56054-39-8Relevant academic research and scientific papers
High-yield synthesis of Mo(η6-PhPMe2)(PMe2Ph)3 and its dimerization to form {Mo(μ-η1,η6-PMe2Ph) (PMe2Ph)2}2, a complex characterized by X-ray crystallography
Cotton, F. Albert,Luck, Rudy L.,Morris, Robert H.
, p. 1282 - 1287 (2008/10/08)
The reduction of Mo2Cl10 with Mg in THF in the presence of PMe2Ph at 70°C yields the η6-bonded arylphosphine complex Mo(η6-PhPMe2)(PMe2Ph)3 in high yields. This complex does not undergo substitution reactions with CO and P(OMe)3 at ca. 25°C. A substitution reaction occurs with 1 mol of P(OMe)3 at 45°C to form the monosubstituted derivative Mo(η6-PhPMe2)(PMe2Ph) 2(P(OMe)3). The reaction of Mo(η6-PhPMe2)(PMe2Ph)3 with 1/2[RhCl(COD)]2 (COD = 1,5-cyclooctadiene) initially results in the bimetallic complex Mo(η6-PhP(RhCl(COD)}Me2)(PMe2Ph) 3. The dinuclear complex [Mo(μ-η1, η6-PMe2Ph)(PMe2Ph)2]2 is obtained in the reaction of Mo(η6-PhPMe2)(PMe2Ph)3 and ReH7(PPh3)2. The structural assignments are based on 1H and 31P{1H} NMR spectra, elemental analysis, and in the case of the dimer a single-crystal X-ray structural determination. The cyclic voltammograms for Mo(η6-PhPMe2)(PMe2Ph)3 and some analogues are also reported. The dimer crystallizes in the monoclinic space group P21/c with cell dimensions a = 11.699 (2) A?, b = 12.117 (1) A?, c = 16.352 (2) A?, β= 93.1 (1)°, V = 2314.6 (7) A?3, and Dcalcd = 1.465 g/cm3 for Z = 2. The structure was solved by a three-dimensional Patterson map and refined by least-squares and Fourier methods to final residuals R = 0.031 (Rw = 0.039) for 3299 observed (Fo2 > 3σ(Fo)2) reflections. The geometry about the molybdenum is distorted octahedral. Averaged principal bond lengths are Mo-C(ring) = 2.27 [1] and Mo-P = 2.433 [2] A?, and the Mo-Mo distance is 4.9706 (3) A?.
Complexes containing unbridged homonuclear or heteronuclear quadruple bonds. Crystal and molecular structures of MoWCl4(PMePh2)4, MoWCl4(PMe3)4, and Cl2(PMe3)2MoWCl2(PMePh 2)2
Luck, Rudy L.,Morris, Robert H.,Sawyer, Jeffery F.
, p. 2422 - 2429 (2008/10/08)
The reactions of Mo(η6-PhPMePh)(PMePh2)3 and Mo(η6-PhPMe2)(PMe2Ph)3 with MoCl4(THF)2 yield the homonuclear unbridged quadruply bonded complexes Mo2Cl4(PR3)4 (PR3 = PMePh2 (1), PMe2Ph (2)). Complex 1 readily undergoes phosphine substitution with PMe3 to yield Mo2Cl4(PMe3)4 (3). The reactions of Mo(η6-PhPMe2)(PMe2Ph)3 and Mo(η6-PhPMePh)(PMePh2)3 with WCl4(PPh3)2 yield the complexes MoWCl4(PR3)4 (PR3 = PMe2Ph (4), PMePh2 (5)), which are among the first to contain an unbridged quadruple bond between two different elements. Complex 5 undergoes phosphine substitution reactions with PMe3 to give sequentially Cl2(PMe3)2MoWCl2(PMePh 2)2 (6) and then MoWCl4(PMe3)4 (7). Complex 4 can also be synthesized by reacting 5 with PMe2Ph. The 31P and 1H NMR spectra, electronic and visible spectra, and cyclic voltammograms of these complexes are interpreted, and the crystal and molecular structures of 5-7 are reported. Compounds 5 and 7 were found to have disordered arrangements of the metal atoms; compound 6 with the different phosphine ligands on the metal atoms is, however, ordered with a Mo4-W bond length of 2.207 (1) A?. In 6 and 7 the molecules have crystallographic 2-fold symmetry. In all three structures the ligand arrangement over the metal-metal bond defines an eclipsed geometry with chlorine next to phosphine across the bond in a pseudo-D2d arrangement. The metal-metal distances in 5 and 7 are 2.208 (4) (average) and 2.2092 (7) A?, respectively. These values are close to distances expected on the basis of homonuclear M4-M bonds, and therefore there is no extra shortening of these bonds due to electronegativity differences. Crystal data: 5, monoclinic, space group P21/a, a = 21.511 (4) A?, b = 12.176 (6) A?, c = 40.863 (8) A?, β = 92.65(2)°, V = 10692 A?3, Dcalcd = 1.52 g cm-3 for Z = 8, R = 0.0957 for 3554 observed (I > 3σ(I)) reflections; 6, monoclinic, space group I2/a, a = 16.817 (4) A?, b = 11.925 (3) A?, c = 19.685 (5) A?, β = 103.87 (2)°, V = 3832.4 A?3, Dcalcd = 1.69 g cm-3 for Z = 4, R = 0.0364 for 2203 observed reflections; 7, monoclinic, space group I2/a, a = 17.312 (4) A?, b = 9.193 (1) A?, c = 19.085 (3) A?, β = 119.69 (2)°, V = 2638.9 A?3, Dcalcd = 1.57 g cm-3 for Z = 4, R = 0.0312 for 2084 observed reflections.
