Synthesis and Study of Non-Kekule Molecules

非凯库勒分子的合成与研究

基本信息

批准号：
9321241
负责人：
Joseph Grabowski
金额：
$ 30.5万
依托单位：
University of Pittsburgh
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1994
资助国家：
美国
起止时间：
1994-01-01 至 1997-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9321241&HistoricalAwards=false
关键词：
Synthesis Study Non Kekule Molecules

项目摘要

This proposal requests funds to examine a series of disjoint biradicals by chemical and spectroscopic methods. Molecular orbital calculations have predicted that disjoint biradicals will possess a singlet ground state. Previous work from this laboratory has resulted in finding a triplet ground state disjoint biradical. This contradiction of theory will be pursued further with new examples which have rigidly defined structures for comparison to theoretical calculations. Non-alternant biradicals will be explored, which contain in some fashion, cyclopentadiene rings. The interplay between structure and multiplicity of these biradicals will be explored, where lower membered systems are expected to be singlets and higher membered systems triplets. This grant from the Organic Dynamics Program supports the continuing work of Professor Paul Dowd at the University of Pittsburgh. The chemical and spectroscopic properties of a novel series of reactive intermediates known as biradicals will be examined. Biradicals are molecules where there are an odd number of electron at two sites. For example, in a hydrocarbon biradical, two carbon atoms will each be bonded to three other carbon atoms and have one unbonded electron. The two odd electrons may have spins paired (a singlet) or unpaired (a triplet). The lowest energy states (singlet or triplet) of the biradicals will be determined experimentally as a function of structure. These results will be compared to theoretical calculations.

该提案要求提供资金，通过化学和光谱方法检查一系列不相交的双自由基。分子轨道计算预测不相交的双自由基将具有单线态基态。该实验室之前的工作已经发现了三重态基态不相交的双自由基。我们将通过新的例子进一步探讨这种理论矛盾，这些例子具有严格定义的结构，以便与理论计算进行比较。将探索非交替双自由基，其以某种方式包含环戊二烯环。将探讨这些双自由基的结构和多重性之间的相互作用，其中较低元系统预计为单线态，较高元系统预计为三元组。有机动力学计划的这笔赠款支持匹兹堡大学保罗·多德教授的持续工作。将检查一系列称为双自由基的新型反应中间体的化学和光谱特性。双自由基是在两个位点上有奇数个电子的分子。例如，在烃双基中，两个碳原子将分别与其他三个碳原子键合，并具有一个未键合的电子。两个奇数电子的自旋可能是成对的（单线态）或不成对的（三线态）。双自由基的最低能态（单线态或三线态）将通过实验确定为结构的函数。这些结果将与理论计算进行比较。