中性和阳离子丁酮团簇的结构及稳定性的理论研究  

Theoretical study on the structure and stability of neutral and cationic butanone clusters

作　　者：杨雪[1,2] 丁大军[2] 胡湛[2] 赵国明[1] Yang Xue;Ding Da-Jun;Hu Zhan;Zhao Guo-Ming(College of Science, Jilin Institute of Chemical Technology, Jilin 132022, China;Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China)

机构地区：[1]吉林化工学院理学院,吉林132022 [2]吉林大学原子与分子物理研究所,长春130012

出　　处：《物理学报》2018年第3期85-93,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11447194);吉林省教育厅"十三五"科学技术项目(批准号:JJKH20170215KJ)资助的课题~~

摘　　要：使用密度泛函B3LYP方法,在6-31G*和6-311+G**基组水平上计算中性和阳离子丁酮团簇(CH_3COC_2H_5)_n和(CH_3COC_2H_5)_n^+(n 7)的稳定结构,并比较不同尺寸团簇之间的相对稳定性.中性和阳离子丁酮团簇的结构具有相似性:n=3—7时,组成团簇的丁酮的平均几何参数基本相同,单环结构最稳定;随着团簇尺寸的增加,双环结构的稳定性逐渐上升.通过平均结合能、一阶差分能、HOMO-LUMO能隙等计算分析可知:在所研究的各种尺寸团簇中,(CH_3COC_2H_5)_3是最稳定的中性团簇,与实验中的最强峰对应;(CH_3COC_2H_5)_4^+是最稳定的阳离子团簇.通过电离能计算得到丁酮分子的垂直电离能为9.535 eV与实验值相符,同时证明中性和阳离子丁酮二元团簇的结构变化较大.研究结果为实验中丁酮团簇碎片离子的形成机理提供一定的理论依据,并且为进一步研究酮类分子团簇的生长规律提供有价值的信息.The molecular clusters have attracted increasing attention in recent years due to their applications in areas of laser, synchrotron radiation, molecular beam and time-of-flight mass spectrometry. The cluster structures can be speculated by the mass spectrum measurement and predicted by the quantum chemical methods. It is very important for understanding the solvation kinetics and nucleation to explore the formation and growth of clusters. Meanwhile, it is also beneficial to understanding the atomic or intermolecular interactions in the clusters. The molecular clusters have been studied in our previous work. The acetone clusters （CH3COCH3）n （n ≤ 12） were observed by 355 nm pumping laser. The structures of （CH3COCH3）n with n=2-7 were calculated by density functional theory, and some structures of clusters with low energy were given. Subsequently, several butanone cluster fragment ions and protonated butanone （CH3COC2H5, which is formed by taking a methyl change into ethyl from acetone CH3COCH3） clusters were observed by measuring the mass spectra under the irradiations of 355 nm and 118 nm laser lights, respectively. It is important to determine the stable cluster structures and explain the dynamics of the clusters by theoretical calculation. The stable geometric structures of neutral and cationic butanone clusters are optimized at B3LYP/6-31G＊ and B3LYP/6-311＋G＊＊ levels based on the density functional theory. The structural characteristics and stabilities of butanone clusters with various sizes are also analyzed. The average binding energy, first-order difference energy, HOMO-LUMO gap and ionized energy are further discussed systematically in the present work. The results show that the structures of （CH3COC2H5）n and （CH3COC2H5）n＋ have similar characteristics, single-ring structure is the most stable for them when n=3-7, and the structures also occur in some hydrogen bonded clusters, such as （H2O）n （n=3-6）, （NH3）n （n=3-6）, （CH3OH）n （n=3-6）, and （HCHO�

关 键 词：丁酮团簇 结构 稳定性 密度泛函理论 

分 类 号：O641.1[理学—物理化学]