甲醛和氟代甲醛在不同溶剂中溶剂化效应的理论计算  

A Theoretical Computation of Solvent Effect for H_2CO and F_2CO in the Various Solvents

作　　者：刘玲玲[1] 王桂良[1] 张力[1] 常国华[1] 张国富[1] 

机构地区：[1]兰州城市学院化学与环境科学学院,甘肃兰州730070

出　　处：《甘肃科学学报》2009年第2期64-68,共5页Journal of Gansu Sciences

摘　　要：采用密度泛函UB3LYP/6-311+G**方法,结合极化连续模型(PCM)计算不同介电常数的溶剂对甲醛和氟代甲醛的溶剂化效应及对其振动频率的影响.计算结果表明,溶剂极性不影响甲醛和氟代甲醛分子C2v点群对称性.甲醛及氟代甲醛的C=O键强度均随着溶剂介电常数的增大逐渐减弱,氟代甲醛的减弱较甲醛明显.无论是在气相中还是在溶剂中,氟代甲醛的C=O键强度大于甲醛的C=O键强度.氟代甲醛分子中的C=O键在溶剂中随着溶剂介电常数的增大,键的极性逐渐增强.甲醛和氟代甲醛分子处在极性溶剂还是非极性溶剂中,其能量总是低于气相状态能量.The solvent effects of HzCO and FzCO in some solvents which have differential dielectric con- stants were calculated out using UB3LYP method and PCM model at the 6-311＋G^＊＊ level. The results indicated that the polarity of solvents did not influence the C2v symmetry group of H2CO and F2CO. The bond strength of C= O in HzCO and F2CO increased with the dielectric constant raising, and the C= O bond of FzCO was stronger than that of H2CO in the solvents and the gas phase. HzCO and F2CO in the solvents,no matter how strong the solvent polarity is,were more stable than those in the gas phase.

关 键 词：甲醛及氟代甲醛 密度泛函 溶剂化效应 频率分析 

分 类 号：O621.13[理学—有机化学]