波谱学杂志2001，Vol.18Issue(2)：135-141,7.
量子化学计算辅助聚（N-异丙基丙烯酰胺） 溶液碳谱的归属
13C HIGH-RESOLUTION SPECTRUM OF POLY(N-ISOPROPYLACRYLAMIDE) AS ASSIGNED WITH THE AID OF GAUSSIAN98 QUANTUM CHEMICAL CALCULATION
摘要
Abstract
The quantitative 13C high resolution NMR spectrum of poly(N-isopropylacrylamide) (PNIPAAM) was assigned with the aid of Gaussian98 calculation. Two methods, γ-gauche effect and ab initio calculation, have been applied to calculate the 13C NMR chemical shifts of stereosequences of PNIPAAM. The parameters for γ-gauche effect were developed from the ab initio calculations of diads. The basis set used was 6-31G*, and the method was GIAO-CHF. For ab initio calculation, all geometries were optimized via AM1 method and the 13C NMR chemical shifts were calculated via GIAO-CHF method with STO-3G basis set. Stereosequences to triad level were considered for the methine carbon of main chain, while for the methylene and methyl carbons, stereosequences to tetrad and pentad level were considered respectively. It was found that the ab initio calculation can well reproduce the observed 13C NMR spectrum, while the γ-gauche effect method failed to give satisfactory result. Thus, based on the result of ab initio calculation, the signals of methine carbons, methylene carbon and methyl carbon were assigned and the tacticity of PNIPAAM was turn out to be random. As a result, the ab initio calculation was proved to be an effective method to investigate the tacticities of macromolecules.关键词
聚（N-异丙基丙烯酰胺）/立构规整度/化学位移计算分类
化学化工引用本文复制引用
刘松柏,陈群,杨光,严晓虎..量子化学计算辅助聚（N-异丙基丙烯酰胺） 溶液碳谱的归属[J].波谱学杂志,2001,18(2):135-141,7.基金项目
教育部全国高校百名优秀青年教师教学 （）
