Dicationic lutetium hydride complex stabilized by a meta-cyclophane-derived (NNNC)-type macrocycle

The meta-azacyclophane (Me3TAMC)H (=2,5,8-trimethyl-2,5,8-triaza-meta-cyclophane) reacted with the rare earth metal tris(trimethylsilylmethyl) complex [Ln(CH2SiMe3)3(THF)2] (Ln = Sc, Y, Lu) in THF or benzene to give a Cs-symmetric bis(trimethylsilylmethyl) complex [Ln(Me3TAMC)(CH2SiMe3)2]. The tetradentate (NNNC)-type ligand is formed by metalation of the phenyl group within the macrocycle. In the case of lutetium, abstraction of an alkyl group followed by the treatment of dihydrogen gave the dimeric cationic hydride complex [{(Me3TAMC)Lu(μ-H)(THF)}2][B(3,5-C6H3Cl2)4]2 that was characterized by single-crystal X-ray crystallography.