Tetrahedral Lewis Base Adducts of an Acyl Preparation and X-Ray Structure of the Pyridine Adduct (n(5)-C5Me5) Cl3Ta (n(2)-OC(SiMe3) (NC5H5))

摘要

The tantalum silyl Cp Cl3TaSiMe3 (Cp = n5-C5Me5) reacts cleanly with carbon monoxide to yield thermally unstable Cp Cl3Ta(n2COSSiMe3) (1). Silaacyl 1 reacts with pyridine to produce the title compound Cp Cl3Ta(n2-OC(SiMe3)9NC5H5) (2), whose crystal structure reveals a Carbon-Nitrogen (pyridine) bond. The lability of the pyridine has been examined by exchange studies with pyridine-d5, the first-order rate law is consistent with a dissociative pathway (k1 = 6.6 + or - 0.8 x .0001 s-1 at -15 C) 2, monoclinic, P2/n,a = 10.322(2)0, b = 14.503(3), c = 16.289(3) A, B = 101.73(1), V = 2392,2(7) A3, Z = 4,RF = 2.62%, RwF = 2.72%.