Preparation and crystal structure of (η5-pentabenzylcyclopentadienyl)- and (η5-cyclopentadienyl)-titanium(III) bis(tetrachloroaluminate) complexes

Article abstract of DOI:10.1016/0022-328X(93)83109-9

The complexes (η⁵-C5Bz5)Ti(AlCl4)2 (Bz = benzyl) (I) and (η⁵-C5H5)Ti(AlCl4)2 (II) were obtained by the redox reaction of (η⁶-C6H6)Ti(AlCl4)2 (III) with the corresponding cyclopentadienes.Single crystal X-ray analysis revealed that I is triclinic (space group P<*>1, a 10.449(2), b 13.530(2), c 17.074(3) Angstroem, α 95.62(2), β 103.89(2), γ 112.70(2) deg) and II is monoclinic (P2₁/n, a 13.710(4), b 13.139(5), c 9.666(2) Angstroem, β 106.90(2) deg).The molecular structures of I and II differ in common features only negligibly from that of III.The C5Bz5 lligand in I exhibits a crown structure with Bz groups orientated uniformly away from the titanium atom.Compound II has a remarkably short Ti-(η⁵-C5H5) ring distance (1.98 Angstroem).Introduction of ethyl (Et) groups into outer positions of aluminate ligands in I induced changes in ESR ad UV-Vis spectra similar to those known for derivatives of II and analogous η⁵-C5Me5 complexes.