Reactions of various organotitanium compounds with potentially bidentate alkenyloxo- and related ligands
Abstract
Monoalkoxo-derivatives of titanium(IV) have been synthesised from the potentially bidentate ligand but-3-en-1-ol as four-co-ordinate monomers : [TiCl3(OCH2CH2CHCH2)], (I); [(cp)2TiCl(OCH2CH2CH
CH2)], (II); and [(cp)2TiMe(OCH2CH2CH
CH2)], (III)(cp =η-cyclopentadienyl). The 1 : 1 complex of titanium tetrachloride and 4-methoxybut-1-ene is a chloro-bridged dimer containing six-co-ordinate titanium, {TiCl4(MeOCH2CH2CH
CH2)}2(IV). A variation in the chemical shifts of the olefinic protons in complex (IV), and in (I) and its six-co-ordinate derivatives, has been observed in n.m.r. spectra but it is not considered to be sufficient to imply titanium–olefin bonding. Attempts to prepare models of Ziegler–Natta catalysts by methylation of these compounds have not been successful. Brief reports of reactions of dimethyltitanium dichioride with some uni- and bi-dentate ligands are also given.