Abstract: The electronic structure,bond character,and reaction mechanism of phenyl rare earth complex,C₆H₅GdCl₂·4THF,have been studied by using INDO method.The results obtained show that the Lewis acidity of Gd ion is weakened and polarity of Gd-Cl bond is decreased in the ethyl ether with a weak polarity,and substitution of GdCl3 with phenyl lithium as soft base is forced.After electron-withdrawing phenyl substituted Cl,the positive charge of the rare earth ion is increased.The bond order of bond between phenyl and rare earth ion is larger than that of π bond between neutral benzene and rare earth ion,so the covalency of the former is larger than that of the latter.The redistribution of the valent charges caused by the phenyl coordination leads to the weakening of ortho and para C—H bonds of phenyl,and causes some reaction easily.

Key words: Phenyl rare earth gadolinium complex, INDO method, Bonding characteristics