Organometallic Mo–O–Bi complexes

Abstract

The reaction between Ph 3BiBr 2 and wet [NBu 4] 2[MoO 4] leads to a white solid that according to Klemperer and Liu analyses as [NBu 4] 2[BiPh 3(MoO 4) 2] · 3H 2O ( 1 aq ). Working under strictly anhydrous conditions allowed us the isolation of the solvate-free complex [NBu 4] 2[BiPh 3(MoO 4) 2] ( 1), which in contrast to 1 aq could also be characterised by means of single crystal X-ray diffraction. The results reveal a structure with a Bi V ion being surrounded by three phenyl substituents and two molybdate units. Remarkably the resulting two Mo VI–O–Bi V linkages are linear and according to a DFT investigation this is due to a predominantly ionic interaction between the O and Bi atoms. Moreover a novel Mo VI–O–Bi III complex, NBu 4[{Cp∗Mo(O) 2-μ-O-} 2(Bi( o-tolyl) 2)] ( 2), has been prepared via reaction of the coordination polymer [(Cp∗Mo(O) 2)-μ-O-(Bi( o-tolyl) 2)] n with [NBu 4][Cp∗MoO 3] and the crystal structure of 2 has been investigated. According to DFT results the character of the bonds within the bent Mo–O–Bi unit is described most appropriately as covalent. The structure of 2 is discussed also with respect to corresponding Mo–O–Bi moieties occurring in bismuthmolybdate catalysts, for which it could represent a molecular structural model.