名称:
Synthesis and Characterization of TpiPrMoO(S2PR2) (R = Pri, Ph, OEt, OPri, (−)-Mentholate) and {HB(OMe)(Pripz)2}MoO(S2PPri2), Including Isomers of Known 1,2-Borotropically-Shifted Complexes
摘要:
Green/blue Tp(iPr)MoO(S2PR2) (Tp(iPr) = hydrotris(3-isopropylpyrazolyl)borate; R = Pr-i Ph, OEt, OPri (-)-mentholate) complexes were synthesized and characterized by elemental analysis, mass spectrometry, IR and NMR spectroscopy, and X-ray crystallography. The diamagnetic, six-coordinate, oxo-Mo(IV) complexes possess distorted octahedral geometries defined by terminal oxo, bidentate dithio acid, and tridentate Tp(iPr) ligands. The R = Pri and Ph derivatives are isomers of previously reported 1,2-borotropically shifted complexes, Tp(iPr)* MoO(S2PR2) (Tp(iPr)* = hydrobis(3-isopropylpyrazolyl)(5-isopropylpyrazolyl)borate; ref: Inorg. Chem. 1996, 35, 5368). Conversion of Tp(iPr)MoO (S2PPh2) into Tp(iPr)*MoO(S2PPh2) at elevated temperatures (>80 degrees C) showed that the borotropically shifted isomer was thermodynamically more stable than the unshifted species. Reaction with methanol converts Tp(iPr)MoO(S2PPr2i) into {HB(OMe)(Pr(i)pz)(2))MoO(S2PPr2i) (Pr(i)pz = 3-isopropylpyrazolyl), which was characterized by spectroscopic and crystallographic methods.