14154-60-0Relevant academic research and scientific papers
Reactions of metal-metal multiple bonds. 11. A comparison of the reactivity of M2(OR)6 (M≡M) and M2(OR)4(R′COCHCOR′)2 (M≡M) compounds (M = Mo, W) with the π-acid ligands CO, RC≡CR, and RNC
Chisholm, Malcolm H.,Corning, James F.,Folting, Kirsten,Huffman, John C.,Ratermann, Andrew L.,Rothwell, Ian P.,Streib, William E.
, p. 1037 - 1042 (2008/10/08)
M2(OR)6 compounds (M = Mo, W; R = t-Bu, i-Pr, CH2-t-Bu) react in hydrocarbon solvents with isocyanide ligands to give, upon workup with methanol and KPF6, M(CN-alkyl)72+ salts or M(CNPh)6 compounds in a similar manner, noted by Walton and co-workers for reactions involving M-M quadruply bonded compounds. By contrast, Mo2(OR)4-(R′COCHCOR′)2 compounds (R′ = Me, t-Bu) react in hydrocarbon solvents to give edge-shared (μ-OR) octahedral complexes and provide the first examples of the conversion of L4M≡ML4 compounds to L4M(μ-L)2ML4 compounds. These are also the first reactions wherein a multiple bond between molybdenum atoms is not cleaved by isocyanide ligands. The compound Mo2(OCH2-t-Bu)4(MeCOCHCOMe) 2(t-BuNC)2 has been fully characterized by an X-ray study. Cell dimensions at -163 °C are a = 13.817 (5) A?, b = 12.518 (4) A?, c = 14.045 (5) A?, and β = 92.61 (2)° with Z = 2 in the space group P21/n. The conversion of an unbridged triple bond σ2π4 to an edge-bridged d3-d3 dimer of formal M-M configuration σ2π2δ2 is accompanied by an increase in Mo-Mo distance, 2.237 (1)-2.508 (2) A?. Related ditungsten alkoxide β-diketonates (M≡M) fail to react with t-BuNC under comparable conditions. Both molybdenum and tungsten alkoxide β-diketonates fail to react with CO and alkynes under conditions wherein M2(OR)6 and M2(OR)6(L)2 compounds yield M2(μ-X) derivatives (X = CO, alkynes) or products of cleavage of the M-M bond. Mo2(OCH2-t-Bu)4(MeCOCHCOMe)2 reacts with 2,2′-bipyridine to give Mo2(OCH2-t-Bu)4(MeCOCHCOMe)2(bpy), which, on the basis of 1H NMR spectroscopy, is proposed to be an edge-shared (μ-OR) bioctahedral compound. The marked differences in reactivity of M2(OR)6 and the mixed alkoxide β-diketonate complexes are discussed in terms of kinetic and/or thermodynamic factors.
Redox chemistry of hexakis(phenyl isocyanide) complexes of molybdenum and tungsten: The synthesis of the seven-coordinate cations [M(CNPh)7]2+ and their electrochemistry and substitution reactions
Klondworth, Douglas D.,Welters Iii, Warren W.,Walton, Richard A.
, p. 336 - 343 (2008/10/08)
The reactions of the quadruply bonded tungsten complexes W2(mhp)4 and W2(dmhp)4 (mhp and dmhp re the anions of 2-hydroxy-6-methylpyridine and 2,4-dimethyl-6-hydroxypyrimidine, respectively) with excess phenyl is
