The salts [NEt4][Ru(CN)(CO)2L(o-O2C6Cl4)] L = PPh3 or P(OPh)3}, which undergo one-electron oxidation at the catecholate ligand to give neutral semiquinone complexes [Ru(CN)(CO)2L(o-O2C6Cl4)], react with the dimers [Ru(CO)2L(µ-o-O2C6Cl4)}2] L = PPh3 or P(OPh)3} to give [NEt4][(o-O2C6Cl4)L(OC)2Ru(µ-CN)Ru(CO)2L′(o-O2C6Cl4)] L or L′ = PPh3 or P(OPh)3}. The cyanide-bridged binuclear anions are, in turn, reversibly oxidised to isolable neutral and cationic complexes [(o-O2C6Cl4)L(OC)2Ru(µ-CN)Ru(CO)2L′(o-O2C6Cl4)] and [(o-O2C6Cl4)L(OC)2Ru(µ-CN)Ru(CO)2L′(o-O2C6Cl4)]+ which contain one and two semiquinone ligands respectively. Structural studies on the redox pair [(o-O2C6Cl4)(Ph3P)(OC)2Ru(µ-CN)Ru(CO)2(PPh3)(o-O2C6Cl4)]− and [(o-O2C6Cl4)(Ph3P)(OC)2Ru(µ-CN)Ru(CO)2(PPh3)(o-O2C6Cl4)] confirm that the C-bound Ru(CO)2(o-O2C6Cl4) fragment is oxidised first. Uniquely, [(o-O2C6Cl4)(PhO)3P}(OC)2Ru(µ-CN)Ru(CO)2(PPh3)(o-O2C6Cl4)]− is oxidised first at the N-bound fragment, indicating that it is possible to control the site of electron transfer by tuning the co-ligands. Crystallisation of [(o-O2C6Cl4)(Ph3P)(OC)2Ru(µ-CN)Ru(CO)2P(OPh)3}(o-O2C6Cl4)] resulted in the formation of an isomer in which the P(OPh)3 ligand is cis to the cyanide bridge, contrasting with the trans arrangement of the X–Ru–L fragment in all other complexes of the type RuX(CO)2L(o-O2C6Cl4).
盐[NEt4][Ru(CN)(CO)2L(o-O2C6Cl4)] L = PPh3 或 P(OPh)3}在
邻苯二酚配体上发生单电子氧化反应,生成中性半醌配合物[Ru(CN)(CO)2L(o-O2C6Cl4)]、与二聚体[Ru(CO)2L(µ-o-O2C6Cl4)}2] L = PPh3 或 P(OPh)3}反应,得到[NEt4][(o-O2C6Cl4)L(OC)2Ru(µ-CN)Ru(CO)2L′(o-O2C6Cl4)] L 或 L′ = PPh3 或 P(OPh)3}。
氰桥双核阴离子反过来会被可逆氧化成可分离的中性和阳离子配合物[(o-O2C6Cl4)L(OC)2Ru(µ-CN)Ru(CO)2L′(o-O2C6Cl4)]和[(o-O2C6Cl4)L(OC)2Ru(µ-CN)Ru(CO)2L′(o-O2C6Cl4)]+,它们分别含有一个和两个半醌
配体。对氧化还原对[(o-O2C6Cl4)(Ph3P)(OC)2Ru(µ-CN)Ru(CO)2(PPh3)(o-O2C6Cl4)]- 和[(o-O2C6Cl4)(Ph3P)(OC)2Ru(µ-CN)Ru(CO)2(PPh3)(o-O2C6Cl4)]的结构研究证实,与 C 结合的 Ru(CO)2(o-O2C6Cl4) 片段首先被氧化。与众不同的是,[(o-O2C6Cl4)(PhO)3P}(OC)2Ru(µ-CN)Ru(CO)2(PPh3)(o-O2C6Cl4)]- 首先在 N 结合片段被氧化,这表明可以通过调整共配位体来控制电子转移的位置。[(o-O2C6Cl4)(Ph3P)(OC)2Ru(µ-CN)Ru(CO)2P(OPh)3}(o-O2C6Cl4)]结晶后形成了一种异构体,其中 P(OPh)3
配体与
氰桥呈顺式排列,这与所有其他 RuX(CO)2L(o-O2C6Cl4)类型复合物中 X-Ru-L 片段的反式排列形成了鲜明对比。