Molybdenum complexes. 1. Acceptor behavior and related properties of Mo(VI)O2(tridentate) systems

Synthesis, characterization and catalytic epoxidation of cyclohexene using dimeric cis-dioxomolybdenum(VI) bis-bidentate Schiff base complexes supported on single wall carbon nanotubes

“…All three of these Schiff bases contain two salicyladimine chelating sites separated by different flexible bridging groups; -C 6 [24]. The ring skeletal vibrations (C=C) were consistent in all derivatives and unaffected by complexation.…”

Hydroxylation of Phenol Catalyzed by Oxovanadium(IV) of Salen-Type Schiff Base Complexes with Hydrogen Peroxide

“…A strong bands at 1,614-1,625 cm -1 in the ligands spectra are assigned to the azomethine (C=N) stretching vibration. This band shifted to lower frequency in the complexes due the coordination of nitrogen atom of the azomethine group to the central metal [29][30][31][32]. Unlike m(C=N) stretching bands, the m(C=C) stretching mode does not show any significant shift.…”

Epoxidation of alkenes in the presence of molybdenum–squarate complexes as novel catalysts

“…GLC analysis was combined with both the titrimetric determination of alkene oxide in non-aqueous medium [24] and standard hydroperoxide iodometric method. The molybdenum content in the complexes synthesized was evaluated by thermal gravimetric analysis (TGA) using OD-102 instrument (MOM, Hungary) by igniting the sample to MoO 3 up to 650-700 8C with the complete loss of organic matter [25]. The IR spectrum of the inorganic residue was identical to that of commercial MoO 3 .…”

“…For example, complexes, in which the squarate is coordinated through all four oxygen atoms exhibit a strong band near 1500 cm À1 , assigned to a mixture of C-C and C-O stretching vibrations [30]. For all molybdenum-containing squarate complexes, the characteristic doublets (sometimes with shoulders) observed in the 900-950 cm À1 region and attributed to the cis-MoO 2 fragment [21,23,[31][32][33] were of a high analytical value. The positions and the intensities of the corresponding bands depended strongly on the kind of the organic nitrogencontaining fragment involved in the complex formation.…”

“…[34,35]. The formation of strongly polar Mo-O bond with an organic ligand [33] (most probably, the squarate moiety) resulted in one of the strongest band observed in the spectrum of the complex at 551 cm À1 .…”