Photochemical reactions of Re(CO)5Br with Ph2P(CH2)nPPh2 (n = 1, dppm; 2, dppe; 3, dppp)

The new complexes fac-[Re(CO)3Br{Ph2P(CH2) n PPh2}] (1a–3a) [(1a), n = 1; (2a), n = 2; (3a), n = 3] and [Re2(CO)8Br2{μ-Ph2P(CH2) n PPh2}] (1b–3b) [(1b), n = 1; (2b), n = 2; (3b), n = 3] have been prepared by the photochemical reaction of Re(CO)5Br with Ph2P(CH2) n PPh2 (n = 1, dppm; 2, dppe; 3, dppp). The complexes have been characterized by elemental analysis, mass spectroscopy, f.t.-i.r. and 31P-[1H]-n.m.r. spectrometry. The spectroscopic studies suggest cis-chelate bidentate coordination of the ligand in fac-[Re(CO)3Br{Ph2P(CH2) n PPh2}] (1a–3a) and cis-bridging bidentate coordination of the ligand between two metals in [Re2(CO)8Br2{cis-μ-Ph2P(CH2) n PPh2}] (1a–3a).