The synthesis, characterization and X-ray crystal structures of the fac-cis and mer-trans isomers of ReOCl 3(PMe 3) 2

Abstract

The reaction of mer-trans-ReOCl 3(PPh 3) 2 with PMe 3 in benzene/THF affords an approximately equimolar mixture of the previously unreported fac-cis-ReOCl 3) 2 ( 1) and mer-trans-ReOCl 3(PMe 3) 2 ( 2) as blue and green crystals, respectively. These isomers, which can easily be separated, have been structurally characterized by X-ray crystallography. In the structure of 1, the ReO distance is 1.670(5) Å, while the axial ReCl bond ( trans to ReO) is longer (2.453(2) Å) than the two equatorial ReCl bonds (2.381(2) and 2.386(2) Å). The structure of 2 is complicated by an orientation disorder in which the OReCl unit is arranged in two opposite orientations such that the half atoms Re and Re′ are well resolved but the O/Cl half atoms coalesce.