有机化合物碳-氢“clumped”同位素平衡分馏参数的理论研究

项目名称： 有机化合物碳-氢“clumped”同位素平衡分馏参数的理论研究

项目编号： No.41203020

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 地球化学

项目作者： 刘琪

作者单位： 中国科学院地球化学研究所

项目金额： 25万元

中文摘要： 近年来，基于碳酸盐碳-氧"clumped"同位素建立起的地温测试技术凭借其独特的优势已逐渐应用于越来越多的地学领域。"Clumped"同位素一旦拓展到其他研究体系无疑会为地学研究带来更多的收益。最近，加州理工大学John Eiler教授已协同加州大学洛杉矶分校的Edward Young教授开始筹建有机体系碳-氢"clumped"同位素实验室。然而，若要该技术在地学领域成功应用，首先需要了解有机分子"clumped"同位素的平衡分馏信号。理论计算便是了解这一信息的有效方法。由于碳-氢"clumped"同位素的分析测试精度要求高，同时还涉及到氢同位素交换，故"clumped"同位素平衡分馏信号的理论预测需要非谐层面的精确计算。由于申请人在此方向有丰富的工作经验，故申请以超越简谐水平的计算方法预测有机分子碳-氢"clumped"同位素的温度依赖性，为未来的实验学研究提供理论层面的参考和指导。

中文关键词： 稳定同位素；“Clumped”同位素；同位素分馏；量子化学计算；非谐

英文摘要： In recent year, carbonate clumped isotope thermometry has found increasing applications of geosciences. It is expected that the clumped isotope technique can also play a positive role in the study of other isotope systems. Recently, Prof. John Eiler in Caltech collaborated with Prof. Edward Young in UCLA works to build a C-H clumped isotope laboratory for studying organic compounds. However, the C-H clumped isotope fractionation signatures should be known before this technology works for geosciences. One effective way to understand that information is to calculate it theoretically. Because extremely high accuracy is required for clumped isotope study and C-H clumped isotope study refers to hydrogen isotope exchanges, prediction of C-H clumped isotope fractioantions needs theoretical calculation beyond harmonic level. Because the applicant has enormous experience in such calculation, this proposal is made to study the temperature dependency of C-H clumped isotope signatures for organic compounds beyond harmonic level to give a spark for the future experimental operation.

英文关键词： Stable isotope；Clumped isotope；Isotope fractionation；Quantum chemistry calculation；Anharmonicity