EASY FORMATION OF TITANOCENE HYDRIDE-MAGNESIUM COMPLEXES IN THE (C(5)H(5-N)ME(N))(2)TICL2(N=3-5)-DIBUTYLMAGNESIUM SYSTEMS

Complexes [(C(5)H(5-n)Me(n))(2)Ti(mu-H)(2)]Mg-2 (n = 3-5) separate fro m the (C(5)H(5-n)Me(n))(2)TiCl2-Bu(2)Mg (Bu = butyl) systems in toluen e for Mg-to-Ti molar ratios 1-4 as crystalline materials. Crystal stru ctures of the complexes (n = 5 (1): triclinic; P (1) over bar (Z = 2); a = 8.887(2) Angstrom, b = 12.142(4) Angstrom and c = 18.971(6) Angst rom; alpha = 78.96(2)degrees, beta = 86.29(3)degrees and gamma = 74.82 (3)degrees) (n = 4 (2): monoclinic; C2/c (Z = 4); a = 11.331(1) Angstr om, b = 13.177(2) Angstrom and c = 22.989(2) Angstrom; beta = 99.18(1) degrees) (n = 3 (3): triclinic; P (1) over bar (Z = 4); a = 12.603(3) Angstrom, b = 13.629(3) Angstrom and c = 19.561(6) Angstrom; alpha = 7 0.77(2)degrees, beta = 79.36(1)degrees and gamma = 83.41(1)degrees) re vealed a linear Ti-Mg-Ti arrangement with a pseudotetrahedral coordina tion of hydrogen atoms around the central magnesium atom. Ah the compo unds show nearly identical electron spin resonance triplet-state spect ra at g = 1.990 with D = 0.012-0.013 cm(-1) and E = 0, in accordance w ith a nearly constant Ti(III)-Ti(III) distance of 5.54-5.72 Angstrom. The complexes do not induce the polymerization of ethylene on the time scale of a month at room temperature.