Inorganic acceptors

Single-Stack Donor. Ion-radical salts can also be formed from electron donors such as tetrathiafulvalene (TTE) or TMPD (N,N,N N-tetramethyl- phenylene diamine) with inorganic acceptors such as halogens. The resulting stmcture of compounds such as TTE(A)... 

Anaerobic respiration Metabolic process whereby electrons are transferred from an organic, or in some cases, inorganic compounds to an inorganic acceptor molecule other than oxygen. The most common acceptors are nitrate, sulfate, and carbonate. 

The appearance of similar absorption bands has also been observed upon the formation of a complex between the reduced form of cytochrome c and the simple inorganic acceptor Fe(III)(CN)6[106]. The tunneling distance evaluated from the intensity of this band amounts to 7—10 A. However, more recent experiments have failed to detect such a band [107]. The situation is more favourable in the system [cytochrome c/P870] of the Chromatium reaction centre, where the intensity of the charge transfer band centred at 200 nm could be correlated with the data obtained in kinetic experiments [108]. 

Dithiafulvene derivatives behave as -electron donors and form stable charge-transfer complexes and radical ion salts with a wide variety of organic and inorganic acceptor species. 

Table 8-3. Some CT complexes containing [CpJFe] and inorganic acceptors...

Decamethylferrocene has also been used as a donor for the formation of CT complexes with inorganic acceptors. Such acceptors are mainly composed of late transition metal complexes containing planar ligands. Some of these acceptors are illustrated in Scheme 8-3. As for their organic counterparts, the inorganic partners have at least two reversibly accessible oxidation states. The reduced form present in the CT complex is usually a radical anion. 

Powerful inorganic acceptors like the halogens, certain transition metal complexes, and negatively charged counterions with negligible nucleophilic tendency like BFT, CIOT, PFg, AsFg, NOj, CH SO, etc. result in fully ionic phenazine compounds. The physical properties of phenazine salts with inorganic anions have not been extensively or systematically studied. We mention below materials whose structures have been determined. 

The use of aliphatic glycol chloroformates allows the production of OCA and OCM at room temperature and in the absence of organic solvents. The variant yielding OCM based on bisphenol bischloroformates with bischloroformates of aliphatic dihydroxylic compounds in the presence of inorganic acceptors for HCl takes place at temperatures ranging between —10 and 40°C and has been industrialized in Russia. 

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