Van Wazer Structural Reorganization

8/9/2019 Van Wazer Structural Reorganization

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Possible Relevance of the Stochastic Structural Reorganizations

Caused by Instability of Fixed Covalent Bonding in Oxy- Bridged Inorganic

and Organic Polymers which is Suggested to be Relevant to a Fuller

Understanding of the Polymeric Structure of Liquid Water

David Grant

Note 13/4/08

The existence of systems of chemical compounds which

continuously undergo a systematic exchange of parts to form a

stable reproducible mixture of related compounds forms a

definable class of mattermainly associated with the liquid phase

or the suppressed liquid cum solid glassy state. This

phenomenon is encountered with poly-oxy acid chemistriesseveral inorganic elements (e.g. phosphorus, sulphur and boron).

The underlying principles which determine such behaviour is

suggested also to be relevant to the fuller understanding of the

chemistry and physics of liquid water.

Some fifty years ago (the then new methods of NMR and improved

chromatographic separation techniques) showed up serious anomalies in how

pure chemical substances had hitherto been defined.

Some systems of chemical compounds (most typically of pentacovalent

phosphorus oxyacids and their esters) apparently naturally generated under

relatively mild conditions of a complex library of compounds of related

structure which were created by structural reorganizations which apparently

obeyed a set of rules which were found to be generally applicable over a wide

range of chemical situations.

[This phenomenon will also pertain to phosphate diesters in nucleic acidswhich seem endowed with the potential to spontaneously undergo structural

rearrangement under physiological temperature (cf. the self splicing of RNA);

part of the original function of the supramolecular structure of DNA when

viewed from the perspective of non-biological or pre-biological chemistry,

could have evolved to stabilize the phosphodiester backbones against the

spontaneous tendency of polynucleic acid to undergo structural

reorganisation. Contact with catalytically active hydroxyapatite crystal lattice

surfaces may, it can be suggested, putatively override this protection and


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thereby facilitate RNA and DNA scission and rearrangement a process which

could conceivably be relevant to evolution and pathological genetic mutation

e.g. in cancer (cf. Grant et al, 1992)]

Reorganization of some organometallic compounds and

inorganic polymers

Some such compounds are intrinsically unstable as single

molecular species but exist in stable mixtures where the normal

reorganisation mixtures occur.

Attempts to use conventional chemical logic to prepare single

members of such families of normally stable under randomizedconditions chemical compounds show them to reform the stable

mixture in the absence of catalysts.

The randomisation process can be apparently described by a

rigorous obeyed mathematical model.

Examples of this are

polyphosphorous acid and polytetrachloroethylene

and normal water which is suggested to exist as an equilibrated

mixture (i.e. (H2O)n polymers are intrinsically unstable as singlemolecular species).

Van Wazer in 1962 discussed an illustration of this phenomenon for a

formerly supposed stable molecular structure

isotetraphosphoryldimethylamide (I)

Which was originally believed to have been synthesised

according to the conventional organic chemistry logic scheme

[(CH3)2N]2P(O)-O-P(O)(OC2H5)2 + 2ClP(O)[N(CH3)2]2 =>

O-P(O)[N(CH3)2]2


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/

[(CH3)2N]2P(O)-O-P(O)

\

O-P(O)[N(CH3)2]2

(I)

Fig. 1

A preparation which was believed to have this structure gave an 31P NMR

spectrum indicating that no (I) molecules remained; an ambient temperature

pyrolysis had evidently remained undetected during an organic chemistry

logic molecular assembly synthesis pathway or during storage.

Many organophosphorus readily undergo a similar liquid state

facilitated cold-pyrolysis or stochastic scrambling which are

apparently very mild reactions which are not appreciably

exothermic in nature and give near random distribution of

products and those which give highly non-random products

(such reorganizations are associated with more exothermic

processes).

Such scrambled mixtures, especially the near-random types

which can be regarded a fairly precisely definable form of

matter seems in general to be the underlying basis of the

stability of glassy state composite materials (such as the reaction

products of Na2O with SiO2).

Other Phosphorus-Based Oxyacid Systems

Polyphosphorous acid [O-P(O)(-H)-O-]n>2 decomposes rapidly

and non-randomly under ambient temperature conditions to give

phosphine, polyphosphates and some elementary phosphorus.

Attempts to conduct a dehydration polymerization of

phosphorous acid with acetic anhydride however leads to a

quantitative conversion to a highly commercially and

pharmaceutically useful chelating agent, poly-ethane, 1-hydroxy


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1,1- diphosphonic acid (e.g. via a rearrangement of an

intermediately formed diacetyl pyrophosphite derivative

(cf Grant 1979).

Polyphosphoric acid is however a structural stable system but

this is really only strictly correct in terms of the existence of

such polymers as part of a random type reorganization

equilibrium of related molecules.

During the equivalent reaction process between acetic anhydride

and phosphoric acid, polyphosphates are formed and these occur

as a randomly reorganised mixture of variously sized chains and

rings (together with scrambling equilibrium determined amounts

of orthophosphoric acid). The random-type-reorganization

process of the (-OH) to the (=PO) linked central structuralbuilding units [P(O)(OH)3 ortho, P(O)(O-)(OH)2 ends,

P(O)(O-)2 middle and P(O)(O-)3 branch groups] in this system,

with values of the ratio (OH)/P(O) between 0 and 3 (bounded by

phosphorus pentoxide and phosphoric acid) gives rise to a range

of molecules which undergo bond interchange and contains P-

O-P linked polymers, cage molecules, ring molecules and chain

molecules occur which exchange parts with each other).

A similar type of behaviour is apparent for phosphate esters,silicate esters, polysulphides (this basic process of S-S bond

rearrangement also is involved with protein folding and redox

behaviour), polyselenides, arsenates borates and perhaps some

vanadates; a related process seems also to define ligand

exchange on various metal complexes and can be further

exemplified in organic polymer systems (e.g. polyethers).

Evidently the final mixture of such equilibration processes is asa state of matter determined almost entirely by the process of

structural interchange which enables the achievement of a stable

mixture in which the exchange processes produce composite

material systems in which the exchange process continues to

occur in such a manner as to contribute to the stability of the

mixture. Such stochastic structural reorganisation through

ligand exchange may be viewed as a form of pyrolysis

(e.g. viewed as low temperature pyrolysis).


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Organo Chlorine Compound Scrambling

Low temperature pyrolysis seems to be especially common in

phosphorus, arsenic boron, and sulphur chemistry. This seemed

to indicate an unexpected fundamental difference between such

chemistries and the chemistry of molecules which were

composed entirely of carbon skeletons.

An exception to this rule, however, was found for

organochlorine compounds which (albeit at a somewhat highertemperature corresponding to organic pyrolysis conditions but

which could be catlaysed e.g. by Fe and Cu salts) (cf. Grant

1974). All chlorocarbons (organic molecules containing the

atoms of carbon and chlorine only) were found to behave

analogously to phosphorus and other inorganic element based

polymer systems and related covalent compounds in that they

tend to undergo spontaneous decomposition to create an

equilibrated mixture of ligand exchanging molecules. Thisphenomenon is illustrated by attempts to prepare

polytetrachloroethylene; this type of molecular composition

seems to be intrinsically unstable, it undergoing an apparent

rapid decomposition to give a mixture chiefly

hexachlorobenzene, carbon tetrachloride and hexachloroethane,

tetrachloroethylene and chlorine produced by reversible

exchange process involving both the backbone carbon and

chlorine-carbon covalent structures. The large size of chlorineatom could be a critical factor which destablises the fully

chlorinated derivative of polyethylene. Such reorganization

processes may involve free radical intermediates as well as an

exchange of electron pair bonds between structures e.g.

visualized in a conventional non-mathematical chemical

structure pictogram by a concerted movement of electron pairs

between structural building units.


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It should be noted that the chlorocarbon, organophosphorus,

organosilicon and other prone-to-scramble systems are

accurately definable as a state of matter defined in terms of

mathematical equations similar to those required for

thermodynamically determined equilibration processes (plus in

some cases an additional random sorting of the amounts of the

simplest structural building units calculated by these equations)

which allows the prediction of quantity and nature of the

molecular compositions present in such liquid or glassy forms of

matter (e.g. those giving rise to the inorganic oxy-bridged

polymer systems exemplified by polyphosphates,

polyphosphonates, polysilicates, polysulphates, polysulphides as

well as polyethers).

Organometallic Compound Scrambling

Structural reorganisation of unstable organometallic

intermediates has also been indicated to be a possible modus

operandi of Ziegler Natta olefin polymerisation catalysts (cf

Grant 1974).

Water as a System of Structrually Reorganizing Aggregates

A further pertinent example of structural reorganisation

determined state-of-matter is suggested to be liquid water; cf.,

the hydrogen bond scrambling determined nature of liquid

water is generally regarded as containing aggregates of H2O

linked by hydrogen bonds. This might be written (H2O)nwith values of n being estimated at ca.100 at room temperature.

I.e. normal water is actually polywater. However like otherunstable polymers it can be suggested that this also forms a

library of randomly sorted structurally reorganized building

blocks..Polywater then is a real chemical system (on which the

existence of life depends) for which structural reorganization

concept apply. A recent discourse proposes this

in a verbally not mathematically expressed manner (Chaplin

2008).


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In this recent attempt to find a chemical model for liquid water a structure model is

visualised where water structure units move to break up existing cluster and help

create a new cluster which is identical to the old one but only contain a proportion of

the original atoms; this creates a fluctuating self-replicating network of water

molecules with localized band overlapping icosahedral symmetry {first proposed to

exist in liquid water in 1998 and detected in water nanodrops in 2001}. The clusterswere considered to form by interconversion between high and low density forms of

water possibly by bending, not breaking, of some of the hydrogen bonds. Structuring

might, it was suggested, also flicker between statistically and topographically

equivalent clusters involving different molecules which shifted their cluster centres.

The anomalous properties of water (including its change in density the temperature

increases its pressure viscosity behaviour and its the radial X-ray diffraction

distribution pattern) could be explained by the average cluster size, the cluster

integrity and the proportion in the low-density form which all decrease with

increasing temperature (also the model could explain the apparent presence of both

cyclic pentamers and hexamers, the change in properties on supercooling and the

solvation and hydration properties of ions, hydrophobic molecules, carbohydrates andmacromolecules; the concept could also be adapted to a two state structural models

of liquid water into which larger molecules can be mapped in order to offer insights

into their interactions) (cf Chaplin 2008).

References

Van Wazer JR (1962)

Structural reorganization through ligand interchange

American Scientist 50: 450-472Cf., Schwarzman E Van Wazer JR (1961)

J Amer Chem Soc

Principles of phosphorus chemistry. XI. The polyphosphate

esters

J Amer Chem Soc 83: 365-367

Cf also ibid. 1960; 82 6009-6013; cf. p 6013

Grant D Van Wazer JR (1964)Exchange of parts between molecules at equilibrium. V. Alkyl-

terminated chain polysulfides and polyselenides

Ibid. 86: 3012-3017

Van Wazer JR Grant D Dungan CH (1965)

Exchange of parts between molecules at equilibrium. VIII.

Dimethylpolysulfates

Ibid. 87 3333-3330


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Grant D Van Wazer JR Dungan CH (1967)

-disubstuted polymethylphosphonates and

polyphenylpolyphosphonates from condensation polymerization

J Polymer Sci A-1 5 57-75

Grant D (1967)

Redistribution reactions in polymeric alkyl silicates

J Inorg Nucl Chem 29: 69-81

Grant D (1974)

The pertinence of the scrambling behaviour of ligands on

transition-metal centres to Ziegler Natta catalyst activities

J Polymer Sci Polymer Lett Edit 13: 1-9

Grant D (1979)

The rearrangement polymerization of phosphorus acid with

acetic anhydride

Eur Polymer J 15: 1161-1165

Grant D (1974)

The pyrolysis of chlorocarbons

J Appl Chem Biotechnol 24 49-58

Cf Aubrey NE Van Wazer JE (1964)

J Amer Chem Soc 4380-4383

Grant D Long WF Williamson FB (1992)Degenerative and inflammatory diseases may result from

defects in antimineralization mechanisms afforded by

glycosaminoglycans

Medical Hypotheses 38: 49-55, cf. p. 52

Chaplin M (2008)

Water Clusters: Overview, inhttp://www.Isbu.ac.uk/water
http://www.isbu.ac.uk/waterhttp://www.isbu.ac.uk/water


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Van Wazer Structural Reorganization