TITANIUM IMIDO COMPLEXES SUPPORTED BY AMIDINATE LIGANDS - SYNTHESIS, SOLUTION DYNAMICS, AND SOLID-STATE STRUCTURES

Reaction of Li[PhC(NSiMe3)(2)] with the complexes [Ti(NR)Cl-2(py)(3)] affords the corresponding (N,N'-bis(trimethylsilyl)benzamidinato)titan ium imido derivatives [Ti(NR){PhC(NSiMe3)(2)}Cl(py)(2)] [R = Bu-t (1), 2.6-C6H3Me2 (2), 2,6-C6H3Pr2i (3)], which, in solution, exist in temp erature-dependent. dynamic equilibrium with their mono(pyridine) homol ogues [Ti(NR){PhC(NSiMe3)(2)}Cl(py)] and free pyridine. Kinetic and th ermodynamic data for these processes are reported, and the relative co ntributions of the Delta H and Delta S terms associated with all three equilibria are identified. The arylimido complexes 2 and 3 may also b e prepared by treating 1 with the appropriate arylamine. Reaction of L i[MeCO(NC6H11)(2)] with [Ti(NBut)Cl-2(py)(3)] gives the binuclear N,N' -bis(cyclohexyl)acetamidinato derivative [Ti-2(mu-NBut)(2){Me(NC6H11)( 2)}(2)Cl-2] (4) The X-ray structures of 2 and 4 have been determined. Crystal data for 2: triclinic, P (1) over bar, a = 11.219(5) Angstrom, b = 12.131(6) Angstrom, c = 13.208(7) Angstrom, alpha = = 80.34(5)deg rees, beta = 87.41(4)degrees, gamma = 75.13(3)degrees, V = 1722.1(15) Angstrom(3), Z = 2, R = 0.054, R-W = 0.056. Crystal data for 4: tricli nic, P (1) over bar, a = 10.455(3) Angstrom, b = 10.637(5) Angstrom, c = 11.034(3) Angstrom, alpha = 90.52(4)degrees, beta = 112.62(3)degree s, gamma = 114.10(3)degrees, V = 1012.8(10) Angstrom 3, Z = 1, R = 0.0 453, R-W = 0.0495.