Gold and Nickel Extended Thiophenic-TTF Bisdithiolene Complexes.

ABSTRACT: Gold and nickel bisdithiolene complexes with methyl and tert-butyl substituted thiophenetetrathiafulavalenedithiolate ligands (?-mtdt and ?-tbtdt) were prepared and characterized. These complexes were obtained, under anaerobic conditions, as tetrabutylammonium salts. The diamagnetic gold monoanion (n-Bu?N)[Au(?-mtdt)?] (3) and nickel dianionic species (n-Bu?N)x[Ni(?-mtdt)?] (x = 1,2) (4) were similar to the related non-substituted extended thiophenic-TTF (TTF = tetrathiafulvalene) bisdithiolenes. However the introduction of the large, bulky substituent tert-butyl, led to the formation of a Au (I) dinuclear complex, (n-Bu?N)?[Au?(?-tbtdt)?] (5). The neutral methyl substituted gold and nickel complexes were easily obtained through air or iodine exposure as polycrystalline or amorphous fine powder. [Au(?-mtdt)?] (6) and [Ni(?-mtdt)?] (7) polycrystalline samples display properties of a metallic system with a room temperature electrical conductivity of 0.32 S/cm and ?4 S/cm and a thermoelectric power of ?5 µV/K and ?32 µV/K, respectively. While [Au(?-mtdt)?] (6) presented a Pauli-like magnetic susceptibility typical of conducting systems, in [Ni(?-mtdt)?] (7) large magnetic susceptibilities indicative of high spin states were observed. Both electric transport properties and magnetic properties for gold and nickel [M(?-mtdt)?] are indicative that these compounds are single component molecular conductors.

SUBMITTER: Silva RAL 

PROVIDER: S-EPMC6017561 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature