96306-75-1Relevant academic research and scientific papers
Reactions of chloro complexes of dimolybdenum(II) containing quadruple metal-metal bonds with bidentate tertiary phosphines (C6H5)2P(CH2)n,P(C 6H5)2 (n = 1-3) and (C6H5)2P(CH2)2As(C 6H5)2 in alcohol media
Cole, Nancy F.,Derringer, Daniel R.,Fiore, Elizabeth A.,Knoechel, Donald J.,Schmitt, Rebecca K.,Smith, Thomas J.
, p. 1978 - 1982 (2008/10/08)
The reactions of K4Mo2Cl8 with the bidentate tertiary phosphines bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1-(diphenylphosphino)-2-(diphenylarsino)ethane (arphos), and 1,3-bis(diphenylphosphino)propane (dppp) in methanol, ethanol, and 1-propanol produce complexes of the type Mo2Cl4(LL)2. The reactions of Mo2Cl4(py)4 and Mo2Cl4(P(n-Pr)3)4 with dppe and dppp have also been explored. The only form of Mo2Cl4(dppm)2 isolated from the three alcoholic solvents is the species known to have a bridging dppm structure. In refluxing methanol both Mo2Cl84- and Mo2Cl4(py)4 yield α-Mo2Cl4(LL)2 complexes (LL = dppe, dppp), whose spectral properties are consistent with structures containing chelating phosphine ligands. In 1-propanol these reactants lead to β-Mo2Cl4(LL)2 complexes (LL = dppe, dppp), which are believed to exhibit structures with a trans disposition of donor atoms in the MoCl2P2 moiety and with the phosphine bridging the Mo2 unit. Reaction in ethanol gives rise to mixtures. Under refluxing conditions only β-Mo2Cl4(arphos)2 is produced in pure or nearly pure form from K4Mo2Cl8 and arphos, whereas in methanol at lower temperatures mixtures of α and β isomers result from reaction with (NH4)5[Mo2Cl8]Cl·H 2O. The chelating isomers are converted to the bridging forms on reflux in 1-propanol or prolonged reflux in methanol (arphos, dppp). These results indicate a thermodynamic stabilization of the β-Mo2Cl4(LL)2 species in the higher alcohols while the α isomers are the kinetically favored products in methanol. Although the reaction of Mo2Cl4(P(n-Pr)3)4 and dppe in methanol yields a mixture of α- and β-Mo2Cl4(dppe)2, the reaction with dppp produces Mo2Cl4(P(n-Pr)3)2(dppp), whose spectral properties are similar to those of the known Mo2Cl4(PR3)4 species.
