A cis-dibromorhenium(V) iminophenolato complex

The complex cis-[ReOBr2(msa)(PPh3)](1) was prepared from trans-[ReOBr3(PPh3)2] and 2-(1-iminoethyl)phenol (Hmsa) in acetonitrile. An X-ray crystallographic study shows that the two bromides are coordinated cis to each other in the equatorial plane cis to the oxo group. DFT calculations on 1 and its trans isomer show that the energy difference between the HOMO and LUMO in the cis isomer is smaller than that in the trans.