Nickel Complexes of a Bulky (beta)-Diketiminate Ligand

Nickel(ll) chloride forms a complex with tetrahydrofuran, NiCl2(THF)i.5, that can be used to prepare nickel chloride complexes of a bulky (beta)-diketiminate ligand L [LNiCI and LNUTI-, which have tetrahedral geometries in the solid state, are in equilibrium with three-coordinate LNiCI. Thermodynamic parameters for the equilibrium between [LNiC and LNiCI are AH = 51 (5) kJ/mol and AS = 116(11) J/(mol-K). LNiCI forms a tetrahydrofuran complex with a binding constant of 1.2(2) M at 21 "C. The chloride complexes were used to generate a threecoordinate nickel(ll)-amido complex. This amido complex, LNiN(SiMes)2, is compared with LMN(SiMe3)2 (M = Mn, Fe, Co) (Panda, A.; Slender, M.; Wright, R. J.; Olmstead, M. M.; Klavins, P.; Power, P. P. Inorg. Chem. 2002, 41, 3909-3916). Trends in the metrical parameters of the three-coordinate ..." amido compounds are similar to the trends in three-coordinate LM" chloride compounds (Holland, P. L.; Cundari, T. R.; Perez, L. L.; Eckert, N. A.; Lachicotte, R. J. J. Am. Chem. Soc. 2002, 124, 14416-14424).