THE SYNTHESIS, CHARACTERIZATION AND X-RAY CRYSTAL-STRUCTURES OF THE FAC-CIS AND MER-TRANS ISOMERS OF REOCL3(PME3)(2)

The reaction of mer-trans-ReOCl3(PPh3)(2) with PMe3 in benzene/THF aff ords an approximately equimolar mixture of the previously unreported f ac-cis-ReOCl3(PMe3)(2) (1) and mer-trans-ReOCl3(PMe3)(2) (2) as blue a nd green crystals, respectively. These isomers, which can easily be se parated, have been structurally characterized by X-ray crystallography . In the structure of 1, the Re-O distance is 1.670(5) Angstrom, while the axial Re-Cl bond (trans to Re=O) is longer (2.453(2) Angstrom) th an the two equatorial Re-Cl bonds (2.381(2) and 2.386(2) Angstrom. 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 h alf atoms Re and Re' are well resolved but the O/Cl half atoms coalesc e. (C) 1998 Elsevier Science S.A.