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STIFTUNG FUR STIPENDIEN AUF DEM GEBIETE DER CHEMIE
Scheme 4
~SnBulAIBN
Me3AIchiralligandgt90 yieldee 20-34
238CHIMIA 5 (19m Nr 5 (Mail
butions This work was financially supported bythe Fonds National Suisse de la Recherche Scien-tifique and by the Stftungfiir Stipendien aufdemGebiete der Chemie through the Alfred WernerFellowship program
Received March 211997
in particular aluminum for these reac-tions We have also developed severaldifferent strategies for the control of thestereochemistry Further investigation ofthe broad and hot topic of catalytic enan-tioselective radical reactions should en-
hance the range of possible applications offree-radical reactions
This work would never have been possiblewithout the enthusiastic assistance of young andtalented coworkers I particularly thank A-RFhal M Gerster and N Moulid for their contri-
[I] DP Curran NA Porter B Giese Stereo-chemistry of Radical Reactions VCH Wein-heim 1995
[2] P Renaud M Ribezzo J Am Chem Soc1991]] 37803 P Renaud N Moufid LHKuo DP Curran J Org Chem 1994 593547
[3] P Renaud T Bourquard M Gerster NMoufid Angew Chem Int Ed 1994 331601
[4] N Moufid P Renaud Hell Chim Acta1995 78 100 I N Moutid P Renaud CHassler B Giese ibid 1995 78 1006
[5] M Gerster L Audergon N Moufid PRenaud Tetrahedron Lett 1996 37 6335
[6] P Renaud M Gerster 1 Am Chem Soc19951176607
[7] M Gerster K Schenk P Renaud AngewChem Int Ed 1996 35 2396
[8] A-R Fhal P Renaud Tetrahedron Lett1997382661
Electronic AsymmetryTheoretical Background LigandDesign and Applications
Chimia 51 (1997) 238-240copy Neue Sclnveizerische Chemische GesellsclllljiISSN 0009-4293
Thomas R Ward
1 Relatives of the dOBent [Cp2ML3]Family An Extended Buckel Molecu-lar Orbital (eHMO) and Structure-Correlation Study of the Edge-Bridged Tetrahedron (EBT -5)
When one thinks offive coordination thetrigonal bipyramid (TB-5) and the squarepyramid (SPY-5) immediately come tomind Their interconversion via the Berrymechanism has been thoroughly studied[5] In the field of dOorganometallic chem-istry the bent metallocene Cp2M frag-ment (Cp = cyclopentadienyl) occupies acentral position Considering cyclopenta-dienyls as six-electron donors occupyinga single coordination site [Cp2ML3] com-
Correspondence Dr TR WardDepartment of Chemistry and BiochemistryUniversity of BernFreiestrasse 3CH-3000 Bern 9
I was born in Fribourg on January 8th 1964 asthe last of six children of John E Ward and AdaLovinger Ward As an American citizen I ob-tained Swiss nationality in 1976 I am married toAnouck Visinand and father of two sons Ben-jamin Roald and SamuelAfter obtaining my baccaaureat from CollegeSt-Michel in June 1983 I entered the Universi-ty of Fribourg the same year as a chemistrystudent I graduated in 1987 with organic chem-istry as major and inorganic chemistry as minorsubjectsMy interests being mostly synthetic but with apronounced taste for group theory I opted for aPhD in organometallic chemistry at the ETH-Zurich in the group of Prof LM Venanzi Theproject I studied dealt with the synthesis and
coordination properties of Crsymmetric phos-phine ligands and their use as acetalizationcatalysts [1][2] This work which was awardedthe ETH Silbermedaille benefited from a fruit-ful collaboration of Prof D Seebach as well asof Ciba-Geigy which patented our systems Ithen moved to Cornell University to work underProf R Hoffmann This theoretical excursionled me into the fascinating field of heteroge-neous catalysis Why is rhodium so efficient atremoving NO from car exhaust [3] On return-ing to Switzerland Ijoined the group of Prof CFloriani for a second postdoc My main focuswas the synthesis of transition-metal carbides[4] Soon thereafter I was awarded the AlfredWerner Fellowship and moved to Bern to un-dertake my independent career in Fall 1993I consider myself as a ligand designer fascinat-ed by chirality My research can be divided intothree stages After having identified a relevantproblem from the current literature I run aseries of qualitative molecular orbital calcula-tions which help me rationalize the publishedobservations Coincidentally these form thebasis for a synthetic project Thus I will de-scribe three distinct projects at different stagesof achievement i) outlining a problem with thehelp of molecular orbital theory ii) designing aligand system and iii) applications
STIFTUNG FUR STIPENDIEN AUF DEM GEBIETE DER CHEMIE 239CHIMIA5 (1997) Nr 5 (Mol
bullbull EBT-5Reversed-Berry Pathway
Electronic Asymmetry )
sterie interectlon (QU ~X~~X Rlonger Pd-C bondyen~
greater eoeffl~ent In LUMO I U
site of nucleophilic attack X = P or N donor
Berry PathwaySPY-5 bull TBP-5
Fig 1 Mapping of the reverse Berry pathway
Fig 2 Frontier-orbital control of the nucleophilic attack on coordinated ailyls
2 If It is not Steric It Must beElectronic
plexes are fi ve-coordinate However thesecompounds cannot be categorized as ei-ther TB-5 or Spy -5 All three ligands Lare contained in the plane sandwichedbetween both cyclopentadienyls but dis-play an acute L-M-L angle laquo70deg) (Fig 1far right) Let me call this unusual geom-etry Edge-Bridged Tetrahedral (EBT-5)
The catalytic properties of dO bentmetallocenes are remarkable I need onlyto mention the stereospecific a-olefin po-lymerization where these catalysts areunrivalled and are the basis of a multibil-lion dollar market of polypropylene In-spection of the widely accepted transition-state geometry involving a bent metal-locene bound to the growing polymer anda propene reveals a [Cp2ML3]-like ar-rangement the third coordination site oc-cupied by an agostic a-H interaction [6]This suggested that the catalytic activityof dObent metallocenes may well be due tothe unusual geometry exhibited by[Cp2ML3] complexes
An eHMO study revealed that theEBT-5 geometry is the result of a second-orderJahn-Teller distortion of e symmetry (inD3h) In fact such a distortion from TB-5corresponds to a reverse Berry pathway Itis favored for all dOsystems which containtwo properly oriented strong 1r-donorsThis model was tested with a structure-correlation analysis of all five-coordinatedOcomplexes possessing two strong 1t-donors A mapping of the reverse Berrypathway is depicted in Fig 1
Fig 3 Pseudo C-symmetric ligands displaying electronic asymmetry
Until recently most of the ligand de-sign for enantioselective catalysis wasbased on steric arguments and C2-sym-metric catalyst precursors Eventuallyelectronically asymmetric bidentate PANand pAS ligands were introduced by PfaltzHelmchen and Williams and proved supe-rior for the palladium-catalyzed allylicalkylation reaction as well as for variousother catalytic applications [7] A theoret-ical study revealed that the pronouncedtrans-influence ofP-donors was responsi-ble for the regioselective nucleophilic at-tack on the terminal allyl carbon with thelongest Pd-C bond [8]
Similarly when an allyl binds to a Crsymmetric catalyst precursor an analo-gous picture arises The C2 symmetry isbroken and as a consequence of stericinteractions one of the terminal Pd-Cbonds is lengthened (Fig 2) NMR exper-iments strongly support regioselectivealkylation at this position Thus not unex-
pectedly steric and electronic argumentsyield the same result
We have designed a new class of elec-tronically asymmetric easily modulablephosphine-phosphinite bidentate ligandswhich are pseudo Cs-symmetric (Fig 3)This guaranties that the enantioselectivityis caused by the electronic asymmetry asthe groove around the metal is nearlyachiral from a steric point of view Thisshould allow us to quantify the importanceof electronic asymmetry in various enan-tioselective catalytic reactions Prelimi-nary results for allylic alkylations as wellas for double bond reduction are highlyencouraging and will be published in duetime
3 An Iron-Based Storage Device
Organisms had developed an addic-tion to iron long before the appearance ofdioxygen on earth Soon thereafter theprimordial soup was rapidly depleted ofvital iron as rust is highly insoluble Even-tually these organisms released si-derophores (iron-sequestering agents) ca-pable of dissolving Fe203 to capture theprecious metal ion As the Felllsiderophorecomplexes are extremely stable the ques-tion arises of how the iron is incorporatedinto the cell where needed To date thereare three working hypotheses J) Reduc-tion of the Felli by NADH which yields alabile Fellsiderophore complex The iron
STIFTUNG FUR STIPENDIEN AUF DEM GEBIETE DER CHEMIE 240CHIMIA 5 (1997) Nr 5 (Mlli)
Received March 2] 1997
[I] J Ott GM Ramos Tombo B SchmidLM Venanzi G Wang TR Ward Tetra-hedron Lett 1989306151
[2] TR Ward LM Venanzi A Albinati FLianza T Gerfin V Gram]ich GM Ra-mos Tombo Helv Chim Acta 1991 74983
[3] TR Ward P A]emany R Hoffmann JPhys Chern 1993 97 7691
[4] L Giannini E Solari S De Angelis TRWard C F]oriani A Chiesi- Villa C Riz-lOli J Am Chern Soc 1995 117 580 I
[5] For a recent review see T Auf der HeydeAngew Chem Int Ed 1994 33 823
[6] HH Brintzinger D Fischer R Miihl-haupt B Rieger RM WaymouthAngewChem Int Ed1995 34 1]43
[7] O Reiser Angew Chern Int Ed 199332547 and refs cited therein
[8] TR Ward OrganometalliCs 1996 152836
[9] A Lutz TR Ward M Albrecht Tetrahe-dron 199652 ]2197
[10] L Zelikovich 1 Libman A Shanzer Na-ture 1995 374 790
information storage This mo]ecular de-vice can be addressed by various meansincluding chiroptical- M6ssbauer- opti-cal spectroscopy as well as magnetochem-ical methods (Fig 4)
N
IN
o 0 0I 10 o 0 0
N N IN N
[Oxidation]eg NEt3 + O2 bull
[Reduction]eg HBF4 + H2
2+
incorporating soft bipyridine and hard sal-icylamide binding sites In the presence ofa single Fe ion and depending on itsoxidation state this latter coordinates se-lectively to one or the other site display-ing very characteristic properties in eachcase
Upon oxidation or reduction the metalion translocates reversibly thus allowing
01[0I 000
~ Fe(lI)deg Fe(lIl) 00 Salicylamide +ttNN Bipyridine
Amax 570 nm (e 5040) Amax 450 nm (e 2490)Amax 540 nm (e 4470)Fig 4 An iron-hased
molecular switch
can then be transferred to a softer nitrogenligand sphere such as porphyrins bettersuited to its oxidation state 2) Protonationof the FeIIlsiderophore favoring its re-lease 3) Enzymatic degradation of thesiderophore
In order to mimic the iron release-incorporation mechanism we [9] and oth-ers [10] have designed tripodal ligands
Tailored Receptors for Supra-molecular Lanthanide Devices
Chimia 5 (997) 240-242copy Neue Schweizerische Chemische GesellschaftISSN 0009-4293
Claude Piguet
Although the lanthanide metal ions LnllIare considered as the chameleons of co-ordination chemistry because of their weakdative bonds with common ligands theirvariable coordination numbers and limit-ed stereochemical preferences theirpecu-liar 4f electronic configurations have at-tracted much attention for the design ofmolecular devices such as contrast agentsin MRI shift reagents in NMR lumines-cent stains for f1uoroimmunoassays andDNA labelling and catalysts for selectiveRNA sequencing [1] A close structuralcontrol of the coordination site and the
Correspondence Dr C PiguetDepartment of Inorganic Analyticaland Applied ChemistryUniversity of Geneva30 quai Ernest AnsermetCH-121] Geneve 4
Claude Piguet was born in Geneva (Switzer-land) in ] 961 He studied chemistry at theUniversity of Geneva and received his MSdegree in Chemistry in 1986 From 1986 to1989 he was a graduate student at the Depart-ment of Inorganic Chemistry of the Universityof Geneva where he obtained his PhD thesiswith felicitations in ]989 in the domain ofcoordination chemistry and dioxygen complex-
es He pursued his formation as a postdoctoralfellow in the group of Prof i-M Le1Il at theUniversity ofStrasbourg France (1989-1990)then he returned to Geneva in the group of ProfAF Williams (1990-1994) and finally movedto Lausanne Switzerland in the group of Profi-CG Biinzli (1995) In 1995 he received theWerner Medal of the New Swiss ChemicalSociety for his researches in the field of su-pramolecular chemistry of lanthanide metalions and luminescent sensors Since 1995 he isLecturer in the DepartmentofInorganic Chem-istry at the University of Geneva and recipientof the Alfred Werner Grant for the projectToward Organized Luminescent Materia]sHis research topics and interests are the me-thodical studies of self-assembled supramo-]ecular complexes with d-block and f-blockmetal ions the deve]opmentoflanthanide probesand sensors with predetermined structural pho-tophysical and magnetic properties and thepreparation of luminescent metallomesogenscontaining lanthanide metal ions
STIFTUNG FUR STIPENDIEN AUF DEM GEBIETE DER CHEMIE 239CHIMIA5 (1997) Nr 5 (Mol
bullbull EBT-5Reversed-Berry Pathway
Electronic Asymmetry )
sterie interectlon (QU ~X~~X Rlonger Pd-C bondyen~
greater eoeffl~ent In LUMO I U
site of nucleophilic attack X = P or N donor
Berry PathwaySPY-5 bull TBP-5
Fig 1 Mapping of the reverse Berry pathway
Fig 2 Frontier-orbital control of the nucleophilic attack on coordinated ailyls
2 If It is not Steric It Must beElectronic
plexes are fi ve-coordinate However thesecompounds cannot be categorized as ei-ther TB-5 or Spy -5 All three ligands Lare contained in the plane sandwichedbetween both cyclopentadienyls but dis-play an acute L-M-L angle laquo70deg) (Fig 1far right) Let me call this unusual geom-etry Edge-Bridged Tetrahedral (EBT-5)
The catalytic properties of dO bentmetallocenes are remarkable I need onlyto mention the stereospecific a-olefin po-lymerization where these catalysts areunrivalled and are the basis of a multibil-lion dollar market of polypropylene In-spection of the widely accepted transition-state geometry involving a bent metal-locene bound to the growing polymer anda propene reveals a [Cp2ML3]-like ar-rangement the third coordination site oc-cupied by an agostic a-H interaction [6]This suggested that the catalytic activityof dObent metallocenes may well be due tothe unusual geometry exhibited by[Cp2ML3] complexes
An eHMO study revealed that theEBT-5 geometry is the result of a second-orderJahn-Teller distortion of e symmetry (inD3h) In fact such a distortion from TB-5corresponds to a reverse Berry pathway Itis favored for all dOsystems which containtwo properly oriented strong 1r-donorsThis model was tested with a structure-correlation analysis of all five-coordinatedOcomplexes possessing two strong 1t-donors A mapping of the reverse Berrypathway is depicted in Fig 1
Fig 3 Pseudo C-symmetric ligands displaying electronic asymmetry
Until recently most of the ligand de-sign for enantioselective catalysis wasbased on steric arguments and C2-sym-metric catalyst precursors Eventuallyelectronically asymmetric bidentate PANand pAS ligands were introduced by PfaltzHelmchen and Williams and proved supe-rior for the palladium-catalyzed allylicalkylation reaction as well as for variousother catalytic applications [7] A theoret-ical study revealed that the pronouncedtrans-influence ofP-donors was responsi-ble for the regioselective nucleophilic at-tack on the terminal allyl carbon with thelongest Pd-C bond [8]
Similarly when an allyl binds to a Crsymmetric catalyst precursor an analo-gous picture arises The C2 symmetry isbroken and as a consequence of stericinteractions one of the terminal Pd-Cbonds is lengthened (Fig 2) NMR exper-iments strongly support regioselectivealkylation at this position Thus not unex-
pectedly steric and electronic argumentsyield the same result
We have designed a new class of elec-tronically asymmetric easily modulablephosphine-phosphinite bidentate ligandswhich are pseudo Cs-symmetric (Fig 3)This guaranties that the enantioselectivityis caused by the electronic asymmetry asthe groove around the metal is nearlyachiral from a steric point of view Thisshould allow us to quantify the importanceof electronic asymmetry in various enan-tioselective catalytic reactions Prelimi-nary results for allylic alkylations as wellas for double bond reduction are highlyencouraging and will be published in duetime
3 An Iron-Based Storage Device
Organisms had developed an addic-tion to iron long before the appearance ofdioxygen on earth Soon thereafter theprimordial soup was rapidly depleted ofvital iron as rust is highly insoluble Even-tually these organisms released si-derophores (iron-sequestering agents) ca-pable of dissolving Fe203 to capture theprecious metal ion As the Felllsiderophorecomplexes are extremely stable the ques-tion arises of how the iron is incorporatedinto the cell where needed To date thereare three working hypotheses J) Reduc-tion of the Felli by NADH which yields alabile Fellsiderophore complex The iron
STIFTUNG FUR STIPENDIEN AUF DEM GEBIETE DER CHEMIE 240CHIMIA 5 (1997) Nr 5 (Mlli)
Received March 2] 1997
[I] J Ott GM Ramos Tombo B SchmidLM Venanzi G Wang TR Ward Tetra-hedron Lett 1989306151
[2] TR Ward LM Venanzi A Albinati FLianza T Gerfin V Gram]ich GM Ra-mos Tombo Helv Chim Acta 1991 74983
[3] TR Ward P A]emany R Hoffmann JPhys Chern 1993 97 7691
[4] L Giannini E Solari S De Angelis TRWard C F]oriani A Chiesi- Villa C Riz-lOli J Am Chern Soc 1995 117 580 I
[5] For a recent review see T Auf der HeydeAngew Chem Int Ed 1994 33 823
[6] HH Brintzinger D Fischer R Miihl-haupt B Rieger RM WaymouthAngewChem Int Ed1995 34 1]43
[7] O Reiser Angew Chern Int Ed 199332547 and refs cited therein
[8] TR Ward OrganometalliCs 1996 152836
[9] A Lutz TR Ward M Albrecht Tetrahe-dron 199652 ]2197
[10] L Zelikovich 1 Libman A Shanzer Na-ture 1995 374 790
information storage This mo]ecular de-vice can be addressed by various meansincluding chiroptical- M6ssbauer- opti-cal spectroscopy as well as magnetochem-ical methods (Fig 4)
N
IN
o 0 0I 10 o 0 0
N N IN N
[Oxidation]eg NEt3 + O2 bull
[Reduction]eg HBF4 + H2
2+
incorporating soft bipyridine and hard sal-icylamide binding sites In the presence ofa single Fe ion and depending on itsoxidation state this latter coordinates se-lectively to one or the other site display-ing very characteristic properties in eachcase
Upon oxidation or reduction the metalion translocates reversibly thus allowing
01[0I 000
~ Fe(lI)deg Fe(lIl) 00 Salicylamide +ttNN Bipyridine
Amax 570 nm (e 5040) Amax 450 nm (e 2490)Amax 540 nm (e 4470)Fig 4 An iron-hased
molecular switch
can then be transferred to a softer nitrogenligand sphere such as porphyrins bettersuited to its oxidation state 2) Protonationof the FeIIlsiderophore favoring its re-lease 3) Enzymatic degradation of thesiderophore
In order to mimic the iron release-incorporation mechanism we [9] and oth-ers [10] have designed tripodal ligands
Tailored Receptors for Supra-molecular Lanthanide Devices
Chimia 5 (997) 240-242copy Neue Schweizerische Chemische GesellschaftISSN 0009-4293
Claude Piguet
Although the lanthanide metal ions LnllIare considered as the chameleons of co-ordination chemistry because of their weakdative bonds with common ligands theirvariable coordination numbers and limit-ed stereochemical preferences theirpecu-liar 4f electronic configurations have at-tracted much attention for the design ofmolecular devices such as contrast agentsin MRI shift reagents in NMR lumines-cent stains for f1uoroimmunoassays andDNA labelling and catalysts for selectiveRNA sequencing [1] A close structuralcontrol of the coordination site and the
Correspondence Dr C PiguetDepartment of Inorganic Analyticaland Applied ChemistryUniversity of Geneva30 quai Ernest AnsermetCH-121] Geneve 4
Claude Piguet was born in Geneva (Switzer-land) in ] 961 He studied chemistry at theUniversity of Geneva and received his MSdegree in Chemistry in 1986 From 1986 to1989 he was a graduate student at the Depart-ment of Inorganic Chemistry of the Universityof Geneva where he obtained his PhD thesiswith felicitations in ]989 in the domain ofcoordination chemistry and dioxygen complex-
es He pursued his formation as a postdoctoralfellow in the group of Prof i-M Le1Il at theUniversity ofStrasbourg France (1989-1990)then he returned to Geneva in the group of ProfAF Williams (1990-1994) and finally movedto Lausanne Switzerland in the group of Profi-CG Biinzli (1995) In 1995 he received theWerner Medal of the New Swiss ChemicalSociety for his researches in the field of su-pramolecular chemistry of lanthanide metalions and luminescent sensors Since 1995 he isLecturer in the DepartmentofInorganic Chem-istry at the University of Geneva and recipientof the Alfred Werner Grant for the projectToward Organized Luminescent Materia]sHis research topics and interests are the me-thodical studies of self-assembled supramo-]ecular complexes with d-block and f-blockmetal ions the deve]opmentoflanthanide probesand sensors with predetermined structural pho-tophysical and magnetic properties and thepreparation of luminescent metallomesogenscontaining lanthanide metal ions
STIFTUNG FUR STIPENDIEN AUF DEM GEBIETE DER CHEMIE 240CHIMIA 5 (1997) Nr 5 (Mlli)
Received March 2] 1997
[I] J Ott GM Ramos Tombo B SchmidLM Venanzi G Wang TR Ward Tetra-hedron Lett 1989306151
[2] TR Ward LM Venanzi A Albinati FLianza T Gerfin V Gram]ich GM Ra-mos Tombo Helv Chim Acta 1991 74983
[3] TR Ward P A]emany R Hoffmann JPhys Chern 1993 97 7691
[4] L Giannini E Solari S De Angelis TRWard C F]oriani A Chiesi- Villa C Riz-lOli J Am Chern Soc 1995 117 580 I
[5] For a recent review see T Auf der HeydeAngew Chem Int Ed 1994 33 823
[6] HH Brintzinger D Fischer R Miihl-haupt B Rieger RM WaymouthAngewChem Int Ed1995 34 1]43
[7] O Reiser Angew Chern Int Ed 199332547 and refs cited therein
[8] TR Ward OrganometalliCs 1996 152836
[9] A Lutz TR Ward M Albrecht Tetrahe-dron 199652 ]2197
[10] L Zelikovich 1 Libman A Shanzer Na-ture 1995 374 790
information storage This mo]ecular de-vice can be addressed by various meansincluding chiroptical- M6ssbauer- opti-cal spectroscopy as well as magnetochem-ical methods (Fig 4)
N
IN
o 0 0I 10 o 0 0
N N IN N
[Oxidation]eg NEt3 + O2 bull
[Reduction]eg HBF4 + H2
2+
incorporating soft bipyridine and hard sal-icylamide binding sites In the presence ofa single Fe ion and depending on itsoxidation state this latter coordinates se-lectively to one or the other site display-ing very characteristic properties in eachcase
Upon oxidation or reduction the metalion translocates reversibly thus allowing
01[0I 000
~ Fe(lI)deg Fe(lIl) 00 Salicylamide +ttNN Bipyridine
Amax 570 nm (e 5040) Amax 450 nm (e 2490)Amax 540 nm (e 4470)Fig 4 An iron-hased
molecular switch
can then be transferred to a softer nitrogenligand sphere such as porphyrins bettersuited to its oxidation state 2) Protonationof the FeIIlsiderophore favoring its re-lease 3) Enzymatic degradation of thesiderophore
In order to mimic the iron release-incorporation mechanism we [9] and oth-ers [10] have designed tripodal ligands
Tailored Receptors for Supra-molecular Lanthanide Devices
Chimia 5 (997) 240-242copy Neue Schweizerische Chemische GesellschaftISSN 0009-4293
Claude Piguet
Although the lanthanide metal ions LnllIare considered as the chameleons of co-ordination chemistry because of their weakdative bonds with common ligands theirvariable coordination numbers and limit-ed stereochemical preferences theirpecu-liar 4f electronic configurations have at-tracted much attention for the design ofmolecular devices such as contrast agentsin MRI shift reagents in NMR lumines-cent stains for f1uoroimmunoassays andDNA labelling and catalysts for selectiveRNA sequencing [1] A close structuralcontrol of the coordination site and the
Correspondence Dr C PiguetDepartment of Inorganic Analyticaland Applied ChemistryUniversity of Geneva30 quai Ernest AnsermetCH-121] Geneve 4
Claude Piguet was born in Geneva (Switzer-land) in ] 961 He studied chemistry at theUniversity of Geneva and received his MSdegree in Chemistry in 1986 From 1986 to1989 he was a graduate student at the Depart-ment of Inorganic Chemistry of the Universityof Geneva where he obtained his PhD thesiswith felicitations in ]989 in the domain ofcoordination chemistry and dioxygen complex-
es He pursued his formation as a postdoctoralfellow in the group of Prof i-M Le1Il at theUniversity ofStrasbourg France (1989-1990)then he returned to Geneva in the group of ProfAF Williams (1990-1994) and finally movedto Lausanne Switzerland in the group of Profi-CG Biinzli (1995) In 1995 he received theWerner Medal of the New Swiss ChemicalSociety for his researches in the field of su-pramolecular chemistry of lanthanide metalions and luminescent sensors Since 1995 he isLecturer in the DepartmentofInorganic Chem-istry at the University of Geneva and recipientof the Alfred Werner Grant for the projectToward Organized Luminescent Materia]sHis research topics and interests are the me-thodical studies of self-assembled supramo-]ecular complexes with d-block and f-blockmetal ions the deve]opmentoflanthanide probesand sensors with predetermined structural pho-tophysical and magnetic properties and thepreparation of luminescent metallomesogenscontaining lanthanide metal ions
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