Synthesis, structural characterization, and MO calculations of vanadium imido complexes containing bidentate phosphine coligands

Treatment of complex V(N-2,6-(Pr2C6H3)-Pr-i)Cl-3 with 1,2-dimethoxyethane ( dme) gives in quasi-quantitative yield the adduct V(N-2,6-(Pr2C6H3)-Pr-i)Cl -3(dme) (1). Interaction of 1 with bidentate phosphines gives V(N-2,6-(Pr2C 6H3)-Pr-i)Cl-3(P-P) (P-P = depe, 2a; dppe, 2b) compounds. An X-ray analysis (monoclinic, space group P2(1)/c, a = 14.7387 (14) Angstrom, b = 10.6738(1 0) Angstrom, c = 16.999(3) Angstrom, beta = 90.954(2)degrees, Z = 4, R = 0. 0544), carried out on complex 2a, shows a mer arrangement of the chloride l igands and a nonsymmetrical coordination of the diphosphine ligand. One of the phosphorus atoms occupies the trans position with respect to the organo imido ligand. MO calculations on the models V(NR)Cl-3(H2PCH2CH2PH2) (R = H, C6H5) Of complex 2a were performed. The mer isomer, which is more stable t han the fac isomer, shows good agreement with the experimental data.