关键词: 八羰基合二钴, 三羰基一氢合钴, 四羰基一氢合钴, 电子结构, 红外光谱, 催化活性

Abstract: Studies on the band positions in IR spectra of Co₂(CO)₈ with the C_2v symmetry and the catalytic activities of the species, HCo(CO)3 and HCo(CO)4,in the reaction of the olefin hydroformylation have been carried out by using quantum chemical calculation at the B3LYP/6-3 1G* level. Two structures of the Co₂(CO)₈, the geometry of C_2v symmetry, as well as the conformation of D_3d symmetry, have been optimized and the structure optimized of C_2v symmetry Co₂(CO)₈ agrees well with experimental structure and is 28.80kJ/mol more stable than D_3d one. The band pos itions in IR spectra of C_2v symmetry Co₂(CO)₈ is well in accord with the experimental studies. It is found that the active catalytic species, HCo(CO)₃ and HCo(CO)₄, have C_2v and C_3vsymmetries, respectively, and that the catalytic activity of HCo(CO)₃ is better than HCo(CO)₄. In addition, the π bond between ethene and HCo(CO)₃ has been formed in the coordinate catalytic reaction and the theoretical bond energy is 100.80kJ/mol.

Key words: Octacarbonyldicobalt, HCo(CO)₃, HCo(CO)₄, electronic structure, IR spectra, catalytic activity