Three-Coordinate and Four-Coordinate Cobalt Hydride Complexes That React with Dinitrogen

Abstract
We report the formation and N2 reactivity of novel cobalt hydride complexes supported by bulky β-diketiminate ligands (L). Addition of KHBEt3 to LCoCl gives [LCo(μ-H)]2 (1) or K2[LCoH]2 (2), depending on the amount of borohydride used. Compound 2 is the first example of a crystallographically characterized hydride complex in which a transition metal is three-coordinate. Both 1 and 2 react with N2 at room temperature to give dinuclear N2 complexes with loss of H2.