . Further work w i l l be devoted towards the
identification of the paramagnstio apecies giving rise to these l i n e s .
For studies with flow system a flow ce l l which could be attached to the
Tarian aqueous sanpl* cel l has been mads and tested. A flow rate of about
4 «1 par a«o. was achieved, ffsing this f i e* ceH fePE spectra ot -fee radicalc
foaed in tiia I l ? + - ELjOg and * ! ? * - ^© 2 - CB^OB yateBia wer® takea snS
they agreed with Ike published spectra. I t i s proposed to ose tenth th©
•*fe<hls for the study of intexmediates feroea i » &
- 3 0 -
Unixradiated.
Figose 12 * Effect of gamma radiation on the EH spaotrua of 0.0^ K FteCl, in 0.16 M HC1 at ?7*K
1*2*4 of nj.'fcri.o aold
PJC. Bhattacharyya and K.D. Sainl
The iapoxtanon of nitrio acid a« a BOlrent in fual xepxooessing i s mil kntira. 8ino« th* radiation ohemiBtry of nitric aold la *t i l l not tttttexstood, cxpaxlMinta «*x« initiated with nain «apha«iB on the deter- •lnati«n of tta yitlda of the important radiolytio prcdueia, EHOg and
It *a» xapoxted earll*; XJi that 0.02 H solphanilaside (SA) oar b« to protect HBOg fsoa reaoting with HgOg in the radiolyeis of aqueous
aitrio fkOlA. OM yroteotlr* aotien ef Si lndieatet that the «aioti»ation
-31 -
HH02 + SA -*•—-> D* .... (1)
+ OH *—^ 1^0 + H02 ... (5)
Siooe no increase in G(HKO2) was observed ^ e a a scavenger foe OH radioel
like iaopropyl alcohol was used in the present ayetem, reaction (3) was
eliminated^2*5 . Hoirever, the G(E8Q$) values in tha preaenoo of 0,02 M SA (2) •
are olose to tha Yaluefl reported by Uahltaaxr ' for HO, system in 0.8 H HgSO in the absence of OH scayoneer. I t was thou^b.t that OH radicals migrt react with 3K according to reactions (4) and (5) with a much faster rate than that of reaction (3) or reaction with isopropyl alcohol.
OH + SA — ^ T ( & , SiOH) . . . (4)
1 + H02 — - — ^ THOg ... (5)
3ne raaotions (6) to (1O) which might affect G(HHOg) nay also be
alcng with reaotiona (1) to (?)•
• o. + NO" > H02 + 2CS" ... (6)
%' + :$> — 2 ^ H ... (7)
?H02 + H20 - *°" > HH02 * H* • NOj . . . (10)
- 52 -
She formation of HO,, by the direct effeot of radiation on N0~ and by reactions (6) and (?) followed by reaction (9) can be considered as this •ouxea of production of HHCL through reaotion (10). Beaotion (8> has not been reported previously but using photogenerated aq as described by Hart^ i t i s now found that at pH 11.5 the rat* of fcQ is of the order of 3.5 x 10? M~1 seo . Thus reaction (&) is practically eliminated because its relative reaotion rate is much lower than i t is for reaotion (6) or (7)* .
The 6(HN02) value in dilate nitrio aoid viz* O.O5 M, where the dlreot effeot of radiation is negligible is O.44 in excellent agreement with-the material balance derived from reactions (5), (6), (7) and (10).
O(HHO2) - £/"g( saq + g(H) -
where g(eaq + g<H) -
and g(OH) - 2.53 • However, a significant increase of G(HH02) with slight increase of nitric aoid concentration cannot be explained by any simple mechanism.
Assuming that reaotions(i) and (2) are competitive and follow the first order kinetics with respect to each reactant equation (11) can be derived t
Kn.
(11)
where? G(HHOg) corresponds to the G-value calculated from the apparent concentration of HNOg forming D+ and £ the ratio of ihe rate constants of reactions(2) and (1) respectively, /"HgOgJ? and /SA_7 indicate the total concentrations of HgOg and sulphanilanide respectively^ If HgOg concentration is nearly oonatant in -foe dose ran|l^and in -foe small range of SA variation i .e . 1O~3 M to 5 x 1<f3 M then & plot of , ^ \ versus A-1. "?" should
pp give a straight lina acoording to equation (11) and this in fact ie shown in Figure 13« Ihus\LKp2J i B Perhaps nearly in steady state concentration. The G(HKO2) corresponding to intercept of figure 13 agrees well with that evaluated
- 33 -
At 0.2 M HHO, irradiated for 10 minutes • f O.5H H ' M » 5 •• A « 1.0H « •• » 10 » Q » 2 .0 H " « it 5 » O * 0.05M » » « 10 •
Figure 13 * ftest of competition for HKO- epeoies between SA. and in "the radiolysla of nitric acid
under a condition nhere reaotion (2) ie not involved in the competition as shoim in SPable 8 .
Although parnitrouo aoid formation was reported*-" to be the intey*
mediate step for the overall raaotion (2) , i t did not interfere with tfae
determination of ooncentmtion of HN02 by an equation similar to equation
( H ) . This was supported by result shown in Figure 14 ohiaainea £x(m thessnal
atudies of several KNO- systens containing BN02 and different concentration
ratios of /HjjOg.J t o fSkJ by jplotting fmOgJ "1 versus /HgOg.J / /"S4J0
The k2/^| values calculated from these straight l ines ara shown ia Sablo 9»
a!he.vatiation of K ^ with HNO concentration i s probably9 duo to ths
-34
X10
O t in 1 M HH0?
• t in 0*2 M HHOj and • t in 0.05 K
figure 14 * TeBt of simple competition for HHOg apaoiea between SA and &,0, in nitric acid, SA • 1 x 10~* H.
iacbantai involved in the diasotisation. The attar reaotion (2) «aa deauritod by Halfpenny and Hobinsonv" t* folio* aiapla firat order kinetioa with raspeot to eaob x«aotant* Bine* 1 /k valusa wars determinsd separatelj foe aaoh concentration of HHO-, thia variation dooa not affaot the preaent xaanlta*
""•"•"" "ThtiB roaotiom of sulphanilaaide and HgOg with HH02 are Bhown to H in ooapttition aad ar« not atfaoted by tht trmiwient apaotsa lita» OB and
*q.• BM ooopetition klnetio axpraaaion aa shown in ecioation ( i l ) can alao b« th« basis for th«de*«Mimtion of O(HHO2).
Present G(BaO2) valuaa eaapazed other published Talus*
Sjwtep Izxadiated Bef. Additive i n a i r estarated solution
0.8 X 4 0.25 X + ©.50 X •
+ 1.t30B •• + 2.00M • + 5-00M •• + 5,00 x .;.*
0o©1 M HHO,
0.42
1.60
k Batio of rate constants-r- from theraal studies
k1 Gono. o f HaHOL added f i x Cono. o f HHOg from i n t e r c e p t i n f i g u r e 14 > 1 x 1O"4 X
•* 0.05 0.20 0.50 1.0 2.0 V M . ; "
r- 5»7 13-4 2O«o 23.8 , ai.e'.
References
1* P.K. Bhattacharyya and R.D. Saini, Convention of Chemists, I . I . T . , Madras, 1970
2. T*J. Sworaki, R.W. Mathews and H.A. Mahlman, Adv. Chem. Sex.* Sj[» 1 64
3 . V. Anbax and P. Beta, Int. J. Appl. Radiation and Isotopes, 1£, 227 (1965)
4. Malcolm DanielB, Adr. Chem. Ser. , @1, 153 (1968).
5. F.J. Miner et a l , USAEC Report RFP-1299, (1969).
6. Klaua Sohimidt and E,J. Hart, Adv. Chem. Ser. , S±t 267
7* B. Halfpenny and P.L. Robinson, J. Chen. Soo», 928 (1952).
1.2*5 Two .phaBe^radiolyala and the effect of radiation on the distribution coefficient of uranium and Plutonium
P.K. Bhattacharyya and R* Yeemraghavan
the extraction of Pu(iv) by trilaurylamine (TLA) in a hydrocarbon
solvent from aqueous nitric aoid solution wae etudied In t h i s ' 1 ' as m i l as
in other laboratories'2^, in riew of i t s application In tte fuel reprocessing
^ 2 5 l r
plants. 0t& of * e ohief merits of TM l isted in the l i terature^» 2 > 5 ' i s that
i t s extraction properties are not affected by radiation, and the reooamendatiot
i s based on Ifas investigation of t ie performance by the irradiated solvent
- 3 7 -
(irradiated in the absence of aqueous phase) upto a dose of 18 mega rads . However, in the plant operation, TLA ia subjected to various types of radiations when i t i s in contact with aqueous acid solutions, depending oat what step of reprocessing i t i s used/* It i s , therefore* likely that the extraction behaviour of the solvent in equilibrium with the aqueous phase under the influence of radiation wi l l be different from that of the post- irradiated solvent. Several reaotive spaelse euoh as Hp0p » HHOL'
v2i dila»rylaminev ' e t c . , produced during the radiolysis of water, nitric acid
and TLA may have an effect on the distribution coefficient (K.) of plutoniua*
Some studies on the radiation chemistry of TLiA- were already reported h^ ue.
In continuation a study of the two phase radiolysis was undertaken and some
of the results are described here.
Preliminary investigations included the distribution behaviour of
nitrous acid, u (Vl) and Pu(lV) in the system in which the organic phase was a 2A?6 (v/v) SLA in xylene solution and the aqueous phase was 1 M UNO, solution*
60 fThe bulk of the mixture of this system was irradiated by Co y-radiation, while i t was kept stirred by a specially designed and remotely controlled
magnetic s t irrer . Plutonium used in theBe experiments was putified f irst by
passing through an anion exchange (Dowex 1 x 4 ) column and then by hydroxide
and peroxide preoipitatlon steps, and finally stored In 7 M HUG, as stock
solution. For the determination of distribution coefficients U(Vl) was
estimated spsctrophotometrically after complexing i t with thiocyanate, and
Plutonium was determined by alpha counting in a proportional counter.
Irradiation upto a dose of 1.5 H rads brought no change in the
acidity of 1 K HHCL.
Nitrous acid i s known to be extracted by TLlS K To estimate the nitrous) acid present in the organic phase, the direct colour development TOthod with sulphanilaJBide and H-1 Baphthylethylene fiiaoina dihydrochlori&s was attempted- Bat the attempt was not successful« TMng 0.02 M salpbanilsmid® ia 2 M acetic aoid 2C^ of the i n i t i a l amount of nitrous aoifi could be
II;, hoieyes, n i tr i te i s ad%d to 1 M HHC solution contain- ^ with 2C^ Thk in xylene, about 9 ^
of nitrous acid remained in -the aqueous phase. Hencs tha loss of nitrous aoid
- 36 -
In &e organic phase my b« due to the formation of nitroBoaaines aa shown
in equation 1. , , -
+ HHO2 » (C12Hg5)2 F - HO + O ^ . O H . . . ( i )
The value of G(HK02) waa detexmined by analysing the aqueous phase (of the
two phase system) containing sulphanilamide for nitrous aoid. The values'.'
are given in Table 10.
TABLE 10
Ho. Dose 0(HN02)
3 1.042 " •
It can be eeen that the value of 6(HH0g) at the lowest dose agrees well with the valoea obtained in radiolyfliB of 1 H HNOL alone. Therefore i t la obrioua that a l l HNOg produced at thia doae ia diaaotised with sulphanilanicle and remained in tie aqueoua phase. Bowevar* the dependence of G(HHO2) on dose ia not oleax.
The effect of radiation on «ie distribution of U(Yl) in the Bystem waa inreatigated upto 0.5 M xad for tf(Vl) ooncentrations of 1-40 an and was found to be negligible*
2
1
0
.04
.09
.69
Plutonian solution ( £taj « 5 m* ) in 1 X HMO, waa irradiated fo*
4 hours in contact witti 20^ TLi in xylet»* which waa not pre-equilibrated
with ni tr io acid. The absorbed dose for this duration oorwsponds to about
0*9 H rad. Tlbe 1^ fox Plutonian waa found to b# 15>'while^a s i a i l s r expariieent
- 3 9 -
ill the fttoanot «f radiation yielded * * 4 value of 8. Plutonium solution was subsequently found (by TTA extraction) to eontain about /$ of Plutonium aft Ptt(tl)* Correction was maae in the calculation of %^ value accounting for fti(Vl)| the miealeuUted Kd values were 47*2 and 12»7 in the present and «boeno# of radiation respectively for Pu(lV). I t can be seen that extr&otion of plutoniura i s mos* In tnfe presence of radiation than in ifee abeano« of i*diation| but i t i» not dear whether this i s due to reduction of laSH extrsotabla Pu(Vl) to tho more «ztraotable J\i(w) by radiolytio produot, HNOg or due to som« otk«r effect. If the reaction between Fu(Vl) and HNO2 la the eausd of enhanoed extraction, this effect would ll>e abaeni in jure 1^(17) solution* Ruettier «xperiwents are in progress to understand the behaviour in
1. M.V. Eamaniah et a l t Roport, BWIC-374 (1?68).
2. A. Chemno, 0. Koohly and A* Bathelliar, Huol. 3 d . and Bng., j£» 557 (t963)«
5« Beoorery of pura plutoxd.ura by extraction with trllaurylamine and diraot preclpitfttion, J.S.O. Tan Geel Baport KFR-188 (Eurochemio) 1966.
4* P.K. Bhattaaharyya and R.P. Saini, Abatzaot 3 P-12-7Oj Convoniion of Cheminta (1970), I . I .T. , Madras.
5* P.K. Bhattaoharyya and R» TfteraraghRvan, Beport, BAIW-5G4 (1966).
6* The determination 6f nitrous sold in purest prooeau solutions» P* Hark«, t. Hurablet, P* Wiohnsrai and B* Eachrioh, Report, ETR-220 (Eurochomio) 1967•
i*&*6 HaBh ifedtoljsJB of aulphanjlamide and othar p-nabstituted
P.K. BhattaoharyjA and H.O. Saini
hydrated eleotroa (*"ftq) plays an important sole in the
«>f nitrate ion to nitrite ion in th« radiolysis of aquecue nitrio aoid
•jr^tMi'^S i * **• eitential to investigate ti« effoot of e<°aq. on eulphsnilaaid®
(8A) bsf^E* using th« latter as a protective agent £©s? HMOg n>* d@@osi%@d i s
1.2*4* t i ^ tois iia vittoi"tKa fiaaotiott of e"*at with SA ©as
<= 4 0 *»
by flash photolysis and to have aa understanding of tha msohasisia isnrolvad therein a number of para-substituted aniline derivatives xihioh asa struct- urally Bimilar to SA were also investigated with sespeet t© thsir with % .
fhe s a t were geasratsd in dilute solution (10°7 - 10 l ) of substanea in a BBtrix consisting of lO"* 1 Bi&GH saturated with pu»i£i©i % gas? % a flash of ultraviolet light » Ths seaotion batesen th® substance and 9aq was followed by monitoring ths oonogntration of ao. with a spsclal
flash spgctrophotomatElc set up at ?00 am. !Ss toehniqu9 ussd was the sams as that deserihed hy Schimidt and HarV ' .
Tha specific rate constants of bimolecular reaction of eaq with para substituted anilines ware determined aai the values are given in Table 11« Soiss of the literature values obtained by ptalae ssdiolysis studies £&s tho reactions of 9aq with mono and Si substituted benssnss ass also given 1m Oiable 11 o
Aribar and Hart^^ cosralated the rate constants of tfea reaotions of aq. with sevejral para substituted benzoates by means of Hammst *@ equation
V afS~ (where /*=> reaotivitjr constant and CTtha eubstituent constant) g
ea shown in Figure 15«> To explain their result they psroposgd a naohanism li assuming that aaq which is knotm to Its a strong Huoleophil© attacks tbs bsasaiaa singe Eoueves, on tfce basis of this assumption i t is very dlffiool to explain the rate constant of the raaotioa of eaq with anil ins whioh is larger by a factor of about 2 than that of fee xoaotioa batweea Qaq and bsnssnQo I t i s also interasting to Bee £sm Slgwa 13 that paffa osiao (p-eubstituted aniline) deviates from the Anbar aM Halt's oossalatioao
if w© tseat oas* voluea of tabl© 11 £a a fashion eiMlai? to
Iby figaye 15 by plottiiag IGJB.. HBL in Figtara 169 thsxa
k
0-9
eoastaa-fe values of •&© reaetioag of substituted tenzeuas and ajailisas
if* sae~* M a s s fE®a Pol0© present . <,«"7 a ie°"7
IT T F TT
OQG
2.1 x
6.8 s 10e 4O6 x 1©8 - . 1.41
1 , 6 X 1 0 1 0 3.06
SOgl^ - - 5<>5 s 1©5 - - 2.13
©mtte
fsaa J ^ C ^ COO** (O»74).
of °@q oa ia?@X?@i i n
ihrfc
a UKQE3o oasfo
) •
go1 Solid coianlexes of uraBBrl ft -diketoaaa gjtfa long chaia aliphatio sulpheaida
M.S. Subrassanian, Mrso Sol*. Pei and ¥.E. lanehamda.
Results of structural studies on ths solid complexes isolated from systems incorporating uranyl ioa with thenoyl trifluoroaoetona (fTi)e
aostylaoetone (aeae) or dibensoyl methana (SHM) with aromatio aHlphosiiSee @uch as diphsnyl (BPSO) aid difcsnzyl (BBSO) sulphCOT idee TOJT© seported saslier • Infrazed and proton magnstie resonance speotj® of these eoraplesee havs indicated a direct donor osygen to uraniura boad and the bidentats character of the two & -diketone moieties. Pur'Hier work with aromatio amis© B-cxides has strengthened the validity of this argument* . In view ©f the relatively higher base strength, of aliphatic sulphoxides with long carbon chains, i t waa of interest to isolate the complexes with them and study ihsig andMR spectra to gain more insight into the nature of bonding of the
The complexes ner@ isolated and purified in tha sens Banner as thoes with aromatio sulphcaides'1 ' . Xa a l l these oompleses the S-0 stretching frequency was found to be decreased by 48 - 100 em" from its value in the neat (free) ligand which is indicative of bonding by the osygen donor« Iho aMphatlo sulphoxides show larger shifts than the aromatio ene@9 which is in keeping with the greater strength of fcfea donor^metal bond in th@ formers
The ME spectra of the ©capiases with di-n-hezyl sulphoKide (SHSO) donor indicate that the terminal mgthyleBis §reup protons nearest to sulphur ara deshielded tc Hie extant of about 40 e/s (from WS) due to the dxalmg© of eleotron density through the S-0 bond, but inst@&d of a t r iplet as in mat BHSO a STaltiplet pattern oonsistiag of 6 lines was observeso oultiplot BtraotaEQ jj& attributed to oonfoxniatioiaally nonaq.uiVGleat group protosB arJsisss as a. £@solt of restricted Eotetiosj about iii@ O S The possibility of saoa restsioted rotation can Its anticipated onlf if I^Q sulph@EidQ is Isondsd t© tfoe matel ^ i c h Eesulte in stesio hindrance of %B
group; 0,^3 psesens© of such rastsiotgd rotation has Hjaoa ad&ucsi
- 45 -
as & direct psoc-f f&r ths donor osjgew to uranium bond.
1» l.So Siabzaaanian and A* Viswarath, J. Inorgo Buol° Chem°9 31, 2575
g» MoS<, SubsamaQian and ToKo Manohandac J« Iaorgo ffacl* Cheia»P J^t, 3001 (1^?1)<
Stability coyrolatloas a«d a.terio effects of synaraiBtio eompleaos
H*S. Subramanian aod VoK» Manehanda
ffiie synsrgistic syatem £w^J ^ "diketmm/osco&m.osj iwestigatad by infrared and distributioE etudlsa to seek some ©oraelatloms on ths stabili ty of the binary ras-at^rl j3°Sik8tos@8 involved in Ihe phencaaaoat. OThe infrared studies were carried out on ths solid synergietie oompleses of the stoiohiometry UOg ( {3 -diketons )2°43 IfyHO /"4Z i HO » para substitutsd pyridins N^osideJZ' ^ e *° *hs solubility of various arains E-osideB i a the aqueous phase, the distribution studies were carried out with the immiscible diiBOatayl sulphosIdG as the oxo donor« Thase studies revealed feat with the incraase O PKraw- £os various |3-<iiketoH389 ttie stretobing frequency of the U-0 ( A-diketone) bond increases linearly whessas carboityl etretohiag frequency decreases linearly ( see Hgurs 17)» From the distribution studi©e i t was observed that the stability oonstant fl for the species TO2(BK)g
liasaxly related to thepKrog of the various ^-diketonosc fhs eathalpy
A ^ of the seaetion UO * (at) • 2HBK (org) ^ tTO2(BK)2 (osg)
Bas founa to bear a l imar relation wit& log k (Figar© 1B) where k is the equilibrium constant for Hi@ above
Sine© "Si© adduot formation in sjrorgism is eloeely related t© th® formation of ostal-ligaad bond, iBHrestigations on th® strang-& of iliis beat
to fes helpful to ©Iseidate ths aatura of syasrgismc Sh© UOg / system was isvestigatst in tha prsseat studies*
seslae of useoyl B -diketos© eempleKss wi^i four dif fessst picollaa I-asia9» J piooliaa l-0£Ms6 S piosliss I-osifi
2 8 I imMdiaa H-OEid®) sith varying dagrase of stesio hiHiamacs TOSS
4 3 0 I68O
- 48 -
by solvent extisotion. SSi© cotaplssos isolated israssu feaM to hsv» H&© ovoal etoiehioaetry TO. ( 8~aiJ®io»aL Z SfrHO m mU@nc@& ftsm msis? asalytloel
Erca iaffeassd studi©® tte& lack ©f eosstaney ia tba shifts Of the I-© stsatehing fx@q.u@noi®s ©a ©oas»lesat£oE appa&ssi to fes eaaesfi hjr tb© at 'uaalf®ss •t S10 sterio effeots f«r •msiom mim S=>esid©B. ®sie iaf©ssn8© Mm tern®. supported by iiie val&gs ef 1T«»0 (B-ocids) s E©t<&img te©K»ef a® shewn ia ifeble 12. Ae &s stretohiag fs®ta®»oy sf©ps®a@nts the seosainatissg a b i l i ^ of tta» ligaraas afjaanca of as? sesaslatioa fcateaaa tfS& aroS V
©tsrie effbots pla^ a signifioan* rol© in «b©e®
2.5 Staflies
2«5«1 Hefineaettfc of ther paeret 1 staaotuEa of aeanyl acalate
H.C. Jayadsvan and 9»Ha
features of thg stjsuoMrs ©f arasayl esalsts W@SB
Saflmmsnt of tho etstiotosal passaisteES leading t© aoeaiate bonfi bond aagles wm achieved by least Bqcaj^s aM F®is?i©s? ©missis bka (a o 0f 1, 2) sssflsotioiaj- sassa osusotsd fo» abeeEpt (0.03 s 0.008 s O0OO8 es5) to ha a eyliMes? ef ssa® ^dias 0»004 With tha f issl gsra'nsta^tke w©S^itsds©©itoal ffeat®9 lg of t&© owEaotaass ©f the ©twaetesa) BBQ feEoaagSit €OBB to a
of Is®
the
19 is tbe (010) p?©3&ofci©» ©f sithia ths aalt call , i l l the at tes asscRia^afl 7^ " • 0.0674 as» sliora as tkiak oii' Loa wkil© atcas at $ e> f- ^ yfl asa l l ^ i t ly Bha€@a<> Ml and boaa aggies axa SIIOBB la ffefels 1|»
is
of fiie esalat® to© osasyl less ooisig a l l the fowt deatats ocalate
atees fos ©e®siisiafcl0Be
•a
n
o »
figure 19 e tJranyl esalato unit cell (010)
j , a 4HgO and sass seatfy formation of a la^gs
J2\
osaLatae aad is profcafoly ssasponsibl© £©2? of solid asalato eompleseB with aetisii&e
Tha ooordination aKeand %s@ asaayl gsoup ie a plaanr pentagon pexpendioulax to the O-TJ-0 axle» these aro two ex&lats gsoups as@ooiat@d the ux&npl ionf each using two oxygen atoms for ooosdimtiora« The individual TT-0 distances axs not significantly diffatant auS &vesa^ to S»47 1 (4)* 0-0 'bitting' distance of 2.6 I of tha sstalate gsoup fsvcurs ^lassas eooxdissatioa pes?panflicHlas to tea O-V-0 axis.
She stxuet&sal a@p90t deeogibgd above leads to the in the UKiiay! oxalato complexes plasms Bantagoml ooordination oslatQ e csialats ions $om stahl© five ssa'bssad sisiga with tho lasaiaium atos ami th© suggested flsaas hesagoBal ocoEdimtion is stesieally
- 51 -
Baferanoet
1 . BoC. Ja^Bdevan and B.M. Chsekaaaburfcty •• Proo. of Chemistry Symposium
(ME)e I . I .T .* Madras, Hov, 25~289 Vol. I , p . 91 (19?O).
2o l . l o Moook, Chento Conm. 11527 (1968).
3 . I«H. ikht&s affid AoJ. Smit'ti, J . Chsm. Soo., D-705 (1969)0
4 . £. Hanson,* Acts Cham, Soaad. 9 |4,9 2969 (19?O)S
5. I0I0 CherByaev Edo "Complex compounds of uranium'9» Eaglish t ransla t ion,
Jerusalem (1966)» pp. 114-144.
2«3»2 Ckalato aad aoetato a<mol@xsB of aotinidee
W0C0 Ja^devan,. S«K» E.H.Ao Dies and Dolt
Thamal deddopoaition of osalato and acatato complexes invariably
leads to mixed metal caidss or «scid@s<> Boss of ths mlsod Eatsl oxides are
diffioult to obtain by heating th@ component oxides. Several oxalato ant
acetato complesse of axanium and nsptuniunt i?sra prepared.
Preparation
Ctealato oompl@s@s of o£anium(vi)
Connies©© tofr-1M?^ais!aK,igt'n^:CS«0y,)«»aH«j10 wesa preparsffl by misting
"hot aquBoaB estiiratsd solvaisloEa' of tSi@ oomponsnt esa la tss im appropriate
prepaiatioas and-allo^ing to cool slos?ly^ • Shsi oempeuuds
2 2 2 2 4 3 metaoa was uijsuits&ie fo» ps©pariag aa-UOgCOgO.)_. Eow©TOff9 i t could ba
pr®pared akQm GSIOQSS of atraoniuta csalats taas afified to oraayl oxalat© tofosa
ths addition of tijsllium
was obtalBad as a toawa p®ud®g ®a tesattag !a IFO9(C 0 ) o
a t 500°0 i a a st3?eaa of dsy afee - I g ^ ieeespessi to 5?ig^gO
t o 95OsCe
Ckalato completes of 5sraniura(iv)
(HE.)MCJ>A).<,3H9O was prepared by dissolving UCC-O.L.fiH-O in stoiohiosstrie ratio in ammonium oxalata and adding an equal voluais of acetone. The solid separated was raashefi with alcohol and ethsr and ds?Sai undas? suction. Ba2
u(C2°4^4'eH20 m 8 Prepared by 1he addition of BaCl£ to an aqueous solution of (ML).U(C2O.)A .3H2O.
T h e ammonium a n * barium somplexes of neptunium were also prepared in an identical way*
iostato complexes of uranium(VX) and nepiui:ium(vi)
The compounds of the typ© given balw were isolated8
Oa*2, 0r*2 9 la"5"2
general me-Siod of preparation was to mix stoiohionstelo amounts of
UOgt&LCOOL.SHpO and the correspoadiug matal acetates in aqueous solutioa
in the presence of a l i t t l e aoetio aeid to prevent the formation of
products. Ths respective me-fcal uranyl acetates were esyatalliaed Sson aqtieoas
solution by fsaotioml reegystalliaation to remove the iapuritisso ()
also isolated in a similar way.
Tfes chemical purities of a l l i&s abo7@ coiapounds starting from
thallium escalates were estsblished by ohssical analysis and supported by
aid s™rsy and infrared speotsal data. "Hie infrared speetm of -&G eomplesss
in agreement with the stxuotures indicated by the formula©.
s-ray data for &e ccmpoimfls are givem in Sibls 14, fhs ssalysis of some of the thallium compounds liks
ass in progr@SB<>
dermal analysis data ar@ summarised in fflsbla 15 o i l l Mis aemplos salts studied decompossd in a i r to form missi motal csii.eB oscopt isa'the oaea of &e ammonium salts ^ie»e TO_ was Stojaaedo Thallium uraai^a asides OB
» 53
K
and
U(Cg0J2 a t 220se ©ad U0g a t 31O°C
^ ^ a t 170°C, BaMO4 -s- BaO2 a t
scateta a t 200°C
(?O0eC)
- 55 -
hoatisg upto HJOQ0© gave U_CL as ths eal^ product* 111 other mis©d asides WOES not affseted by eontimed heating. Hfes ssraooiam uxae^l aestata whaa heated to 200°C dsoompossd to anhydrous uxatyl acetate which othsrwie© is difficult to pr@pa.i@<> This ahowsd polymozphie ohaagsD #»®a eooled to tsmpaEatra© anS hsatad baok to 225°C. These changes uera followed by BfA eiKid X=ray patterns and the xaeults obtained t?era fouad to be in agseoicant with th© polymoirphio bshsvicor of agaajrl asetats reportgi seesntlj
I do ChengraeTr Edo "GomplsE aorapoumds of urauima8Is English
tEaH3latioiae JsHsaelem, pp. 114-144 (1966)0
Barnard F= ISfentssa aed Gex&xd Giovgio •= J. Inorg.
52, P. 1517-1524 (1970).
5 Non-atoiehiometrlg (aides of fee laathanidee
So Sampath aad D>Mo Chaolcmburtty
easth fission produeta forssd in irradiated fuels oould seaet with tha fffiial material da@ to the heat generated fissring th© Qcmial rsaoter eparatios. IH i&ie eoHteaotion tha atudy of misad cocides of lantbanidee and aotinidee i@ of intasset to the pssforjaaaca of esids fuels in
fba xasa earth ^qaiosifies have a stEUCitare whioh io hesagonal aonoeliaic (B) or cuMe (C) arid msy ehctr allotEopic teaEisformation oa Hudeako and Eogancre- ' @ugg@at@d that polymorphic transforEatiosis
by chemical chaages bEiaging aboat f i ^ ehan^s ia ths eompoaitioa of the csidas. ffiis thssmal Seeompositiou of the CEalatos of Eaoclyinijssio eanariffiffiis, ^,&Qlimima9 ^sproeius9 OEMUBS tesbi^m ant yttslus was studiad ia vaeuam to dates^miss ^tiaitiQr ths psoduet obtaisad is sa<^ caoo is stoiohiesetsic cside phase (tha ssalatas give C-typa BgO as daoeapesitis ia aSs?) sabstoiehiGSBt^io osids ®s? s&ami&e elaiBsi to haws beea ©btaiasfi by Saathti® and febag « Kie staiiss was© oags"Sed out oith 100 Eg th® samples in platinaa esnaeibles sisimg a Matties ths^oa.m.lfBas deoompesition ps^aots obtainsi eft 1000° sasa feuM to fes blaeis
» 56 -
sens s=Esy pesdeg iirfsaetiea pattesns ao aoEsal eibis xass She iafSssed apaetsa of tha samples KBES also feiassfi to fee identical to
given in Table 1&»
of oaaple with jgem • O0OO5)
oxide ISO. . . . i .403
Samaciua cride UaO. 1
1« ?<>So Eadenko
Seveasheh,, 2M fessiEi^ad H9S59 78-85 (Stab. 196?) l u s s 0 ) ) .
2o P.O. Gunthas? and H. labaa^t Bssichto dor Isiatseksa
Gasellschsft, 3lt 1771-77
S, Bampath,
For deriving sectirata go&mtitative therasodyiaami© data on arasiitra-plutoaiiam ©to. systems, I t is essential to calibrate the Mettler analyser for ths determination of heats of reaction sad to iwestigate th© effects of change in particle sia©« sample B±ZQS rat© of boating ate* i s serious iharmo&ynainic paramaters. Ths present irork was aimed at achieving this* KEA patterns x?ar© taksn with the analyser for substances lllto sodius ©hloridso lithium nitsatog steasic acids palaitie acid, sodium nitrateD
OC-Rapthol9 bsnsoio aoid, potassiua nitrate t potaseium parohlosstee BIIVGE'
aitrate f ainiaoniuui nitrate and potassium salpbate, ths heats of transitions of ^hioh ar@ betoraQsi 9o5 to 117 oal@ pas graia» CaleiosS aluiaiKa ma uoefi as xefexenoe matezials 100 mg of sample uaa token i s @aeh ease &long uith BTA carves WQEG ofetainad with varyio^ sates of heatiago KIQ psocadurs of
g ^ was aaed for msasuriEg peak fe@as> Kia sspseBsioa ralatiisg to heat of tiansiti©n with peak areas is A H *> -g— stoss© ^ 1 is the heat of transition in cals/graa5 A ° peak area ia sq» cms» II ° mass of iiie sample £ is the ealibratioa cons taut. A E was plotted agaiast A/iSo A straight was obtained and fr-CB ths slope of ilie liaa0 the ealibratioa oomtant was founts to he Qo62 oal/sqo CH. The calibration constaat ma not found to vesy floantly isith vaEsring rates of
Foa? -iie iiweatl^ation of th@ ©ffeots of various paramgtszs oa heats of seaetiOBSs the well kaet?a ^aotioas agnail @i©rHal dsceaposition of feCoO^ O&.0 and laHCOu TOES ohosea and work is uMer my *o evaluat© tike offaots of particle sise9 sespl© ©ize^ » t e of haatiag oa ft i t h & i e
1 . 1.0c B©j?g9 Cei^ts XteriL AeaSo Seio9 49? 648-51 (1945) =
- 5 8 -
2»4»1 Ifossbauer studlea OB some ilmenites
C.K. MathewQj K.H. Hadzaewal® and Aol» Hm©ala
Ilmenita is OK of tha sins mis present in tfea bsach sand d©po®its of Kerala. Whila natural ilmenite found in relatively pare underground or® bads is jsainly FsTiO,, in the beach sands a significant fraction of the is«>a atoms exists in the ferric state presumably as a result of treathsEing ©ffeots. Th® ilstenitos from Chavara aad Maravalakuriohi along tha Kerala coast ass different in compositioa - the former containing about two-thirds of a l l the iron present in tha ferric fora as against em third in tie l a t t e r . The nature of the ferrio iron in these materials i s , however* aot olearly under- stood- Mossbauer studies were carried out on the ilnssaite samples from Chavara and Manavalakuriohi. Measuremants wera carried oat both at room temperature and at liquid nitrogen temperature to see tshether any fresh information can be obtained on the nature of iiie ferrio iron species and also to oheok the validity of tha Bsasuremsnt of ferrous to ferrio rat io from Mossbauer data.
The ilmsnite samples purified by sisving and magnetic separation ^era obtained from the Ore Dressing Section of B.AOH»C. Samples containing about 30 mg of the ilmanites wess mixed with IiiCO- and pressed into aluminium rings to form absorbers in th@ Mossbauer studies» Mossbauer measurements were carried out using a ooastant acceleration spaotrometer •
The Mossbauer absorption speotra of the ilmenites «era measursd both at room temperature and at liquid nitrogen tempsxattire* Tbs speotra are shown in Figures 20 and 21'. All the spsctxs are characterised by three absorption maxima and wexe GBalysod on a three peak model 0 A computes programna was used to mak© a least squares f i t of three IiOEOiatsiaa peaks to the speotra. Efforts to f i t four peaks wess not successful in any of iiie cases. la th© case of the Hanavalakuriohi ilmanit©, the spsetsum taken a t l iqu i i niteogen temperature oould.not bs fitted with even three l>orentsiatt peakso Hanoe in ihia case only the positions of the peaks axe reported, ffce Hossbaue?
59 -
143
4 0 0
20 e loag'bafflag epaetsa of Goaveim ilmanite'&:fe'(a) E©oa amd (b) l iquid ai trogsa t
IBS
IS4
•{::P-f':::-*:;'•-•'}
( 0 )
0 0 0
Ugaro 21 8 Sesaijamer ©PQQ'&JB of at (a)
ass§ givea ia Sabl® 17» Tfea values BE® isprodaaibl© to witfeia
± 0.025
gJBEB
Peak 1
Peak 2
Peak 3
4.99 7.98 544
* r s la t ivo to the eantsoid of -feha sodiom mitEopsfU.asi£Q
In tha abssnoa of cagnetio hypasfim a p l i t t i o g om would
to b© eoiaiJOSQd of ths q.uadxupole-spli% gattsxsis dua to
and fessio i son . Ihua whilo pseks 1 end 3 would soxxespond to The
of the fessoms and forrio doublets saQpaotivalyt. tb® eoatssl $®@&
ths sum of tha other two oomponsats of the doublota.o Ths poaltiosss ©f
second and thtod peaks eoszaspomd to aatural ilmsait® whieb. Sid not
oxidation due to ^eGthsriago She isomar shif t and quad^pol© s p l i t t i n g of the
fenrous iron i a th© ilmenite obtaissd on the bas is ©f ths abwe iatsajw^tetioa
61
as© givoa in liable 13. Hot oaly shift bat also the temperature ±s eharaoteristie of ferrous salts.
ie
If
(a)
M q u i d rd t sogea te>p&