Charge-transfer salts of octamethylferrocenyl thioethers with organic acceptors (TCNQ and TCNQF(4)) and trihalides (Br-3(-) and I-3(-)). Synthesis, structure, and physical properties

Six charge-transfer (CT) complexes containing three different octamethylfer rocene derivatives (Fe(eta(5)-C5Me4SMe)(2), 1; Fe(eta(5)-(C5Me4SBu)-Bu-t)(2 ), 2; Fe(eta(5)-C5Me4S)(2)S, 3) and TCNQ or TCNQF(4), respectively (4-9), h ave been prepared and fully characterized. X-ray crystal structural studies of 4, 5, 7, and 9 have been carried out. The CT complexes 4 and 5, contain ing TCNQ, display stacks of acceptor molecules with noncommon donor/accepto r stoichiometries of 3:7 for 4 and 1:3 for 5, whereas the charge-transfer c omplexes 7 and 9, containing TCNQF(4), display strongly interacting dimers of acceptor anions. The compounds 4-6 behave as semiconductors with room-te mperature conductivities up to 3.5 S cm(-1) for 6. Magnetic susceptibility measurements indicate strong antiferromagnetic interaction for the (TCNQF(4 ))(3)(2-) dimers in 7-9, the dimers being diamagnetic (S = 0) at room tempe rature. Antiferromagnetic interactions are also observed for the three comp ounds 4-6. To obtain more accurate Lande-g factors for the three possible c ations from 1-3, the corresponding trihalogenide salts with Br-3(-) (10-12) and I-3(-) (13-15) were prepared and fully characterized. Their magnetic p roperties, only deriving from the cations, were measured, and X-ray crystal structural studies have been carried out for the compounds 11, 12, 14, and 15. For the two compounds containing the tert-butyl substituent (11 and 14 ), a DADA structural motif was observed, and with the trithiaferrocenophani um, chains (12) and networks (15) of alternating sulfur bridges and trihalo genide anions were observed.