Metal complexes of an amine bisphenol with a thiophene side-arm

Abstract

Dedicated to Professor Bohumil Štíbr on the occasion of his 70th birthday in recognition his outstanding contributions to the field of organometallic chemistry.Dioxomolybdenum(VI) and oxotungsten(VI) complexes with a new amine bisphenol ligand (H 2 L) are reported. The ligand which carries a neutral nitrogen atom, two phenolic oxygen atoms and a thiophene side-arm was synthesized by a simple one-pot Mannich reaction. Further reaction with [MoO 2 (acac) 2 ] yielded a monomeric molybdenum complex [MoO 2 (L)(MeOH)] (2a) or a dimeric complex [Mo 2 O 2 (µ-O) 2 (L) 2 ] (2b), depending on the reaction conditions. The reaction with a tungsten trisglycolate [W(eg) 3 ] led to the formation of a monomeric compound [WO(eg)(L)] (3). In these complexes, the potentially tetradentate amine bisphenolate dianion coordinates as a tridentate O,N,O donor while the sulfur side-arm donor remains intact. The solid-state structure of 2a was investigated by X-ray crystallography.

Catalytic epoxidation using dioxidomolybdenum(VI) complexes with tridentate aminoalcohol phenol ligands

“…The overall structure is closely related to [{MoO2(L)}3] (H2L = 2,4-di-tert-butyl-6-(((2-hydroxy-2-phenylethyl)amino)methyl)phenol) reported previously by us [29]. Typically, the dioxidomolybdenum(VI) complexes with ONO-type tridentate ligands seem to complete the octahedral coordination sphere by a coordinating solvent molecule, if present, or by oxido ligand from the adjacent molybdenum complex unit to form a dinuclear oxo-bridged complex [10,40].…”