Rare Examples of Biomimicking Molybdenum(VI) Catalysed Peroxidative Bromination of the Organic Substrates that Coordinate to the Oxido-Diperoxido Mo(VI) Centre

摘要

The two novel oxido-diperoxido molybdate(VI) complexes [MoO(O2)2{BHPPM]. PPh4 (1) [BHPPM=5-bromo-2-hydroxyphenyl( phenyl)methanone] and [MoO(O2)2 {DBHPPM}]. PPh4 (2) [DBHPPM=3,5-dibromo-2-hydroxyphenyl(phenyl)methanone] with 2-hydroxyphenyl(phenyl)methanone and 2-hydroxyphenyl (phenyl)methanoneoximato ligands have been synthesized by adding methanolic solution of the ligand to the pale yellow solution obtained by dissolving molybdic acid in hydrogen peroxide and precipitating the complexes using tetraphenylphosphonium bromide. The complexes were characterized by IR, UV-vis, Mass, CHN, molar conductance, magnetic moment, mass and ~1HNMR spectro- scopic methods. Molecular structure of oxido-diperoxidomolybdate(VI) (1) and (2) were established by X-ray crystallography. The ligand first coordinates to the molybdenum(VI) in presence of hydrogen peroxide, thereafter, molybdate(VI) catalysed peroxidative bromination of the ligand takes place during the synthesis of the oxido-diperoxidomolybdate( VI) complexes with the above in situ generated brominated ligands.