The Oxidation Behavior of Potato Starch and Benzyl Alcohol via Peroxide in the Catalysis of Metal Complexes

Abstract

Two new Schiff bases ligands (HL1 and HL2) and their Co2+, Mn2+, Fe3+, Ru3+, Cr3+, and VO2+ complexes were synthesized and characterized by FT‐IR, 1H‐NMR, and Mass spect. and analytical methods. A single‐crystal X‐ray diffraction study determined the molecular structure of HL1. The catalytic effects of metal complexes on benzyl alcohol and potato starch (PS) oxidation were compared in an H2+O2 medium. The percent conversion of benzyl alcohol to benzaldehyde and benzoic acid was determined by Gas Chromatography. [Co(L1)2], [Mn(L1)2], [Co(L2)2], and [Mn(L2)2] showed the highest catalytic effect with a value between 97–98% in the conversion of benzyl alcohol to benzaldehyde and benzoic acid. Maximum % benzoic acid formation was observed in [Mn(L1)2] (39%) and [VO(L1)2] (58%). To determine the effect of the catalyst properties of the complexes on the oxidation of PS, carbonyl and carboxyl groups formed in potato starch were determined by the titrimetric method, and PS oxidation degrees were calculated as DS (DSCHO and DSCOOH). In potato starch oxidation, the [VO(L1)2] had the highest catalytic effect with DSSum = 0.96, while the [Mn(L1)2] had a relatively lower DSSum = 0.86 value. On the other hand, the [Cr(L2)2ClH2O] showed a catalytic impact with DSSum = 0.63.