The reaction of Nb＋ with CS2, producing cationic transition-metal sulfide and CS, was taken as a representative example to elucidate the overall mechanism of reactions of second- row early transition metal ions with CS2. The reactions in both triplet and quintet state were studied by using the UB3LYP density functional method with the Stuttgart pseudo potentials and corresponding basis sets for Nb＋ and the standard 6-311＋G（2d） basis sets for C and S. The geometries for reactants, the transition states, and the products were completely optimized. All the transition states were verified by vibrational analysis and intrinsic reaction coordinate calculations. The results show that the reaction mechanism between niobium ion and CS2 is an insertion-elimination mechanism. Intersystem crossing may occur in the reaction Nb＋ with CS2 and a minimum energy crossing point was found.
研究了海红果渣总黄酮(T FMM)的体外抗氧化作用,测定了T FMM对油脂过氧化、脱氧核糖氧化损伤的抑制作用以及对超氧阴离子(O-2)的清除作用,并与BHT比较。结果显示,T F M M对脂质过氧化以及脱氧核糖氧化损伤有明显的抑制作用,对超氧阴离子(O-2)有较强的清除作用,效果明显优于同浓度的BHT。且随着海红果总黄酮添加量的增加,对脂质过氧化、脱氧核糖氧化损伤的抑制作用以及超氧阴离子(O-2)的清除抑制作用也随之增强。
