巯基化合物键离解能的密度泛函和CBS-Q方法研究  

Theoretical Studies on Bond Dissociation Energies for Some Thiol Compounds by Density Functional Theory and CBS-Q Method

作　　者：张瑞州[1] 牛芳[2] 

机构地区：[1]河南科技大学理学院,河南洛阳471003 [2]河南大学文理实验班学院,河南开封475001

出　　处：《新乡学院学报》2009年第3期45-48,共4页Journal of Xinxiang University

基　　金：国家自然科学基金(10774039)

摘　　要：利用密度泛函方法(B3LYP、B3PW91、B3P86、PBE0)结合6-311G**基组和完全基组(CBS-Q)方法计算了15种巯基化合物的键离解能。结果表明,CBS-Q和B3P86是计算巯基化合物键离解能的可靠方法。为了检验非局域BLYP方法是否适合研究巯基化合物的键离解能以及B3P86方法是否对基组敏感,利用BLYP/6-31+G*方法和B3P86方法结合6-31+G*、6-31+G**和6-311+G**基组,计算了7种巯基化合物的键离解能,并将所得结果与实验结果进行了比较,研究发现B3P86方法对基组不敏感。考虑到CBS-Q方法的计算成本和B3P86计算的可靠性,B3P86方法结合适中的或较大的基组可以准确计算巯基化合物中C-SH键的离解能。Density functional methods （B3LYP, B3PW91, B3P86, PBE0） and the complete basis set （CBS-Q） method together with 6-311G＊＊basis set are used to estimate the bond dissociation energies （BDEs） for 15 thiol compounds. It is demonstrated that B3P86 and CBS-Q methods are accurate for computing the reliable BDEs for thiol compounds. In order to test whether the non-local BLYP method is general for our study and whether B3P86 method has a low basis sets sensitivity, the BDEs for 7 thiol compounds are also calculated using BLYP/6-31 ＋ G＊and B3P86 method with 6-31＋G＊, 6-31＋G＊＊and 6-311＋G＊＊ basis sets for comparison. The obtained results are compared with the available experimental results. It is noted that B3P86 method is not sensitive to the basis set. Considering the inevitably computational cost of CBS-Q method and the reliability of the B3P86 calculations, B3P86 method with a moderate or a larger basis set may be more suitable to calculate the BDEs of the C- SH bond for thiol compounds

关 键 词：密度泛函理论 键离解能 巯基化合物 CBS—Q方法 

分 类 号：O152[理学—数学]