铁钴双核羰基簇合物结构的密度泛函理论研究

DFT study on the structures of FeCo binuclear carbonyl cluster

采用密度泛函理论BPW91方法在6-311+G(d,p)基组水平上,对Fe_(2)、Co_(2)和FeCo团簇吸附CO过程中可能的几何结构和电子态进行了系统研究.结果表明:三种双原子团簇饱和吸附CO分子数分别为9、8、8,吸附的规律各不相同,簇合物的基态均随着吸附CO分子数的增加而减小.吸附过程中金属原子满足18电子规则对CO吸附位置的起主要决定作用,相同的CO数目而言,FeCo的吸附能总体介于Fe_(2)和Co_(2)之间.

Thegeometries and electronic states of Fe_(2) , Co_(2) and FeCo binuclear carbonyl clusters have been investigated by using the BPW91 of density functional theory, with the 6-311+G (d,p ) basis set employed for all atoms. The calculation results indicate that the saturated adsorption amount of the three clusters are 9, 8, and 8, respectively. The clusters have the different rules for the adsorption process, nevertheless, have the same rule for the decrease of spin multiplicity along the reaction path. According to the adsorption of CO on the cluster, we find out that CO prefers to form a specific structure, which follows the 18-electron rule on this side. Furthermore, by analyzing the adsorption energy around three clusters, it can be seen that the FeCo has the middle amount between the Fe_(2) and Co_(2) .