Abstract
The d^6^ low‐spin Mn^I^ half‐sandwich dinuclear complexes of the type [{Mn(MeC~5~H~4~)(R~2~PCH~2~CH~2~PR~2~)=C=C(SnMe~3~)}~2~{X}] (X = {μ‐1,4‐C~6~H~4~}, R = Me, 2a; X = {μ‐1,4‐C~6~H~4~}, R = Et, 2b; X = {μ‐1,3‐C~6~H~4~}, R = Me, 3a; X = {μ‐1,3‐C~6~H~4~}, R = Et, 3b; X = {μ‐4,4‐C~6~H~4~‐C~6~H~4~}, R = Me, 4a; X = {μ‐4,4‐C~6~H~4~‐C~6~H~4~}, R = Et, 4b; X = {μ‐1,4‐C~4~H~2~S}, R = Me, 5a; X = {μ‐1,4‐C~4~H~2~S}, R = Et, 5b) were obtained by the treatment of [Mn(C~5~H~4~Me)(η^6^‐cycloheptatriene)] with 0.5 equiv. of the corresponding acetylene Me~3~Sn–C≡C–X–C≡C–SnMe~3~ (X = {μ‐1,4‐C~6~H~4~}, {μ‐1,3‐C~6~H~4~}, {μ‐4,4‐C~6~H~4~‐C~6~H~4~}, {μ‐1,4‐C~4~H~2~S}) and R~2~PCH~2~CH~2~PR~2~ (R = Me, Et) at 50 °C for 12 h to yield the corresponding dinuclear complexes in very good yields. These dinuclear tin‐substituted vinylidene complexes were further treated with an excess of MeOH to give the corresponding dinuclear parent vinylidene complexes of the type [{Mn(MeC~5~H~4~)(R~2~PCH~2~CH~2~PR~2~)=C=C(H)}~2~{X}] (X = {μ‐1,4‐C~6~H~4~}, R = Me, 6a; X = {μ‐1,4‐C~6~H~4~}, R = Et, 6b; X = {μ‐1,3‐C~6~H~4~}, R = Me, 7a; X = {μ‐1,3‐C~6~H~4~}, R = Et, 7b; X = {μ‐4,4‐C~6~H~4~‐C~6~H~4~}, R = Me, 8a; X = {μ‐4,4‐C~6~H~4~‐C~6~H~4~}, R = Et, 8b). All dinuclear compounds were characterised by NMR and IR spectroscopy and elemental analysis. X‐ray diffraction studies were performed on complexes 2b, 3a, 4a and 6a. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)