14220-65-6Relevant academic research and scientific papers
Selective epoxidation of olefins over Co(II)-Schiff base immobilised on KIT-6
Visuvamithiran,Palanichamy,Shanthi,Murugesan
, p. 31 - 38 (2013)
Co-Salen complex immobilised on amine functionalised mesoporous KIT-6 (Co-S-KIT-6) was prepared by post synthetic method. The synthesised materials were characterized by techniques such as small angle XRD, FT-IR, DRSUV-vis, thermal analysis, N2 sorption, ESR, SEM and TEM. The small angle XRD patterns, N2 sorption studies and TEM images clearly revealed immoblisation of Co-Salen complex inside the pores of KIT-6. Further, decrease in the surface area, pore volume and pore diameter compared to parent KIT-6 also confirmed the immobilisation of Co-Salen complex inside the mesopores. The catalytic activity of Co-S-KIT-6 was tested in the liquid phase epoxidation of olefins using H2O2 as the oxidant. The influence of reaction parameters such as catalyst amount, reaction temperature, solvent and reaction time on the catalytic activity of Co-S-KIT-6 was also studied. The solvent polarity played a key role in the conversion and selectivity. Polar aprotic solvent such as acetonitrile exhibited high conversion with high selectivity of the product. Further, it was demonstrated that Co-S-KIT-6 can be recycled upto five cycles without loss of its catalytic activity. In addition, the catalyst was found to be highly active, stable and selective.
Morphologies and magnetic properties of FeCo nanoparticles modulated by changing the types of ligands of Co
Alikhanzadeh-Arani, Sima,Salavati-Niasari, Masoud,Almasi-Kashi, Mohammad
, p. 3652 - 3657 (2012/09/22)
A new way of preparing FeCo nanoparticles has been developed using the co-precipitation technique based on the appropriate Co precursors of different types of ligands. These new precursors have been prepared by the reaction of cobalt acetate with three various coordination compositions for forming cobalt complex types. This technique provides proper control on nanoparticle size distribution after annealing to 500 °C. The variation of the magnetic properties with the type of ligands of Co can arise from the changes of the microstructures and crystalline anisotropies. Maximum coercivity values of 480 Oe were obtained. It is found that the precursors with special structures can prevent from agglomeration without presence of any surfactants.
Synthesis, characterization and catalytic activity of Mn(III)- and Co(II)-salen complexes immobilized mesoporous alumina
Chaube,Shylesh,Singh
, p. 79 - 87 (2008/10/09)
Mn(III) and Co(II)-schiff base complexes were immobilized over mesoporous alumina through the reaction of mesoporous alumina functionalized 3-aminopropyl triethoxy silane (3-APTES) and salicylic aldehyde via schiff base condensation. The surface propertie
Regioselective Formation of Peroxyquinolatocobalt(III) Complexes in the Oxygenation of 2,6-DI-t-butylphenols Schiff-base Complexes
Nishinaga, Akira,Tomita, Haruo,Nishizawa, Kanji,Matsuura, Teruo,Ooi, Shunichiro,Hirotsu, Ken
, p. 1504 - 1514 (2007/10/02)
The oxygenation of 2,6-di-t-butylphenols with five-co-ordinated cobalt(II) Schiff-base complexes in aprotic solvents, such as CH2Cl2, thf, and dmf (thf = tetrahydrofuran, dmf = dimethylformamide), has been found to result in regioselective formation of peroxyquinolatocobalt(III) complexes.The regioselectivity depends on the nature of the substituent at the 4-position of the phenol used: 4-alkyl-2,6-di-t-butylphenols(1) afford peroxy-p-quinolatocobalt(III) complexes, whereas peroxy-o-quinolato-complexes are formed from 4-aryl-2,6-di-t-butyl-phenols (4).The initiation of the oxygenation is hydrogen abstraction by superoxocobalt(III) species from the phenols to give the corresponding phenoxy-radicals (10).Rapid reduction of (10) with cobalt(II) species follows giving rise to a phenolatocobalt(III) complex intermediate, within which dioxygen is incorporated.The regioselectivity of the oxygenation is attributable to the formation of the phenolatocobalt(III) complex intermediate.Crystals of the peroxy-p-quinolatocobalt(III) complex (2a) are orthorombic, space group P212121, with a = 33.749(11), b = 11.844(5), c = 9.329(4) Angstroem, and Z = 4.The crystal structure has been refined from 3 018 diffractometer data to R = 0.067.
