Molecular structure of 2,2′-thiobis(4-methyl-6-tert-butylphenoxy) titanium diisopropoxy. Influence of titanium-sulfur interaction on coordination geometry

Synthesis and characterization of phosphorous-bridged bisphenoxy titanium complexes and their application to ethylene polymerization

“…The titanium-oxygen bond distances (1.822 and 1.864 Å ) are slightly shorter than those (average 1.888 Å ) observed for [Ti(tbmp)(OiPr) 2 ] 2 [19]. The angle of O(1)-Ti(1)-O(2) is 96.3°, a value which is a little larger than that observed for [Ti(tbmp)(OiPr) 2 ] 2 (92.5°) [19]. Titanium-chlorine bond distances lie in a range of 2.281-2.321 Å , and the angle of Cl(1)-Ti(1)-Cl(2) is 103.18°.…”

“…The ligand is bonded to the octahedral titanium (IV) center in a facial fashion with titanium-phosophine distance 2.620 Å , a value comparable to that found for TiCl 4 (dppe) (average 2.650 Å ) [18]. The titanium-oxygen bond distances (1.822 and 1.864 Å ) are slightly shorter than those (average 1.888 Å ) observed for [Ti(tbmp)(OiPr) 2 ] 2 [19]. The angle of O(1)-Ti(1)-O(2) is 96.3°, a value which is a little larger than that observed for [Ti(tbmp)(OiPr) 2 ] 2 (92.5°) [19].…”

“…The same treatment for the methyl ether derivative, bis(3-tertbutyl-2-methoxy-5-methylphenyl)(phenyl)phosphine (6), did not give 5a, but an unidentified mixture, which is probably due to the strong C-O bond strength of Ar-OMe (Scheme 3). Complex 5a is expected to exist as a dimer similar to thiobisphenoxy titanium complex [19]. It is notable that TiCl 4 induced the C-O cleavage and selective Ti-O bond formation when an appropriate protecting group was chosen [20].…”

Bis(amido)titanium complexes having chelating diaryloxo ligands bridged by sulfur or methylene and their catalytic behaviors for ring-opening polymerization of cyclic esters

“…In order to improve the solubility of these complexes, we studied about their bis(dialkylamido) derivatives. To the best of our knowledge, no group 4 bis(dialkylamido) complex having sulfur-or methylene-bridged bis(aryloxo) ligand has been known, while a series of their dichloro and diisopropoxo derivatives has been reported [12][13][14][15]. Here we report the synthesis and structures of the bis(dialkylamido)titanium complexes with sulfur-or methylene-bridged chelating bis(aryloxo) ligands and the catalytic behavior of these bis(amido)titanium complexes for ring-opening polymerization of e-caprolactone and L L -lactide.…”

Aryloxide-based multidentate ligands for early transition metals and f-element metals

“…A series of titanium complexes containing the [4E] 2À ligand (E = S, Se, Te, SO) could be prepared by the [32,34,35]. In contrast to the monomeric structures found for [1 tBu ]TiX 2 , [4E] 2À derivatives (E = S, Te, SO) are dimeric in the solid-state structure.…”