Homo- and Heterometallic Aluminum and Titanium Complexes of Tridentate (OSO) Ligand:  Synthesis, Structure, and Catalytic Activity

Abstract

The tridentate (OSO-functions) biphenol, 2,2‘-thiobis{4-(1,1,3,3-tetramethylbutyl)phenol} (tbopH2), reacts with AlMe3 to give [Al2(μ-tbop-κ3O,S,O)2Me2] (1). Alcoholysis of 1 results in the formation of [Al2(μ-OEt)2(tbop-κ3O,S,O)2] (2). The reaction of 2 with TiCl4 gives the trimeric complex [Ti3(μ-OEt)2(μ-tbop-κ3O,S,O)2Cl6] (3)·C6H14. Alkylation of 3·C6H14 with LiMe produces two dimeric complexes, [Ti2(μ-tbop-κ3O,S,O)2Me4] (4) and [Ti2(μ-OE)2(tbop-κ3O,S,O)2Me2] (5)·Et2O. Treatment of [Ti2(μ-OEt)2(tbop-κ3O,S,O)2(OEt)2] with AlMe3 and EtOH afforded the heterobimetallic species, [Ti2Al2(μ-OEt)6(μ-tbop-κ3O,S,O)2(OEt)4] (6). The structures of 1−6 were confirmed by NMR spectroscopy; complexes 1, 3·C6H14, 5·Et2O, and 6 were further investigated by X-ray crystallography. Compounds 3−6, when supported on MgCl2 and activated with aluminum alkyls, effectively polymerize ethene.

Organogallium complexes incorporating tridentate thioetherbiphenolate ligands 2,2′-thiobis(4,6-di-tert-butylphenolate), Stdiol and 2,2′-thiobis(4,6-dimethylphenolate), Smdiol

“…Wasserman informed on aluminium compounds derived of tridentate thiobisphenolate ligands and showed they are efficient catalysts for ethylene oxide polymerization [39]. Okuda [40] and Janas [41] have reported new aluminium and aluminium/titanium derivatives of similar ligands with structures related to those of our own unpublished work and some of the presented herein.…”

Synthesis and Characterization of Dichlorotitanium Alkoxide Complex and Its Activity in the Polymerization of α-Olefins

“…The corresponding proton NMR signals for the bridging ethoxide are found at 3.37 and 0.92 ppm, similar to the complex proposed by Janas. 75 Ultimately, one of the methyl groups is abstracted by MAO to give the putative cationic complex 4. We propose complex 4 as the plausible active species in the polymerization.…”

Synthesis, structural characterisation of new oligomeric alkyl aluminium (2,2′-methylene-p-chloro-bisphenoxides) and application as catalysts in polymerisation reactions involving cyclohexene oxide

“…Similarly the structural characterization of aluminium bisphenoxides bearing no ancillary sterically demanding groups at location 6 (ortho) of the bisphenoxide is scarcely documented. One single related example involving a sulfide-bridge bisphenol, 2,2 0 -thiobis {4- (1,1,3,3-tetramethylbutyl)phenol} was reported by Janas et al [17], the aluminium based-thio-bisphenoxides presenting dimeric features. An other, although remotely related, structure exhibiting an unshielded bisphenol moieties was reported by Stryker and co-workers [18].…”