稀土元素R4OCl6四面体嵌合物的化学键研究

以SCC-DV-X,方法对Sm_4OCl_6、Eu_4OCl_6、Yb_4OCl_6和Gd_6N_2Cl_(12)等4个体系作了量化计算。结果表明,嵌入原子在四面体簇的合成中起决定性作用。体系6个骨架轨道中,3个是嵌入原子与稀土原子的成键轨道,另3个是稀土原子通过嵌入原子形成的弱键轨道。用Sm、Eu等元素能合成四面体嵌合物,与其价态较低有关,低价态使稀土元素d、f轨道收缩较少、成键能力增大。而富含f电子的Yb体系,4f为主要价轨道。

Investigation on Chemical Bond for Interstitial Compounds of Rare-Earth Element Tetrahedral Cluster R4OC16

Four systems Sm4OCl6, Eu4OCl6, Yb4OClc and Gd6N2Cl12 were calculated by using SCC-DV-X. method. It is found that the interstitial atom plays a determinative role in syntheses of tetrahedral cluster. There are six skeleton orbitals in the compound, three of them are formed from the interstitial atom oxygen and the rare-earth atoms, and the others are bonded by the 4f orbitals of the rare-earth atoms, pass through the embeded atom. In addition, the tetrahedral interstitial compounds may be synthesized successfully, because elements Sm, Eu etc. are in the lower valent states which make the contraction of d and f orbitals lessen and the bonding capability increase. And rich-electron f orbitals in Yb-system have become the major valence orbitals.