(Urea)_n(n=2～5)内分子间相互作用的理论化学研究  

Theoretical study of the intermolecular interactions in (Urea)_n(n=2～5)

作　　者：宫利东[1] 郑胜男 卜聪明 刘翠[1] 杨忠志[1] GONG Lidong;ZHENG Shengnan;BU Congming;LIU Cui;YANG Zhongzhi(School of Chemistry and Chemical Engineering,Liaoning Normal University,Dalian 116029,China)

机构地区：[1]辽宁师范大学化学化工学院

出　　处：《辽宁师范大学学报（自然科学版）》2019年第4期477-485,共9页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目（20703022;21603091）;辽宁省科技厅自然基金计划指导项目（20180550163）

摘　　要：用MP2/6-311++^G**//B3LYP/6-311++G^**方法对(Urea)n(n=2~5)复合物进行结构优化、频率和结合能的计算,并考虑基组重叠误差.研究发现,(Urea)n(n=2~5)中存在N-H…O和N-H…N两种类型的氢键,其中,N-H…O型氢键键长较短,氢键角较大,作用强度较大.通过Mulliken电荷布居分析,发现复合物中参与形成氢键的原子所带电荷变化明显,而没有参与形成氢键的原子电荷几乎不变.基于原子-键电负性均衡方法,确定尿素团簇的相关ABEEM电荷参数,计算得到的电荷分布与量子化学结果有很好的一致性.In terms of quantum chemical calculations,the optimized structures,vibrational frequencies and binding energies of (Urea) n ( n =2~5) were obtained at the MP2/6-311++G^ ** //B3LYP/6-311++G ^** level with the basis set superposition error correction. Results show that there are 2 types of hydrogen bonds in the urea clusters,N—H…O and N—H…N. The hydrogen bond length of N—H…O is shorter than that of N—H…N. Moreover,the hydrogen bond angle of the former type is bigger than that of the later one. According to the Mulliken population analyses,evident charge transfer is observed between the hydrogen bonding atoms,while almost no charge transfer among the other atoms. Based on the ABEEM,we adjusted and determined the ABEEM charge parameters. The ABEEM charge distributions of the (Urea) n ( n =2~5) are in good consistency with those of QM results.

关 键 词：尿素团簇 氢键 结合能 电荷转移 ABEEM 

分 类 号：O641.121[理学—物理化学]