Formation of Neutral and Cationic Methyl Derivatives of Titanium Containing Cyclopentadienyl and Aryloxide Ancillary Ligation

Abstract

The series of dimethyltitanium compounds [CpTi(OAr)Me2], ligated by one cyclopentadienyl (Cp) and one 2,6-disubstituted aryloxide (OAr), have been prepared by the reaction of [CpTi(OAr)Cl2] with 2 equiv of LiMe or by the addition of parent phenol (HOAr) to a cold ether solution of [CpTiMe3]. The compounds are stable, except for those containing less bulky o-methyl substituents; the compounds [CpTi(OC6H2Me2-2,6-X-4)Me2] (X = H (19), Br (20)) undergo ligand exchange to produce [CpTi(OC6H2Me2-2,6-X-4)2Me] (X = H (22), Br (23)) and [CpTiMe3]. X-ray crystal structures have been obtained for the dimethyl compounds [CpTi(OC6H2Np-2-But2-4,6)Me2] (13), [CpTi(OC6H2{C10H9}-2-But2-4,6)Me2] (14), [Cp*Ti(OC6HPh2-2,6-But2-3,5)Me2] (15), [CpTi(OC6Ph4-2,3,5,6-Br-4)Me2] (18), [CpTi(OC6H2Me2-2,6-Br-4)Me2] (20), [CpTi(OC6H3Pri2-2,6)Me2] (21), and the monomethyl species 23. Reaction of the dimethyl compounds with [B(C6F5)3] generates the corresponding cationic methyl species [CpTi(OAr)Me][MeB(C6F5)3]. The compound [CpTi(OC6HP...