Symmetry reduction salts

In frozen solution the model complex [Fe4S4(SCH2Ph)4] " gives a RR spectrum (Fig. 22, top), which is readily assignable on the basis of 7 symmetry, whereas the spectrum of the same complex in the [(C2H5)4N] salt (Fig. 22, bottom spectrum) shows band splittings, consistent with the symmetry reduction to D- (elongated cube) observed in the crystal... 

Reduction in cation symmetry (ideally to Cl) lowers the freezing point and markedly expands the range of room-temperature liquid salts. Table 3.1-4 shows the effect of symmetry for a series of [NR4]X salts, in which all the cations contain 20 carbon atoms in the allcyl substituents [44]. 

Regnlar arrays of platinnm were achieved by chemical reduction of a platinnm salt that had been deposited onto the S-layer of Sporosarcina ureae [132]. This S-layer exhibits sqnare lattice symmetry with a lattice constant of 13.2 nm. Transmission electron microscopy revealed the formation of well-separated metal clusters with an average diameter of 1.9 nm. Seven clnster sites per nnit cell were observed. UV-VIS spectrometry was nsed to study the growth kinetics of the clnsters. 

The crystal structures oftetraphenylarsonium [166] and tetraethylammonium [167] salts have been determined and the cluster anion has been found to possess C3V symmetry. Electrochemical studies of stable RBS show the existence of four reduction... 

Liquid [MoFg] is a powerfiil oxidising agent and its reduction with KBr in anhydrous HF or I2 in acetonitrile afforded molybdenum(V) salts of [MoFe]". Molybdenum pentachloride in the gas phase was shown to be monomeric and has C4 symmetry, but is unstable with respect to [Mode]. ... 

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