14126-40-0Relevant articles and documents
Epoxidation of cyclohexene with O2 and isobutyraldehyde catalysed by cobalt modified hydrotalcites
Angelescu,Ionescu,Pavel,Zǎvoianu,B?rjega,Luculescu,Florea,Olar
, p. 178 - 186 (2010)
The paper presents a comparison between the catalytic performances of cobalt modified hydrotalcites obtained from different cobalt precursors in the epoxidation of cyclohexene using molecular oxygen, isobutyraldehyde as reductant, at 25 °C and 1 atmosphere pressure of oxygen in acetonitrile as solvent. Two different types of cobalt containing catalysts were prepared - (i) a hydrotalcite-like compound containing cobalt in the brucite type layer, CoMg/Al, and (ii) three catalysts obtained by impregnation of the as-synthesized hydrotalcite support (HT) with CoCl2, bis-triphenylphosphine-dichlorocobalt (II) Co P(C6H5)32Cl2, (A), and an admixture of complexes (AB) containing bis-triphenylphosphine-dichlorocobalt (II) Co P(C6H5)32Cl2 (A) and benzyltriphenyl phosphonium-tetrachlorocobaltate C6H5CH2P(C6H5) 32+ CoCl42- (B). The names of these catalysts have been abbreviated as CoCl2/HT, A/HT and AB/HT. The catalysts were characterized by chemical analyses, DR-UV-vis, DRIFTS, XRD, EDX and texture measurements. The most active and selective catalyst was AB/HT. A linear correlation between the ratio Cl/Co in the resulting solids and the yield to epoxide has been established. For AB precursor the effect of the support has been also investigated using as carriers the mixed oxide CHT derived from the calcination of the parent hydrotalcite, and the reconstructed hydrotalcite RHT obtained by rehydration of CHT.
Mixed ligand cobalt and palladium complexes containing triphenylphosphine and a hydrazone: Synthesis and application in non-linear optics
Ramakrishna, Dileep
, p. 462 - 466 (2020/07/30)
Mixed ligand complexes of cobalt and palladium containing triphenylphosphine and a hydrazone derived from furfural and hydrazine hydrate have been designed, synthesized, evaluated, and characterized from their spectral properties, elemental analysis, and magnetic susceptibility measurements. The spectral techniques suggest that the complexes exhibit square planar geometry. The monomeric properties of the complexes are evaluated from their magnetic susceptibility values. The complexes were subjected to z-scan analysis for third-order non-linear optical measurements. Non-linear transmission measurements performed using laser pulses at 532 nm in nanosecond indicate that the complexes may show good potential as optical limiters.
Alkene isomerization-hydroboration promoted by phosphine-ligated cobalt catalysts
Scheuermann, Margaret L.,Johnson, Elizabeth J.,Chirik, Paul J.
supporting information, p. 2716 - 2719 (2015/06/16)
Generated in situ from air-stable cobalt precursors or readily synthesized using NaHBEt3, (PPh3)3CoH(N2) was found to be an effective catalyst for the hydroboration of alkenes. Unlike previous base-metal catalysts for alkene isomerization-hydroboration which favor the incorporation of boron at terminal positions, (PPh3)3CoH(N2) promotes boron incorporation adjacent to π-systems even in substrates where the alkene is at a remote position, enabling a unique route to 1,1-diboron compounds from α -dienes.
