THE SYNTHESIS AND CHARACTERIZATION OF TRANS-RECL2(DPPE)(2) AND ALPHA-RE2CL4(DPPE)(2)

Two rhenium compounds, alpha-Re2Cl4(dppe)(2) and trans-ReCl2(dppe)(2), were isolated during the study of the reactivity of Re2Cl6-(P(n-Bu)(3 ))(2) with the bidentate phosphine 1,2-bis(diphenylphosphino) ethane ( dppe) in the presence of acetonitrile, and a high yield synthetic rout e was developed for alpha-Re2Cl4(dppe)(2). The structures of alpha-Re2 Cl4(dppe)(2) .(C6H6)(4), alpha-Re2Cl4(dppe)(2) .(dppe), and trans-ReCl 2(dppe)(2) . ((CH3)(2)CO)(2) were determined by X-ray crystallography and the following data obtained: alpha-Re2Cl4(dppe)(2) .(C6H6)(4), mon oclinic P2(1)/c, with a = 14.841(3), b = 12.161(4), c = 18.628(7) Angs trom, beta = 95.33(3)degrees, V = 3348(2) Angstrom(3), Z = 2, R1 = 0.0 418, and wR2 = 0.1046; alpha-Re2Cl4(dppe)(2) .(dppe), monoclinic P2(1) /c, with a = 10.695(3), b = 16.858(7), c = 19.710(7) Angstrom, beta = 101.78(1)degrees, V = 3479(2) Angstrom(3), 2=2, R1=0.0450, and wR2=0.1 023; trans-ReCl2(dppe)(2) .((CH3)(2)CO)(2), monoclinic P2(1)/c, with a =11.507(3), b=13.519(3), c = 17.243(4) Angstrom, beta = 96.08(2)degree s, V = 2667.3(11) Angstrom(3), Z = 2, R1 = 0.0369, wR2 = 0.0887. Addit ional characterizations of alpha-Re2Cl4(dppe)(2) were performed with P -31 NMR and UV-Vis spectroscopy. (C) 1998 Elsevier Science S.A.