Unusual reactions of ruthenium–polycyanocarbon complexes: formation of an η2-CNR ligand and cleavage of C(sp2)–CN bonds

Unusual formation of an η2-bonded polycyanocarbon ligand from tetracyanoethene, C2(CN)4 (tcne) and the allylic ligand in Ru{η3-CHPhCHCCPh(CCPh)}(PPh3)Cp∗ (1), and migration of CN from the polycyanocarbon in Ru{C[C(CN)2]CPhC(CN)2}(dppm)Cp∗ (3), have been established by crystal structure determinations on Ru{C(CHCHPh)CPhC[CPhC(CN)2]C(CN)(η2-CN)}(PPh3)Cp∗ (2) and Ru(CN){C(CN)C[CPhC(CN)2]PPh2CH2PPh2}Cp∗ (4), which are the respective products.