Synthesis of Titanatranes Containing Bis(aryloxo)‐(alkoxo)amines and their Use in Catalysis for Ethylene Polymerization

Abstract

2 )]N} (1c) showed higher activity than 1a under the same conditions. Ti{[(O-2,4-Me 2 C 6 H 2 -6-CH 2 ) 2 (HOCH 2 CH 2 CH 2 )]N} 2 was isolated from the reaction of Ti(O i Pr) 4 with bis(2-hydroxy-3,5-dimethylbenzyl)-propanolamine; the structure was determined by X-ray crystallography.

Synthesis and Structural Analysis of Titanatranes Bearing Terminal Substituted Aryloxo Ligands of the type [Ti(OAr){(O-2,4-Me2C6H2-6-CH2)2(OCH2CH2)N}]n (n = 1, 2): Effect of Aryloxo Substituents in the Ethylene Polymerization

“…There has been immense research interest in designing various metal complexes containing tripodal trianionic donor (called “atrane”) ligands, such as tris(amido)amine, tris(alkoxo)amine, and tris(aryloxo)amine. − These trianionic donor ligands, usually bind to a transition metal in a tetradentate manner and are capable of providing a range of stable steric and electronic environments for (catalytically active) metal centers. The perfect combination consisting of the exocylic axial group and a flexible transannular bond between an axial nitrogen atom (of the tripodal ligand) and a metal ion generates a pseudo 3-fold symmetric environment (like a specific pocket around the metal center) .…”

“…There have been many reports for synthesis, structural analysis, and some reactions not only of main group atranes (silatranes, phosphatranes, etc. ) − , but also of the transition metal complexes containing atrane ligands, ,,,− especially titanatranes. ,,,,− Some successful examples, such as applications as catalysts for organic synthesis by titanatranes , and the catalytic dinitrogen activation by molybdenum complexes, were well-known. Moreover, applications using titanatranes as the catalyst precursors for syndiospecific styrene polymerization , and lactide polymerization were known.…”

“…The above-mentioned results , prompted us to synthesize a series of titanatranes containing substituted aryloxo terminal ligands as the catalyst precursors for the olefin polymerization. Although considerable attention has been paid to modification of the atrane framework (e.g., variable ring size), however, detailed studies for synthesis and structural analysis for the titanatranes (bearing uniform ring size) containing various substituents on the aryloxo terminal ligand, including the effect of substituents on the aryloxo terminal ligands toward the crystal structures (monomeric/dimeric etc.)…”

Synthesis, Structural Characterization of Substituted Phenoxyimine Based Ti(IV) Complexes for Ring Opening Polymerization and DFT Studies

“…[19][20][21][22][23][24][25] Among the five possible isomers (Figure 1), the crystallographically determined structures of FI catalysts, with a few exceptions, [26][27][28][29][30][31] adopt a configuration in which the shortest MÀ O bonds for group 4 transition metals are positioned trans to each other, and the nitrogen atoms and X ligands are in cispositions, displaying overall C 2 symmetry (Figure 1). [32][33][34] The two imine-N's are positioned in a plane that is defined by a metal M and two X ligands in this typical C 2 symmetric FI catalyst. While, ortho to the phenoxy -(R 2 ) O's are placed above and below the XÀ MÀ X moiety, substituents on the imine-(R 1 ) N's are on a plane at the backside of the XÀ MÀ X moiety.…”

Dichiral [4.4.3.01,5]tridecane copper(II) cluster derived from a tripodal ligand having unsymmetrical podands and the linker: Synthesis, structure, surface grafting and catalytic aspects

“…The [4.4.3.0 1,5 ]tridecane metal cages are continuously achieving interest due to their fascinating structural attributes and relevance in catalysis. [1][2][3][4][5][6] These are named as 'pseudo-atranes' due to their structural analogy with metallatranes. The pseudo-atranes with [4.4.3.0 1,5 ] tridecane cage differ from the atranes (having [3.3.3.0 1,5 ] undecane metal cages) in terms of the number or composition of the tricyclic ring atoms.…”