Synthesis of Titanium Complexes Containing an Amine Triphenolate Ligand of the Type [TiX{(O-2,4‑R<sub>2</sub>C<sub>6</sub>H<sub>2</sub>)‑6-CH<sub>2</sub>}<sub>3</sub>N] and the Ti–Al Heterobimetallic Complexes with AlMe<sub>3</sub>: Effect of a Terminal Donor Ligand in Ethylene Polymerization

The synthesis of various titanatranes containing tris­(aryloxo)­amine ligands, TiX­[{(O-2,4-R<sub>2</sub>C<sub>6</sub>H<sub>2</sub>)-6-CH<sub>2</sub>}<sub>3</sub>N] [R = Me (<b>1</b>), <sup><i>t</i></sup>Bu (<b>2</b>); X = O<sup><i>i</i></sup>Pr (<b>a</b>), O<sup><i>t</i></sup>Bu (<b>b</b>), OCH­(CF<sub>3</sub>)<sub>2</sub> (<b>c</b>), OC­(CF<sub>3</sub>)<sub>3</sub> (<b>d</b>), Cl (<b>e</b>)], and some reactions with Al alkyls have been explored. The Ti–Al heterobimetallic complexes [TiMe­{(O-2,4-Me<sub>2</sub>C<sub>6</sub>H<sub>2</sub>-6-CH<sub>2</sub>)<sub>2</sub>­(μ<sub>2</sub>-O-2,4-Me<sub>2</sub>-C<sub>6</sub>H<sub>2</sub>-6-CH<sub>2</sub>)}­N]-[Me<sub>2</sub>Al­(μ<sub>2</sub>-OR′)] [R′ = <sup><i>t</i></sup>Bu (<b>3b</b>), CH­(CF<sub>3</sub>)<sub>2</sub> (<b>3c</b>), C­(CF<sub>3</sub>)<sub>3</sub> (<b>3d</b>)] were isolated by reaction of <b>1b</b>–<b>d</b> with 1 equiv of AlMe<sub>3</sub>, whereas reaction of <b>2b</b> with AlMe<sub>3</sub> in toluene did not take place under the same conditions, and the reaction of <b>2c</b> afforded the methyl complex TiMe­[{(O-2,4-<sup><i>t</i></sup>Bu<sub>2</sub>C<sub>6</sub>H<sub>2</sub>)-6-CH<sub>2</sub>}<sub>3</sub>N]. Structures of <b>3b</b>,<b>c</b> were determined by X-ray crystallography. These complexes exhibited high catalytic activities for ethylene polymerization in <i>n</i>-octane in the presence of MAO, and the activity by <b>1</b> and <b>2</b> was affected by the terminal donor ligand (X) as well as the substituent on the atrane ligand (R). The activities by <b>1c</b>,<b>d</b> increased upon addition of AlMe<sub>3</sub>, and the corresponding heterobimetallic complexes (<b>3c</b>,<b>d</b>) showed high activities, whereas an increase in the activity upon addition of AlMe<sub>3</sub> was not observed by <b>1b</b>,<b>e</b>, and <b>2c</b>,<b>e</b>.