Thermodynamic and Kinetic Investigation of Reactions of Low-Valent Group 6 Complexes with N-Donor Ligands

by Fortman, George Charles

The reactivities of several electron rich, low-valent group 6 complexes with a series of N-donor ligands were explored in order to gain information about the nature of M-N binding. Reactions of trimethylsilyl diazomethane (N=N=CHSiMe3) and 1-adamntyl azide (N=N=NAd) with the organometallic complexes [Cr(CO)3(C5R5)]2 (R = H, Me) and HMo(CO)3(C5R5) (R = H, CH3) were studied from both a kinetic and thermodynamic aspect. Ultimately, this information was used to propose plausible mechanisms by which the reactions take place. Furthermore, reactions of M(PiPr3)2(CO)3 (M = Mo, W; iPr = isopropyl) with N2, trimethylsilyl diazomethane, 1-adamantyl azide, a series of nitriles, and a choice group of N-heterocyclic compounds were studied. The use of the coordinatively unsaturated but sterically hindered M(PiPr3)2(CO)3 complex was used to evaluate the importance of sigma and pi bonding in these complexes.