Synthesis of di-, tri- and penta-nuclear titanium(iv) species from reactions of titanium(iv) alkoxides with 2,2′-biphenol (H₂L¹) and 1,1′-binaphthol (H₂L²); crystal structures of [Ti₃(μ₂-OPrⁱ)₂(OPrⁱ)₈L¹], [Ti₃(OPrⁱ)₆L¹₃], [Ti₅(μ₃-O)₂(μ₂-OR)₂(OR)₆L

Abstract

Reaction of titanium(iv) alkoxides [Ti(OR)(4)](R = OPr(i), OBu(n)) with 2,2[prime or minute]-biphenol [C(12)H(8)(OH)(2), H(2)L(1)] affords two trinuclear species [Ti(3)(OPr(i))(10)L(1)] and [Ti(3)(OPr(i))(6)L(1)(3)] each possessing an open-chain V-shaped arrangement of three titanium atoms with the former having both bridging alkoxide and biphenylate groups and the latter having only biphenylate as bridging groups. Variations in reaction conditions yield the pentanuclear species [Ti(5)([micro sign](3)-O)(2)(OR)(8)L(1)(4)](R = OPr(i), OBu(n)) which have two central bridging oxygen atoms in the Ti(5) framework and bridging alkoxide and biphenylate groups. In contrast 1,1[prime or minute]-binaphthol [C(24)H(12)(OH)(2), H(2)L(2)] yields the dinuclear [Ti(2)(OPr(i))(4)L(2)(2)] where only the binaphthylate ligands act as bridging groups. Some of the compounds show catalytic activity in esterification reactions.

Polyethylene Waxes: Catalytic Synthesis by Ti‐Biphenolates

“…Depending on the molar ratio of the starting Ti(OPr i ) 4 precursor and biphenol a variety of complexes have been isolated previously by Heppert and Walsh but only a limited number of which have been characterized by X-ray crystal structure analysis (27, 28). Catalysts of the type 1 have been shown to exist as a dimer in the solid state based on X-ray analysis (29). Thus, for catalyst 1, we can envisage that the monomeric Ti(O-O)(OPr i )Cl can undergo facile…”

Two Titanium-oxo-Clusters with Malonate and Succinate Ligands: Single-Crystal Structures and Catalytic Property

“…All the bridging modes of dicarboxylate ligands in 1 and 2 are asymmetrical. The structure is similar to that of Ti 6 A photochromic effect is observed on both 1 and 2 upon UV-Vis excitation by a halogen lamp or sunlight in the presence of isopropanol. The color of the crystals is changed from transparent to gray by the light irradiation.…”

“…Great attentions have been paid on titanium-oxo-clusters (TOCs) because of their use as the model compounds of the nanoscale titanium oxide [1][2][3][4] and offering the opportunity to understand the information in terms of both atomic structure and chemical reactivity [5][6][7][8][9][10]. A large number of titanium-oxo-clusters based on Electronic supplementary material The online version of this article (doi:10.1007/s10876-015-0960-0) contains supplementary material, which is available to authorized users.…”

“…Pr)14 (BDC = benzene dicarboxylate)[15], but the l 2 -O bridge links two bipyramidal Ti atoms in this case not as Ti6 O 3 (o-BDC) 2 (O i Pr)14 , in which the l 2 -O bridge links one octahedral Ti atom and one bipyramidal Ti atom. The Ti2-O21-Ti4 angle of l 2 -O bridge in 1 is 160.3°, and the Ti1-O16-Ti2 angle of l 2 -O bridge in 2 is 158.1°that is smaller than the former.…”

Miniature high-throughput chemosensing of yield, ee, and absolute configuration from crude reaction mixtures

“…2F , we obtained a linear CD response to the substrate ee at two distinct wavelengths, which is in contrast to the chiroptical NLE of the zinc complex described above. Although the linear CD effect could be attributed to a monomeric metal complex ( 39 ), it is known that diphenolate- and binaphtholate-derived titanium complexes typically form μ-oxo–bridged dinuclear structures and often exhibit dynamic equilibria of higher aggregates ( 40 ). We observed only a signal of ternary ( 1 -Ti- 25 ) 2 by ESI-MS and detected no sign of the mononuclear analog, higher aggregates, and binary Ti complexes carrying either only 1 or 25 (see the Supplementary Materials).…”