105502-46-3Relevant academic research and scientific papers
Mixed chloride/amine complexes of dimolybdenum(II,II). 2. Reactions of Mo2Cl4(NHEt2)4 with monodentate and bidentate phosphines. New type of compounds Mo2Cl4(diphosphine)4
Cotton, F. Albert,Dikarev, Evgeny V.,Herrero, Santiago
, p. 490 - 495 (2008/10/08)
The complex Mo2Cl4(NHEt2)4 (1) undergoes facile substitution reactions of the amine ligands by phosphines to give compounds with the same core structure, Mo2Cl4(phosphine)4, where the phosphine is PMe3 (2), PMe2Ph (3), PHEt2 (4), dmpm (bis(dimethylphosphino)methane) (5), or dmpe (l,2-bis(dimethylphosphino)ethane) (6). Complexes of the type M2X4L4 are well-known with monodentate ligands, but there is no previous crystallographically verified example of the M2X4L4 type of compound in which L is a potentially bidentate ligand acting as a unidentate ligand. Mo2Cl4(η1-dmpm)4 (5) can be isolated in good yield as the kinetic product of the substitution reaction at room temperature. When a solution of 5 in THF is heated, transformation into the more stable compound Mo2Cl4(μ-dmpm)2 (7) takes place. Mo2Cl4(η1-dmpe)4 (6) is stable in solution in the presence of free phosphine and can be detected by NMR. Over time it converts to a polymeric material which precipitates from the solution. For dppm (bis(diphenylphosphino)methane) (8) and dppa (bis(diphenylphosphino)amine) (9), only products of the stoichiometry Mo2Cl4(diphosphine)2 were obtained. The crystal structures of the complexes 4 and 5 have been investigated by X-ray diffraction. The crystallographic parameters for them are as follows: for 4, orthorhombic space group Pbcn with a = 7. 6015(8) A, b = 20.120(8) A, c = 19.070(6) A, and Z = 4; for 5, hexagonal space group P6422 with a = 12.396(1) A, c = 21.960(2) A, and Z = 3. Both structures have a Mo2Cl4P4 core where the phosphorus atoms are trans one to another on each metal center. The Mo-Mo distances of 2.137(1) A (4) and 2.137(1) A (5) are consistent with quadruple bonding.
Quadruply bonded dimolybdenum complexes containing pairs of bridging diphosphine and acetate ligands; synthesis and structural characterization of trans-Mo2Cl2(OAc)2(μ-dppa)2 and its transformation to Mo2Cl4(μ-dppa)2, where dppa is N,N-bis(diphenylphosphino)amine
Wu, Ying-Yann,Chen, Jhy-Der,Liou, Lin-Shu,Wang, Ju-Chun
, p. 193 - 200 (2008/10/08)
By reaction of Mo2(OAc)4 with (CH3)3SiCl and dppa (dppa = Ph2PN(H)PPh2) in THF, two complexes can be prepared. The red complex trans-Mo2Cl2(OAc)2(μ-dppa)2 (1) was obtained in 42% yield while the green complex Mo2Cl4(μ-dppa)2 (2) was prepared in 31% yield. Complex 2 can also be derived by reacting K4Mo2Cl8 or Mo2Cl4(PPh3)2(CH3OH)2 with dppa in methanol and acetone, respectively. Reaction of 1 with (CH3)3SiCl leads to the formation of 2. Their UV-Vis and (31)P{(1)H} NMR spectra have been recorded and the structures of both 1 and 2 have been determined. Crystal data for 1: space group Pbca, a = 16.699(1), b = 16.784(1), c = 19.728(2)?, V = 5529.3(7)?**3, Z = 4, with final residuals R = 0.0606 and Rw = 0.0620. The diphosphine ligands are bridged to the metal centers with an eclipsed configuration around the metal-metal bond. The chloride atoms are forced to coordinate to the Mo atoms in the axial positions. Crystal data for 2: space group Ibca, a = 16.165(2)?, b = 16.576(2)?,c = 37.024(3)?, V = 9921(2)?**3, Z = 8, with final residuals R = 0.0933 and Rw = 0.0990. The two dppa ligands are bridged to the metal centers. The interconversions between 1 and 2 are discussed.
Preparation and Characterization of Bis[dihalo(μ-bis(diphenylphosphino)amine)molybdenum(II)] Complexes
Arnold, Delrdre I.,Cotton, F. Albert,Kühn, Fritz E.
, p. 5764 - 5769 (2008/10/09)
Complexes having the formula Mo2X4-dppa)2 (X = Cl (2) Br (3); dppa = bis(diphenylphosphino)amine) can be synthesized by the reaction of Mo2(OAc)4 (OAc = μ-CH3COO) with dppa and an excess of (CH3 )3SiX under reflux conditions. Both compounds were characterized by IR and UV/vis spectroscopy and by 31P{1H} and 1H NMR spectroscopy. Single-crystal diffraction studies afford the following pertinent crystal data for 2 and 3, respectively: monoclinic P21/c, a = 15.522(4) A?, b = 17.881(5) A?, c = 16.898(3) A?, β= 91.15(2)°, Z = 4; orthorhombic P212121, a = 19.654(2), b = 19.865(2) c = 14.792(1), Z = 4. Both compounds exhibit significant torsion angles but, nevertheless, have comparatively short Mo-Mo bond distances (2, d(Mo-Mo) = 2.134(1) A?; 3, d(Mo-Mo) = 2.137(2) A?).
