Transition-metal dithiolene complexes. Part XV. π-Cyclopentadienyl nitrosyl and related molybdenum complexes
Abstract
The reactions between [{(π-C5H5)Mo(NO)I2}2] and disodium cis-dicyanoethylene-dithiolate, disodium tetrachlorobenzene-1,2-dithiolate, toluene-3,4-dithiol, and bis(trifluoromethyl) dithieten proceed in stages. A variety of complexes, of the type [(π-C5H5)Mo(NO)–(S–S)]2, [(π-C5H5)Mo(NO)(I)–(S–S)],–[(π-C5H5)Mo–(S–S)]2-, and [Mo–(S–S)3]2–, where S–S represents the bidentate dithiolato-ligand, have been isolated. With disodium dicyanoethylene-2,2-dithiolate and NaS2CNR2(R = Me or Et), only [(π-C5H5)Mo(NO)(I)S2C:C(CN)2]– and [(π-C5H5)Mo(NO)(I)S2CNR2], respectively, were isolated; the proton magnetic resonance spectra of the latter indicated that the molybdenum atom was an asymmetric centre and that there was considerable multiple-bond character in the S2C–NR2 link. Treatment of [{(π-C5H5)Mo(NO)S2C2(CN)2}2] in solution with triphenyl phosphite afforded [(π-C5H5)Mo(NO){P(OPh)3}S2C2(CN)2]. A voltammetric examination of the complexes revealed that all species, except the dimers, could be oxidised in a one-electron step, but only [Mo(S2C6Cl4)3]– was synthesised.