148353-91-7Relevant academic research and scientific papers
Studies of a reluctant ligand. An X-ray crystallographic and NMR spectroscopic analysis of (OC)5W(η1-PPh2CH2PPh 2) and Its (OC)5W(μ-PPh2CH2PPh2)W(CO) 5 derivative
Benson, John William,Keiter, Richard L.,Keiter, Ellen A.,Rheingold, Arnold L.,Yap, Glenn P. A.,Mainz, Vera V.
, p. 4275 - 4281 (1998)
Tungsten pentacarbonyl complexes, (OC)5W(η1-PPh2CH2PPh 2) (1) and (OC)5W(μ-PPh2CH2PPh2)W(CO) 5 (2), have been synthesized from (OC)5WNH2Ph and Ph2PCH2PPh2 in toluene, and their solid-state structures have been determined by single-crystal X-ray diffraction. The lone pair of electrons on the dangling phosphine in 1 is oriented toward the W(CO)5 unit in the solid state, and 13C{1H} and 31P{1H} NMR data suggest that this conformation may also be dominant in solution. Phosphorus-phosphorus coupling in 1 (2JPP = 106 Hz) is significantly larger than in any previously reported complex of Ph2PCH2PPh2 and is highly dependent on changes in temperature and solvent. Also observed is an unprecedented long-range phosphorus-carbon coupling (4Jpc = 3.0 Hz) between the dangling phosphine and the equatorial carbonyl carbons of 1, which is attributed to a conformational and/or through-space enhancement. On the basis of the structural and spectral data, the reluctance of 1 to react with (OC)5WNH2Ph to give 2 is explained in terms of the substantial ligand conformation change required.
On the synthesis and 31P NMR spectrum of (CO)5W(μ-PPh2CH2PPh2)W(CO)5
Benson, J. W.,Keiter, E. A.,Keiter, R. L.
, p. 77 - 82 (1995)
The dimetallic complex, (CO)5W(μ-PPh2CH2PPh2)W(CO)5, is synthesized from either a 2:1 mixture of (CO)5W(NCMe) and (CO)5W(η1-PPh2CH2PPh2) or a 3:1 mixture of (CO)5W(NCMe) and PPh2CH2PPh2 in toluene at 60 deg C.The coupling constants, 2JPP' = 22.9 Hz, 1JWP = 246.9 Hz and 3JWP' = 4.5 Hz are consistent with those reported in the literature for similar complexes.The complex (CO)5W(η1-PPh2CH2PPh2) is stable with respect to chelation at room temperature. Keywords: Tungsten; Bis(diphneylphosphino)methane; P-31 NMR; Ditertiary phosphines; Coupling constants; Carbonyl
-bis Complexes of the Group 6B Elements: Synthesis and Spectroscopic Study
Oezer, Zahide,Oezkar, Saim,Pamuk, H. Oe.
, p. 37 - 43 (2007/10/02)
-bis complexes (CO)5MR2P(CH2)nPR2M(CO)5, (M: Cr, Mo, W; n: 1,2,3; R: CH3, C2H5, C6H5) were synthesized from the reaction of M(CO)5(CH3CN) with the appropriate ligand and characterized by means of IR and NMR (1H, 13C, 31P) spectroscopy.Spectral data indicate that the complexes contain two identical M(CO)5 moieties linked to each other by the R2P(CH2)nPR2 ligand.Each metal atom has a pseudo-octahedral arrangement of the five CO ligands and one phosphorus atom.Keywords: Chromium, Molybdenum, Tungsten, Dinuclear Complexes, Diphosphine
