Synthesis and Study of Non-Kekule Molecules

这项提案要求资金来研究一系列不相交的双自由基 通过化学和光谱学方法。分子轨道计算 我曾预言，不相交的双自由基将拥有一个单线态基 状态该实验室以前的工作已经发现了一种 三重基态不相交双自由基。这种理论上的矛盾 将进一步探讨新的例子，这些例子已经严格定义 与理论计算结果进行比较。非交替的 将探索双自由基，其以某种方式包含， 环戊二烯环。结构与多样性之间的相互作用 将探讨这些双自由基，其中低元系统是 预计是单线态和更高元的系统三重态。 有机动力学项目的资助支持了 匹兹堡大学的保罗·多德教授化学和 一系列新型活性中间体的光谱性质 称为双自由基。双自由基分子 在两个位置有奇数个电子。例如以 在烃双自由基中，两个碳原子将各自键合到三个 有一个未键合的电子。这两个奇电子 可能有成对的自旋（单线态）或不成对的自旋（三线态）。最低 双自由基的能态（单重态或三重态）将被确定 实验上是结构的函数。这些结果将被比较 理论计算。

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.