138259-25-3Relevant academic research and scientific papers
Spectroscopic comparisons of MoW(porphyrin)2 heterodimers with homologous Mo2 and W2 quadruple bonds: A dynamic NMR and resonance raman study
Collman, James P.,Harford,Franzen, Stefan,Eberspacher,Shoemaker, Richard K.,Woodruff, William H.
, p. 1456 - 1465 (2007/10/03)
The rotational barrier for MoW(meso-monotolyl octaethylporphyrin)2 ([(TOEP)MoW(TOEP)]) has been determined (ΔG((+))(rot) = 10.6 ± 0.1 kcal/mol) by variable-temperature NMR and complete band shape analysis and is compared with values previously obtained for the analogous homodimers. The overall quadruple bond strengths of these isostructural dimolybdenum, ditungsten, and molybdenum - tungsten porphyrin dimers have also been compared by calculation of the force constants corresponding to each metal - metal bond stretching frequency as observed by resonance Raman spectroscopy. The Raman results are as follows: [Mo(OEP)]2, ν(MoMo) = 310 cm-1, k = 2.72 mdyn/A?; [(OEP)MoW(OEP)], ν(MoW) = 279 cm-1, k = 2.89 mdyn/A?; [Mo(TOEP)]2, ν(MoMo) = 310 cm-1, k = 2.72 ν(MoMo) [W(TOEP)]2 ν(WW) = 275 cm-1, k = 4.08 mdyn/A?; and [(TOEP)-MoW(TOEP)], ν(MoW) = 278 cm-1, k = 2.89 mdyn/A?: [MoMoW(TOEP)]. Both the 1H NMR and Raman specta are consistent with a [(Por)MoW(Por)] structure wherein the Mo(Por) congener experiences a more drastic 'bending-back' distortion of the porphyrin macrocycle.
Relative strength of 4d vs 5d δ-bonds: Rotational barriers of isostructural molybdenum and tungsten porphyrin dimers
Collman, James P.,Garner, J. Michael,Hembre, Robert T.,Ha, Yunkyoung
, p. 1292 - 1301 (2007/10/02)
Rotational barriers about the metal-metal quadruple bond axis in isostructural molybdenum (ΔGrot? = 10.8 ± 0.1 kcal/mol) and tungsten porphyrin dimers (ΔGrot? = 12.9 ± 0.1 kcal/mol) have been analyzed by variabl
