98776-40-0Relevant academic research and scientific papers
Thermolysis of Re2(CO)10-n(P(C6H5)3)n (n = 1, 2)
Haupt, Hans-J.,Balsaa,Fl?rke
, p. 280 - 286 (2008/10/08)
Heating Re2(CO)8(ax-L)2 (1) [L = P(C6H5)3] in xylene solution in a sealed glass tube at 180-230°C gives six products of two types: first, Re2(CO)8-nLn(μ-H)(μ-P(C6H 5)2) (n = 1, eq-L, 2; n = 2, eq-L, 3); second, (C6H5)2PC6H 3(C=O)Re(CO)4-mLmRe-(CO)4-nL n (m = 1, ax-L, n = 0, 4; m = n = 1, ax-L, 5; m = 1, eq-L, n = 1, ax-L, 6; m = 0, n = 2, ax-L, 7). At 160°C only 2 and 3 are observed. The complex Re2(CO)8(μ-H)(μ-P(C6H5) 2) (8) is obtained by thermolysis of Re2(CO)9(ax-L) (9) in xylene solution at 180°C. Thermolysis of 2 in decalin solution at 240°C leads to Re3(CO)9(μ-P(C6H5) 2)3 (10). 1H and 31P NMR data have been measured for the newly synthesized compounds. The molecular structures of 2, 4, and 10 have been determined from X-ray data collected on an automated diffractometer with monochromatized Mo Kα radiation. Compounds 2 and 4 crystallize in the monoclinic space group P21/n (No. 14), and 10 crystallizes in P21/a (No. 14), with Z = 4: 2, a = 13.431 (9) A?, b = 11.804 (5) A?, c = 23.072 (12) A?, β = 102.78 (6)°; 4, a = 16.800 (2) A?, b = 12.077 (3) A?, c = 23.048 (3) A?, β = 92.82 (1)°; 10, a = 11.670 (3) A?, b = 23.151 (14) A?, c = 16.327 (3) A?, β = 90.08 (3)°. The molecular structure of the diamagnetic compound 2 contains two octahedrally coordinated rhenium atoms with a hydrido- and diphenylphosphido-bridged Re-Re bond (Re-Re = 3.152 (1) A?). The μ-H position could not be evaluated from a Fourier map. Therefore, the presence of the monohydride compound was shown by the results of 1H high-field NMR measurements. The eq-L ligand in 2 is trans-positioned to the μ-P(C6H5)2 group. The molecular structure of the secondary metalation product 4 possesses two rhenium atoms, each with an essentially octahedral arrangement of the ligands. One rhenium atom is coordinated by four carbonyl groups while the other is coordinated by three carbonyl groups and a triphenylphosphine. The two rhenium atoms are bridged by a quadridentate ligand that is bidentate to each metal atom. The molecule has an extended planar tricyclic ring system that includes the bridging ligand and both metal atoms. A comparison of its bond parameters with those of related rhenium and manganese compounds is given. The molecular structure of 10 shows as a central fragment a three-membered ring of rhenium atoms [average Re-Re = 2.914 (4) A?] edged-bridged by diphenylphosphido groups. Each rhenium coordination sphere contains, besides the two trans-positioned μ-P ligand atoms, three additional CO groups having a meridional ligand arrangement.
