135681-24-2Relevant academic research and scientific papers
Effect of ring size on NMR parameters: Cyclic bisphosphine complexes of molybdenum, tungsten, and platinum. Bond angle dependence of metal shieldings, metal-phosphorus coupling constants, and the 31P chemical shift anisotropy in the solid state
Lindner, Ekkehard,Fawzi, Riad,Mayer, Hermann August,Eichele, Klaus,Hiller, Wolfgang
, p. 1033 - 1043 (2008/10/08)
The 31P chemical shift tensors of bis(phosphine) complexes of the type [M] [Ph2P(CH2)nPPh2] ([M] = (OC)4Mo, (OC)4W, Cl2Pt; n = 1-5) and of fac-(OC)3Mo[PPh(CH2CH2PPh2) 2] were determined by solid-state NMR techniques and correlated with structural features of the compounds. δ(31P), 1JM-P, and δ(M) show a dependence on the ring size in the solution NMR spectra of the four- to six-membered chelates; for larger rings this dependence vanishes. A model for the orientation of the 31P shift tensor principal components within the molecular frame is proposed. Each tensor component displays a different dependence on the ring size; the isotropic shift is dominated by the component perpendicular to the ring plane. Changes in this component are explained in terms of variations of the M-P-C angles. Generally speaking, the behavior of each of the tensor components must be regarded as a complex interplay of all six bond angles at phosphorus. The crystal structure of (OC)4W[Ph2P(CH2)4PPh2] (2d) was determined by X-ray diffraction. Crystals of 2d are monoclinic, space group P21/n, a = 1202.8 (1) pm, b = 1531.8 (1) pm, c = 1654.1 (2) pm, β = 104.72 (1)°, and Z = 4.
Crystal Structures of fac-tricarbonyl-chromium(0)and-molybdenum(0)
Favas, Mark C.,Kepert, David L.,Skelton, Brian W,White, Allan H.
, p. 447 - 453 (2007/10/02)
The crystal structures of the title compounds, (CO)3> , have been determined by single-crystal X-ray diffraction methods and refined to residuals of 0.055 and 0.071 for 3.653 and 4 345' observed' reflections respectively.Crystals of (1) are monoclinic, space group P21, with a=20.989(9), b=17.825(10), c=8.784(4) Angstroem, β=99.70(2) deg, and Z=4; those of (2) are monoclinic, space group P21/n, with a=15.181(7), b=18.799(4), c=12.053(4), β=106.62(3) deg, and Z=4.In both (1) and (2), the metal-central phosphorous distance is shorter than the metal-terminal phorous distances .In (1) the mean Cr-C length is 1.84 Angstroem; in (2), the mean Mo-C-length is 1.97 Angstroem.
