摘要
膦配位的过渡金属氢化物被看作是烯烃及其他一些不饱含有机化合物催化加氢反应及氢甲酰化反应的催化活性物种,关于它们的结构与催化活性关系的研究,有着重要的理论意义和实际意义,通常单齿膦配位表现出较高的催化活性,而不同的金属中心在催化活性和选择性上也表现出明显的差别,反映了催化功能与催化活性物种的电子结构和空间结构之间存在着依存关系.膦配体过渡金属氢化物。
Organophosphorus transition metal hydride complexes have attracted considerable interest, especially concerning the catalytic hydrogenation and hydroformylation. Here we reported the synthesis, characterization and catalytic hydrogenation activity of HRh(DPPE)2, HCo(DPPE)2 and H2Ru(DPPE)2. These hydrides were synthezed by one-step method using RhCl3 ?3H2O, CoCl2 and RuCl3 ?3H2O together with DPPE and Na/Hg amalgam in tetrahydrofuran respectively. Their IR spectra showed that v_(Rh-H)=1900 cm-1, v_(co-H)=1884 cm-1and v_(Ru-H)=1885 cm-1. Their high field 1H NMR single shows at δ_(Rh-H)= - 10. 19 ppm and δ_(Ru-H)= -8. 34 ppm. These results proved that Rh -H, Co-H and Ru-H bonds exist in these hydrides.
The catalytic hydrogenation activities of these hydrides for hexene- 1 showed apparent differences. The activity order was HRh ( DPPE )2 > H2Ru ( DPPE )2 > HCo ( DPPE )2. The hydrogencation rates were determined under different concentration of hexene-1, and treated with the Michaelis-Menten equation for enzymic reaction. A linear correlation was obtained.
The IR and high field 1H NMR spectra during the reaction of hexene-1 with HRh(DPPE)2 and H2Ru(DPPE)2 were studied respectively, and the catalytic hydrogenation mechanism was discussed.
出处
《分子催化》
EI
CAS
CSCD
1993年第1期62-66,共5页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金资助项目.
关键词
膦
络合物
催化加氢
活性
Bidentate phosphine complexes, Catalytic hydrogenation, Hexene.
