RuCp* Complexes of Ambidentate 4,5-Diazafluorene Derivatives: From Linkage Isomers to Coordination-Driven Self-Assembly

Abstract

The coordination chemistry of the {RuCp*} + fragment was studied toward several 4,5-diazafluorene derivatives. The ambidentate nature of these 4,5-diazafluorene derivatives with multiple coordination sites allowed for the syntheses of different linkage isomers and self-assembled macrocycles. Both a tetramer ( 2 ) and a monomer ( 3 ) of [RuCp* L ] (where L – = 4,5-diazafluorenide) were prepared with the L – ligand. The dimeric head-to-tail macrocycles [Cp*Ru(L p H)] 2 Cl 2 ( 4 ) and [Cp*RuL p ] 2 ( 5 ) were obtained with the ditopic L p H and L p – ligands (where L p H = 9-(2-(diphenylphosphino)ethyl)-4,5-diazafluorene and L p – = 9-(2-(diphenylphosphino)ethyl)-4,5-diazafluorenide). The bulky arene-substituted L Mes H ligand (where L Mes H = 3,6-dimesityl-4,5-diazafluorene) was prepared, and its coordination to {RuCp*} + gave [Cp*Ru( L Mes H )]Cl ( 13 ). The selective syntheses of different linkage isomers of [RuCp*( L Mes )] ( 14 and 15 ) (where L Mes – = 3,6-dimesityl-4,5-diazafluorenide) were also demonstrated.