Transition-metal dithiolene complexes. Part XVI. π-Cyclopentadienyl manganese nitrosyl 1,1-dithiolene complexes

Abstract

The syntheses of the 1,1-dithiolene complexes, [(π-C₅H₅)Mn(NO)S₂C:X]^–, [X = C(CN)·CO₂Et, C(CN)·CO·NH₂ and N·CN], and of [(π-C₅H₅)Mn(NO)S₂C·NR₂](R = Me or Et) are described. Both series of complexes undergo one-electron oxidation reactions which were detected voltammetrically, and the half-wave potentials were dependent on the nature of the sulphur ligand substituents. The NO stretching frequencies of the compounds were also dependent on the sulphur ligand substituents and on the overall charge on the complex. The existence of [(π-C₅H₅)Mn(NO)S₂C·X]⁰ and of [(π-C₅H₅)Mn(NO)S₂C·NR₂]⁺ was confirmed by e.s.r. spectral studies and the g-tensors and Δa_Mn‡ were significantly different from those obtained from the 1,2-dithiolene analogues, [(π-C₅H₅)Mn(NO)S₂C₂R₂]⁰ and [Mn(π-C₅H₅)(NO)S₂C₆Cl₄]⁰.