Binding and Activation of Small Molecules by Three-Coordinate Cr(I)

Abstract

[(i-Pr2Ph)2nacnacCr]2(μ-η2:η2-N2) (2) has been prepared and structurally characterized; it contains a bridging side-on bonded dinitrogen ligand with a N−N distance of 1.249(5) Å. Reactions of this reactive Cr(I) synthon with various small molecules resulted in a series of unusual molecules and transformations; thus CO yielded the binuclear isocarbonyl [(i-Pr2Ph)2nacnacCr]2(CO)(μ-η1:η1-CO)2, ethylene gave [(i-Pr2Ph)2nacnacCr]2(μ-η2:η2-C2H4), O2 oxidatively added to produce (i-Pr2Ph)2nacnacCr(O)2, and azobenzene afforded the product of NN bond cleavage [(i-Pr2Ph)2nacnacCr]2(μ-NPh)2. 2 can be prepared in good yield and affords a facile entry to low-coordinate Cr(I) coordination chemistry.