Cationic Ru(II)-CNC pincer complexes (CNC = 2,6-bis(1-methylimidazol-2-ylidene)pyridine), [Ru(CNC)(η²:η²-COD)Cl]Cl (1a) (COD = 1,5-cyclooctadiene), [Ru(CNC)(η²:η²-COD)Cl]PF₆ (1b), [Ru(CNC)(η²-COD)Cl₂] (2), [Ru(CNC)(DMSO)₂Cl]Cl (3a), and [Ru(CNC)(DMSO)₂Cl]PF₆ (3b) have been synthesised and characterised. Single-crystal x-ray diffraction studies of the complexes reveal that the COD ligand remains coordinated to the Ru in η²:η²- and η²-fashion in 1a/b and 2, respectively. The solid-state structure of complex 2 shows an (E,Z) configuration for the η²-COD ligand, instead of the expected (Z,Z) configuration, with the free alkene having an E-configuration. DFT study of isomeric forms of 2 with E,Z- and Z,Z-COD indicates that the complex with Z,Z-COD ligand is thermodynamically more stable and should be favoured in solution. The complexes were investigated for the transfer hydrogenation reaction with 2-propanol and appear to be efficient catalyst precursors with no sign of hydrogenation of the COD ligand during the catalysis.

阳离子 Ru(II)-CNC 钳形配合物 (CNC = 2,6-bis(1-methylimidazol-2-ylidene)pyridine), [Ru(CNC)(η ² :η ² -COD)Cl]Cl ( 1a ) ( COD = 1,5-环辛二烯), [Ru(CNC)(η ² :η ² -COD)Cl]PF ₆ ( 1b ), [Ru(CNC)(η ² -COD)Cl ₂ ] ( 2 ), [已经合成并表征了Ru(CNC)(DMSO) ₂ Cl]Cl ( 3a ) 和 [Ru(CNC)(DMSO) ₂ Cl]PF ₆ ( 3b )。配合物的单晶 X 射线衍射研究表明 COD 配体在 η ² :η 中保持与 Ru 配位² - 和 η ^{2 - 方式}分别在1a/b和2 中。配合物2的固态结构显示 η ² -COD 配体的 (E,Z) 构型，而不是预期的 (Z,Z) 构型，其中游离烯烃具有 E-构型。2与 E,Z- 和 Z,Z-COD的同分异构形式的 DFT 研究表明，与 Z,Z-COD 配体的配合物在热力学上更稳定，应在溶液中使用。研究了配合物与 2-丙醇的转移氢化反应，并且似乎是有效的催化剂前体，在催化过程中没有 COD 配体氢化的迹象。