3-Center-4-Electron Bonding in [(silox)_2Mo=N~tBu]_2(mu-Hg)Controls Reactivity while Frontier Orbitais Permit a Dimolybdenum T-Bond Energy Estimate

摘要

In a continuing investigation into the reactivity of low-coordinate transition metal complexes,d group 6(silox)2M=N~tBu(M=Cr,Mo(1),W(2))species were sought as lower-symmetry analogues to(silox)_3M(M=V,Nb-L(L=4-picoline,PMe3),Ta;silox=~tBu_3SiO).The large singlet-triplet gap accorded(silox)_3Ta renders it stable,whereas the niobium congener has not been isolated.