The use of tetraalkylammonium salts or imidazolium ionic liquids in catalytic oxidations of alcohols with tetra-N-propylammonium perruthenate allows recovery and reuse of the oxidant; this concept may find application in the recovery of other homogenous catalysts.
The influence of a non-micelle-forming surfactant on the electrocatalytic hydrogenation of carvone and limonene in aqueous medium at Raney nickel electrodes
作者:Valérie Beraud、Marc Thomalla、Jean Lessard
DOI:10.1139/v97-184
日期:1997.11.1
and limonene (8) at a Raneynickel cathode was studied in aqueous solutions containing a non-micelle-forming surfactant (didodecyldimethylammonium bromide, DDAB). The efficiency of ECH of these substrates was markedly increased compared to that observed previously with micelle-forming surfactants, and this for very low DDAB concentrations, as a consequence of the strong adsorption of DDAB on the electrode
Circular Dichroism of Nitrate Esters: A Planar Symmetry Rule for the Nitrato Chromophore
作者:R. E. Barton、L. D. Hayward
DOI:10.1139/v72-273
日期:1972.6.1
in the isotropic electronic spectra were resolved in the circulardichroism spectra. Band I (270 nm) reflected nitrato group libration changing sign and magnitude with changes in temperature and solvent polarity. Differences in rotatory strength of band III (210 nm) for cis- and trans-dinitrates indicated transition moment coupling. A planar symmetry rule for chromophores in the Cs point group correlated
基于 X 射线和光谱数据的硝酸酯构象分析表明,硝基与 α 碳原子共面,在优选的旋转异构体中,硝基部分与 β 碳原子反周。在各向同性电子光谱中不明显的三个光学活性吸收带在圆二色光谱中被解析。波段 I (270 nm) 反映了硝基基团的振动随着温度和溶剂极性的变化而改变符号和幅度。顺式和反式二硝酸盐的带 III (210 nm) 旋转强度的差异表明过渡矩耦合。Cs 点群中发色团的平面对称规则与 42 种硝酸酯的分子几何形状和带 II 的符号相关:
Hydrogénolyse en phase liquide sur Pd/C des époxydes du carvomenthène et du limonène
double bond migration, hydrogenation of which leads to the products. For the carvomenthene epoxides the results are similar to those found in the 4-t-butyl series with competition between cisaddition and trans addition of hydrogen. The presence of the isopropenyl group leads to slower reactionrates in comparison with t-butyl analogues.