Charge-Transfer Salts of Octamethylferrocenyl Thioethers and [M(mnt)(2)](-) Complexes (M = Ni, Co, Pt). Synthesis, Structure, and Physical Properties.

The new ferrocene derivatives Fe(eta(5)-C(5)Me(4)SR)(2) (R = Me, 4: R = t-Bu, 5) have been prepared from the corresponding cyclopentadiene and FeCl(2). 5 may be converted to the bis(thiobenzoate) 6, a protected form of dithiol 8. From 6 the octamethyl trithiaferrocenophane 9 may be obtained in good yields. Compounds 4 and 5 are easily oxidized and form paramagnetic salts containing M(mnt)(2) anions (M = Co, Ni, Pt). The derivatives [Fe(eta(5)-C(5)Me(4)SMe)(2)][Ni(mnt)(2)], 14, [Fe(eta(5)-C(5)Me(4)SMe)(2)][Pt(mnt)(2)], 15, [Fe(eta(5)-C(5)Me(4)SMe)(2)][Co(mnt)(2)], 16, [Fe(eta(5)-C(5)Me(4)St-Bu)(2)][Ni(mnt)(2)], 17, [Fe(eta(5)-C(5)Me(4)St-Bu)(2)][Pt(mnt)(2)], 18, and [Fe(eta(5)-C(5)Me(4)St-Bu)(2)][Co(mnt)(2)], 19, have been prepared and fully characterized. X-ray crystal structural studies of 14 and 16-19 have been carried out. 14 and 16 display stacks of strongly interacting M(mnt)(2) anions, whereas 19 contains discrete [Co(mnt)(2)] dimers. 17 and 18 are isomorphous and display a typical D(+)A(-)D(+)A(-) structural motif. SQUID susceptibility measurements indicate a weak ferromagnetic ordering at low temperature for these two compounds.