ADVANCED ROTATIONAL ISOMERIC STATE SCHEME FOR MOLECULAR DESIGN OF ORGANIC AND POLMYERIC MATERIALS

在本计画中，我们透过以下三个主题，发展出一个先进的旋转异构态（RIS）架构，以进行有机及高分子材料的分子设计。(1)合成了六种不同构型的聚环氧丙烷二聚体模型化合物，用~（13）C NMR研究了它们的化学位移，并用RIS方案结合取代基效应很好地再现了实验结果。理论和实验之间的协议表明，在计算中使用的构象能的有效性，分子内（C-H）... O吸引力的存在下，和化学位移评价的RIS计划的适用性。(2)用静态光散射和尺寸排阻色谱-多通道激光光散射法研究了聚甲基正丙基硅烷、聚二正丁基硅烷和聚二正己基硅烷的无扰链尺寸。对于单个聚合物，构象能，包括主链和侧链的相互作用，从分子动力学模拟确定。所观察到的特征比率，以及再现RIS计划使用的构象能，从而确定。因此，我们已经开发了一种方法的构象分析的聚合物与长侧链。(3)研究了链状分子如正构烷烃和醚类分子溶解在水溶性溶剂中的构象和取向特征，以及两亲分子在六方、层状和反六方聚集体中的构象和取向特征。采用RIS方案和最大熵方法相结合的方法，模拟了氘核磁共振四极分裂和质子-质子偶极耦合。我们建立了一种在各向异性场中分析链状分子构象的方法。

In this project, we have developed an advanced rotational isomeric state (RIS) scheme for molecular design of organic and polymeric materials through the following three subjects.(1) Six dimeric model compounds of poly (propylene oxide), having different configurational sequences, were prepared, and investigated by carbon-13 NMR.The observed chemical shifts, assigned experimentally to the component carbon atoms, were well reproduced by the RIS scheme combined with substituent effects. The agreement between theory and experiment shows the validity of the conformational energies used in the calculations, the presence of the intramolecular (C-H)…O attraction, and the applicability of the RIS scheme to chemical-shift evaluation.(2) Unperturbed chain dimensions of poly (methyl n-propylsilane), poly (di-n-butylsilane), and poly (di-n-hexylsilane) were evaluated by static light scattering and size-exclusion chromatography-multichannel laser light scattering. For individual polymers, conformational energies including interactions of both main and side chains were determined from molecular dynamics simulations. The observed characteristic ratios were well reproduced by the RIS scheme using the conformational energies thus determined. Thus, we have developed a method for conformational analysis of polymers with long side chains.(3) Conformational and orientational characteristics of chain molecules such as n-alkanes and ethers dissolved in nematic solvents and amphiphilic molecules incorporated in hexagonal, lamellar, and reversed hexagonal aggregates have been investigated. Deuterium NMR quadrupolar splittings and proton-proton dipolar couplings were simulated by a combined use of the RIS scheme and the maximum entropy method. We have established a methodology for conformational analysis of chain molecules in anisotropic fields.