Oxalate Complexes of Titanium Supported by a Tris(phenolato)‐Amine Ligand

A bridging oxalate complex of titanium(IV) supported by a tris(phenolato)‐amine ligand [{(O 3 N)Ti} 2 (μ‐C 2 O 4 ‐κO 2 :κO″ 2 )] ( 2 , H 3 (O 3 N) = tris(4,6‐di‐ tert ‐butyl‐2‐hydroxybenzyl)amine) is obtained by the protonolysis of the benzyl complex [(O 3 N)Ti(CH 2 Ph)] ( 1‐Bn ) or by the oxidation of the titanium(III) complex [(O 3 N)Ti)] 2 ( 1 2 ) using oxalic acid. Reduction of the oxalate complex 2 with potassium gives the titanium(III) complex [K(toluene) 2 ][(O 3 N)Ti(μ‐C 2 O 4 ‐κO 2 :κO″ 2 )Ti(O 3 N)] ( 3 ). Protonolysis with [NEt 3 H]Cl leads to a 1:1 mixture of [NEt 3 H][(O 3 N)Ti(OCOCOO‐κO 2 :κO″ 2 ))] ( 4 ) and [(O 3 N)TiCl] ( 1‐Cl ). The mono‐ tert ‐butyl oxalate complex [(O 3 N)Ti(OCOCOO t Bu‐κO 2 :κO″ 2 )] ( 5 ) is formed by the reaction of the titanium(III) complex [(O 3 N)Ti)] 2 ( 1 2 ) with di‐ tert ‐butyl oxalate. Single‐crystal X‐ray diffraction of complexes 2 , 3 , and 5 shows a distorted octahedral coordination at the titanium center in all three complexes.