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应用Meld程序在MP2-OPT2/6-311++G(d)水平计算了线性氟代烷烃分子CH3(CH2)mF(m=0-5)中-CH3、-CH2-和-F基团电子相关能贡献值.计算结果表明,在CH3(CH2)mF(m=0-5)体系中,端基-F、-CH3基团电子相关能贡献值Ecorr(-F)和Ecorr(-CH3)随着m的增大而逐渐减小.分子中α位置-CH2-基团电子相关能贡献值Ecorr(-CH2-)大于其他位置的贡献值.通过计算结果可以推断,在CH3(CH2)mF体系中随着m的逐渐增大,远离端基-F的-CH2-基团电子相关能贡献值逐渐减小并将趋于不变,此-CH2-基团可看作一个标准的亚甲基且其Ecorr(-CH2-)的数值在CH3(CH2)mF体系中具有传递性.应用Meld程序在MP2-OPT2/6-311++G(d)水平对CH3(CH2)mF(m=2-5)体系的计算结果和应用Gaussian98程序在MP2/6-311++G(d)//HF/6-311++G(d)水平对CH3(CH2)mF(m=2-10)体系的计算结果均表明,体系总电子相关能与体系中(m-1)数值呈线性关系.
In the MP2-OPT2 / 6-311 ++ G (d) level, the electron of the -CH3, -CH2- and -F groups in the linear fluoroalkane molecule CH3 (CH2) mF (m = 0-5) The results show that the contribution of electron-dependent energy Ecorr (-F) and Ecorr (-CH3) of terminal -F and -CH3 groups in CH3 (CH2) mF (m = 0-5) Decreases with the increase of m, and the contribution of electron-dependent energy Ecorr (-CH2-) in the α-position -CH2- group in the molecule is larger than the contribution of other positions. From the calculation results, it can be inferred that in CH3 (CH2) mF With the increasing of m in the system, the electron-dependent contribution of the -CH2- group far away from the end group -F gradually decreases and will tend to be constant. The -CH2- group can be regarded as a standard methylene And the value of Ecorr (-CH2-) is transitive in CH3 (CH2) mF system. The CH3 (CH2) mF (m = 2-5) system calculations and application of the Gaussian98 program to CH3 (CH2) mF (m = 2-10) at MP2 / 6-311 ++ G (d) // HF / 6-311 ++ G ) System shows that there is a linear relationship between the total electronic correlation energy and the (m-1) value of the system.