The anomalous redox properties of [MoX2(Me8[16]aneS4)], X - Cl or Br, reported previously are rationalised, the authentic reduction of the dibromide occuring at E1/2=–2.87 V versus ferrocinium–ferrocene to give an unstable 17-electron anion which reacts with carbon monoxide and dinitrogen; low temperature cyclic voltammetry shows the [MoBr2(Me8[16]aneS4)]+/0 system to be fluxional and this is explained by a metal ‘in- or out-of-plane’ deformation accompanying conformational rearrangement of the macrocyclic ligand, X-ray crystallography showing the neutral dibromide to have the ‘all-up’ arrangement of the macrocyclic tetrathioether ligand rather than the ‘up–up–down–down’ conformation of the one-electron oxidised species.
先前报道的[MoX2(Me8[16]aneS4)]、X-Cl或Br的异常氧化还原性质得到了合理的解释,二
溴化物的真实还原发生在E1/2=-2.87 V,与
二茂铁-
二茂铁反应生成不稳定的17电子阴离子,该阴离子与
一氧化碳和二氮气反应;低温循环伏安法显示[MoBr2(Me8[16]aneS4)]+/0系统具有流动性,这可以用
金属“平面内或平面外”变形伴随大环
配体的构象重排来解释,X射线晶体学显示中性二
溴化物具有大环四
硫醚
配体的“全向上”排列,而不是一电子氧化物种的“上-上-下-下”构象。