70505-43-0Relevant articles and documents
Synthesis, spectroscopic and structural characterisation of chromium(0), molybdenum(0) and tungsten(0) complexes involving primary and secondary phosphines
Campbell, Tom,Gibson, Alexander M.,Hart, Richard,Orchard, Simon D.,Pope, Simon J.A.,Reid, Gillian
, p. 296 - 305 (2007/10/03)
[M(CO)6] (M=Mo or W) reacts with 4.5 molar equivalents of L (L=PPh2H or PPhH2) in excess ethanolic NaBH4 to yield the fac-trisubstituted species [M(CO)3(L)3] in good yield, with no evidence
Reactions Leading to Formation and Cleavage of Metal-Metal and Metal-μ-Phosphido Bonds in Binuclear Molybdenum and Tungsten Complexes. Structural Analyses of W2(CO)8(μ-PPh2)2 and Its Two-Electron Reduction Product, 2
Shyu, Shin-Guang,Calligaris, Mario,Nardin, Giorgio,Wojcicki, Andrew
, p. 3617 - 3625 (2007/10/02)
Reduction of M2(CO)8(μ-PPh2)2 (M= Mo (1-Mo) or W (1-W)) and reactions of various binuclear molybdenumand tungsten anionic products were found generally to proceed with a remarkably facile scission or formation of M-M and M-(μ-PPh2) bonds.Thus, complexes 1 are converted by M'BR3H (M'= Li, R= Et; M'= K, R= sec-Bu) or LiAlH4 in THF to the M-M bond cleaved 2- (2) or to (3) depending on the nature and, usually the amount of the reductant.Reactions of 1 with LiR (R= Me (a), N-B (b), Ph (c)) afford the acyl anions (4a-c), of which yield the carbene complexes (5a,c) when treated with Me3OBF4.The M-M bond of 3 is readily broken by CO and n-BuLi to give - (6) and 2, respectively.Treatment of 3 with CF3COOH leads to a fragmentation of the binuclear unit with the formation of cis-M(CO)4(PPh2H)2 and M(CO)5(PPh2H).The dianions 2 are converted to the M-M bonded 3 and 4a when reacted with 1 equiv of CF3COOH and MeI (in THF or DMF), respectively.Possible mechanisms of these reactions are discussed.The structures of 1-W and its 2-electron reduction product,Li(THF)3+>22-W, were determined by single-crystal X-ray diffraction analyses.Both crystals are monoclinic of space group P21/c, with a= 9.830 (2) Angstroem, b= 19.802 (4) Angstroem, c= 16.889 (5) Angstroem, β= 103.72 deg, and Z= 4 for 1-W and a= 11.265 (5) Angstroem, b= 19.546 (3) Angstroem, c= 16.446 (5) Angstroem, β= 122.07 (3) deg, and Z= 2 for +>22-W.The structure of 1-W was solved and refined to R= 0.030 and RW= 0.33 by using 5206 independent reflections, whereas the structure of +>22-W was solved and refined to R= 0.051 and RW= 0.062 by using 3987 independent reflections.Both structures possess a planar W2P2 core.The W-W distance of 3.0256 (4) Angstroem in 1-W increases to a nonbonding value of 4.1018 (4) Angstroem in 2-W, and the W-P-W bond angles of 75.14 deg (mean) in 1-W widen to 104.20 deg in 2-W.The Li+ ion in +>22-W possesses an almost regular tetrahedral oxygen environment, being attached to three THF molecules and an equatorial CO of 2-W.
Reactions of M2(CO)8(μ-PPh2)2 (M = Mo or W) with BR3H- and LIR nucleophiles. Proton-induced cleavage of M-(μ-PPh2) bonds in binuclear anionic complexes
Shyu, Shin-Guang,Wojcicki, Andrew
, p. 809 - 812 (2008/10/08)
Reactions of M2(CO)8(μ-PPh2)2 (2, M = Mo or W) with 1 equiv of M′BR3H (M′ = Li or K; R = Et or sec-Bu) in THF proceed to [(CO)4M(μ-PPh2)M(CO)4-Scheme I (Chemical Equation Presented) (PPh2H)]- (3) and with 2 equiv of M′BR3H or LiAlH4, to [M2(CO)8(μ-PPh2)2]2- (4). Treatment of 4 with 1 equiv of CF3COOH in THF affords 3, whereas treatment of 3 with 1 equiv of CF3COOH yields cis -M(CO)4(PPh2H)2 and M-(CO)5(PPh2H) as major and minor products, respectively. Reactions of 2 with LiR (R = Me, n-Bu, and Ph) proceed regiospecifically to the equatorial isomers of [M2(CO)7-(COR)(μ-PPh2)2] -, which are alkylated by Me3O+BF4- to yield M2(CO)7[C(OMe)R] (μ-PPh2)2 (R = Me).
