115775-70-7Relevant academic research and scientific papers
Substituted metal carbonyls III. Chromium, molybdenum and tungsten tricarbonyl complexes containing bipyridyl and a unidentate diphosphine: facile synthesis via trimethylamine N-oxide-induced decarbonylations
Hor, T. S. Andy,Chee, Sheh-Mai
, p. 23 - 28 (1987)
The ability of trimethylamine N-oxide as a chemical initiator for facile oxidative decarbonylation in metal carbonyls is manifested by the isolation of M(CO)3(η2-bipy)(η1-dppm) (where M = Cr, Mo, W; bipy = 2,2'-bipyridyl; dppm = bis(diphenylphosphino)-methane).The synthetic strategy and spectral (IR and 1H and 31P NMR) characterisations are presented and discussed.Syntheses of the well-known M(CO)4(η2-bipy) have also been modified to give high yields at ambient temperature.
Calorimetric studies of the heats of protonation of the dangling phosphorus in η1-Ph2PCH2PPh2 complexes of chromium, molybdenum, and tungsten
Rottink, Mary K.,Angelici, Robert J.
, p. 2421 - 2425 (2008/10/08)
Titration calorimetry has been used to determine the heats of protonation (ΔHHP) of M(CO)5(η1-dppm) (M = Cr, Mo, W) and fac-M(CO)3(Ndown curve signN)(η1-dppm) (M = Mo, Ndown curve signN = bipy, phen; M = W, Ndown curve signN = bipy) complexes with CF3SO3H in 1,2-dichloroethane solvent at 25.0°C. Spectroscopic studies show that protonation occurs at the uncoordinated phosphorus atom of the η1-coordinated dppm (Ph2PCH2PPh2) ligand. For dppm, its monoprotonated form (dppmH+), and these complexes, the basicity (ΔHHP) of the dangling phosphorus increases from -14.9 kcal/ mol to -23.1 kcal/mol in the order: dppmH+ 5(η1-dppm) 5(η1-dppm) 5(η1-dppm) 3(η2-bipy)(η1-dppm) 3(η2-phen)(η1-dppm) ≈ fac-W(CO)3(η2-bipy)(η1-dppm). In this series, H+ is more electron-withdrawing than M(CO)5 (M = Cr, Mo, W); Mo(CO)3(η2-phen) and W(CO)3(η2-bipy) actually enhance the basicity of the dangling phosphorus as compared with dppm itself. The basicity (ΔHHM) of fac-W(CO)3(η2-bipy)(PPh2Me), which protonates at the metal center to give a seven-coordinate complex, is -18.8 kcal/mol. Thus, the basicity of the dangling phosphorus atom in fac-W(CO)3(η2-bipy)(η1-dppm) is approximately 4.3 kcal/mol more basic than the metal center.
Group VI metal tricarbonyl complexes containing a unidentate diphosphine ligand II. A study of thermal behaviour of M(CO)3(η2-bpy)(η1-dppm) (M = Mo, W)
Cano, M.,Campo, J.A.,Ovejero, P.,Heras, J.V.
, p. 49 - 54 (2007/10/02)
fac-W(CO)3(η1-dppm) ( = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (dmp); dppm = bis(diphenylphosphine)methane) have been prepared in high yields by thermal reactions of W(CO)4
