Room temperature conductivity, dithiolene electrical properties

Very few dithiolene platinum complex-based compounds have been reported and most of them exhibit poor electrical conductivity (9, 122, 123). The complex (Me4N)[Pt(dmit)2]2 does show metal-like behavior (RT conductivity = 10 S cm 1) but only >220 K (123). Another exception is (NHMe3)[Pt(dmit)2]3. This compound, which has the unusual 1 3 stoichiometry, behaves as a metal down to 180 K, with a room temperature conductivity of 140 S cm-1 (91). The Pt(dmit)2 units form pairs with an eclipsed overlap mode. Unlike the analogue Ni derivatives (see above) substituting one hydrogen atom for one methyl group in the (Me4N)+ cation leads to an improvement in the electrical properties. 

A wide range of metal dithiolene complexes have been prepared and their electrical conduction properties reported.111-114 They include neutral, monoanion and dianion complexes with a variety of substituents on the ligand (R = Ph, Me, CN, H, CF3) and a variety of cations. The choice of cation has often been determined by the desire to obtain easily crystallized products and has resulted in the use of rather bulky substituted ammonium salts. The compounds behave as semiconductors with relatively low conductivities at room temperature. It has been shown that the monoanion complexes are considerably more conducting than either the corresponding neutral complex or the dianion, and Rosseinsky and Malpas have proposed that this is related to the ease of disproportionation.113... 

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