苯与羰基钼相互作用的密度泛函研究

Density functional theory study of interactions between C_6H_6 and Mo(CO)_n(n=1-5) complexes

用密度泛函理论在B3LYP/LANL2DZ基组水平上自由优化（η~x-C_6H_6）Mo（CO）_n（x=1-6;n=1-5）复合物体系的可能构型及计算相互作用能,探索不同羰基数对复合物稳定性、苯和羰基钼相互作用的影响,并分析苯和羰基钼相互作用的NBO。结论（1）苯以η~6与Mo（CO）_n（n=1-3）配位形成的复合物比较稳定,但η~6配位复合物CO的个数越多,则越不稳定;（2）复合物1、2、3和10中,Mo（CO）_n与苯的相互作用拉动电荷由苯的π键电子向Mo（CO）_n的σ_（Mo-CO）~＊键转移,而在复合物7中,苯的π键电子向Mo（CO）_n中Mo的孤对电子轨道d转移。

In order to study the effects of a number of CO groups on the Mo（CO）_n-C_6H_6 interactions,the structures of（η~x-C_6H_6）Mo （CO）_n（x=1-6;n=1-5） complexes were studied by using the density functional theory B3LYP method with LANL2DZ basis set and 10 geometries were obtained.Nature bond orbital（NBO） analyses were also performed to explain the nature of the Mo（CO）_n-C_6H_6 interactions.The conclusions can be drawn as follows：（1） the most stable geometries of Mo（CO）_n-C_6H_6 complexes are the configuration of（η~6-C_6H_6） Mo（CO）_n when＂n＂value is from 1 to 3.The more CO groups there are,the lower is the stabilitity of the complex. （2） Through the Mo（CO）_n-C_6H_6 interactions,there is the great charge transfer fromπbond of benzene towardsσ_（Mo-CO）~＊ of Mo（CO）_n in the 1,2,3 and 10 complexes,however there is charge transfer betweenπbond of benzene and lone pair electron d orbital of Mo atom.