| ASSIGNMENT OF ~(13)C NMR SPECTRA OF POLYMER WITH SEMIEMPIRICAL METHOD——SURVEY OF SPECTRUM OF SECONDARY CARBON OF 1, 2-PBD |
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| 作者姓名： | 高原平 周子南 冯之榴 |
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| 作者单位： | Changchun Institute of Applied Chemistry，Academia Sinica，Changchun 130022，PRC，Changchun Institute of Applied Chemistry，Academia Sinica，Changchun 130022，PRC，Changchun Institute of Applied Chemistry，Academia Sinica，Changchun 130022，PRC |
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| 摘 要： | In chain molecules of 1, 2-PBD, there are two kinds of gauche arrangements, which is the cause of making the spectrum of the secondary carbon in main chain of the polymer split. In such a complex system, the gauche arrangements of the secondary carbon and the tertiary carbon occupy an important position. Hence, the contribution of the tertiary carbon to the chemical shifts of the secondary carbon has a decisive effect on the sequence structure distribution. In comparison the contribution of vinyl groups is much less. The γ values are: γ_1=-6.37～-6.41 ppm represents the effect of the tertiary carbon and γ_2=0.0～-1.56 ppm the contribution of vinyl. The mean square errors are 0.364 and 0.166×10~(-2) ppm~2, respectively in the two cases of considering the effect of vinyl and vice versa. In this paper, we discuss the effects of model chain type, chain length and temperature on the bond probability. Meanwhile, it is pointed out that there exist a few cases, which are not in accord with the usual distrib
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| 关 键 词： | ~(13)C NMR semiempirical method complex system gauche arrangement γ effect. |
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