Novel Schiff base Mn(iii) and Co(ii) complexes supported on Co nanoparticles: efficient and recyclable magnetic nanocatalysts for alcohol oxidation

Abstract

In this study, efficient and highly selective heterogeneous catalysts were developed by immobilization of manganese and cobalt Schiff base complexes on Co magnetite nanoparticles (MNPs).

Schiff base Mn(iii) and Co(ii) complexes coated on Co nanoparticles: an efficient and recyclable magnetic nanocatalyst for H2O2 oxidation of sulfides to sulfoxides

“…A weight loss is detected in the range of 300-450 C and 500-750 C, which are predominantly attributed to the decomposition of organic substances in magnetic Co nanoparticles. 15 Therefore, the results of the TG curves correspond to the results of the infrared spectra, which indicate that the surface of the nanoparticles is covered with the ligand functional groups.…”

“…XRD pattern of Co@SiO 2 [(EtO) 3 Si-L 3 ]/Co(II) (curve b) can be assigned to the diffraction from the three major peaks with 2q at 19 , 30 and 40 reection indexes of (100), (200) and (220) planes, respectively (card 25-0250 in the JCPDS le). 15 Fig . 4 shows the TEM images of Co@SiO 2 [(EtO) 3 Si-L 3 ]/Mn(III) (a) and Co@SiO 2 [(EtO) 3 Si-L 3 ]/Co(II) (b).…”

“…[1][2][3][4][5] Schiff base transition metal complexes as catalysts have been widely used because of their potential use in numerous reactions, 6,7 such as hydrogenation of organic substrates, 8 epoxidation of olens, 9 conversion of epoxides into halohydrines, 10,11 asymmetric ring opening of terminal epoxides 12 and oxidation reactions. [13][14][15] In recent years some publications have been reported suldes-oxidation using phthalazine-based di-iron complexes, 16 b-brominated meso-tetraphenylporphyrinato manganese(III) acetate, 17 copper Schiff base complex, 18 immobilized metalloporphyrins, 19 TsOH by phenyliodine diacetate as an oxidant, 20 dendritic bis(acylamino) pyridines, 21 Schiff base of Mn(III) complex supported on magnetic cobalt nanoparticles, 22 Schiff base complexes of Ni, Co, Cr, Cd and Zn supported on Fe 3 O 4 magnetic nanoparticles, 23 magnetic nanoparticle immobilized N-propylsulfamic acid, 24 Au/CTN-silica catalyst, 25 cobalt(II), copper(II), zinc(II) and palladium(II) Schiff base complexes, 26 1,4-bis(3-methylimidazolium-1-yl) butane ditribromide, 27 carboxylated multi-walled carbon nano tubes, 28 1,4-bis(3-methylimidazolium-1-yl) butane ditribromide [bMImB](Br 3 ) 2 ionic liquid reagent 29 and Mo(VI) complex supported on Fe 3 O 4 nanoparticles. 30 In this study, new heterogeneous nanocatalysts were synthesized by chemical modication of surface magnetic nanoparticles of Co with Schiff-base ligands, followed by complex formation through the reaction with Co(II) and Mn(III) salts.…”

Metal–salen molecular cages as efficient and recyclable heterogeneous catalysts for cycloaddition of CO2 with epoxides under ambient conditions

“…S4b in the ESI†). The shifts to a lower frequency in FT-IR indicates that Co and Al have been coordinated onto the salen@cage 23. However, a small shoulder at around 1630 cm –1 can still be seen for Co( ii )@cage and Co( iii )@cage, which may suggest incomplete metalation for these two cage complexes which was confirmed by elemental analysis (Table S1 in the ESI†).…”

Magnetic crosslinked copoly(ionic liquid) nanohydrogel supported palladium nanoparticles as efficient catalysts for the selective aerobic oxidation of alcohols

“…different organic transformations [73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89]. However, to date, few magnetite nanoparticles supported palladium catalysts have been prepared and successfully used in the aerobic oxidation of alcohols.…”