Reactions of a triruthenium pentahydrido complex with imines leading to the formation of a perpendicularly coordinated iminoacyl ligand and the scission of a C=N bond on a triruthenium plane

摘要

The reaction of a triruthenium pentahydrido complex, {Cp*Ru(μ-H)} _3(μ _3-H) _2 (1; Cp* = η ~5-C _5Me _5), with N-benzylidenemethylamine resulted in the exclusive formation of a perpendicularly coordinated iminoacyl complex, (Cp*Ru) _3(μ-η ~2:η ~2(⊥)-PhCNMe)(μ-H) _2 (3b), as a result of C-H bond scission of imine. However, the treatment of 1 with N-benzylideneaniline at 100 °C caused C-N bond cleavage to yield the μ _3-benzylidyne- μ _3-phenylimido complex (Cp*Ru) _3(μ _3- CPh)(μ _3-NPh)(μ-H) _2 (7c) and the μ _3- methylidyne-μ _3-phenylimido complex (Cp*Ru) _3(μ _3-CH)(μ _3-NPh)(μ-H) _2 (8). The formation of 7c is in strong contrast to the C-N bond scission occurred in (Cp*Ru) _3(μ-η ~2:η ~2(⊥)- PhCNH)(μ-H) _2 (3a), which required heating at 180 °C. The structural and spectral properties of μ _3-η ~2: η ~2(⊥)-nitrile complex 2, cationic μ 3- η 2:η 2(⊥)-iminoacyl complex 6, and neutral μ _3-η ~2:η ~2(⊥)-iminoacyl complex 3 revealed a clear trend of the activation of the C-N bond on a Ru _3 plane. The thermolysis of 3b proceeded in a different manner to yield a μ _3-methylidyne-μ _3-η ~2(∥) -iminoacyl complex, (Cp*Ru) _3(μ _3-CH) (μ _3-HNCH)(μ-H) (9), as a consequence of both C-N and C-C bond scission.