Biradical-like Reactive Intermediates

9318469 Michl将探索几个不同的研究领域。双基类分子的单重态-三重态能隙将由矩阵隔离电子能量损失谱（EELS）测定。通过键对自旋轨道耦合的贡献，利用分子轨道理论分析了饱和自由基和双自由基中自旋密度离域的机理。将在基质分离条件下制备新的全氟双自由基样物质，并探索在基质中进行选择性反应的新方法。环丁二烯的两个凯库勒结构之间的自动机也将被研究。这些结果将为反应中间体的化学键和性质以及它们在热化学和光化学反应中的作用提供新的认识。来自有机动力学计划的这笔拨款支持科罗拉多大学约瑟夫·米歇尔教授的持续研究。正常情况下，碳总共有4个其他原子和电子对。碳自由基是典型的反应性中间产物，总共有三个其他原子和一对电子加上一个额外的电子。含有一个和两个自由基位点的物质将在低温下用复杂的光谱方法进行研究。将讨论两个自由基位点之间的相互作用。这些物质的结构和能量的计算也将进行，以补充实验结果。这些结果将对反应中间体的键和性质及其在热反应和光引发反应中的作用提供新的认识。* * *

9318469 Michl Several different areas of research will be explored. Singlet-triplet energy gaps of biradical-like molecules will be determined by matrix-isolation electron energy loss spectroscopy (EELS). Through bond contributions to spin- orbit coupling and the mechanisms of spin density delocalization in saturated radicals and biradicals using molecular orbital theory will be analyzed. New perfluorinated biradical-like species will be prepared under conditions of matrix-isolation and a new approach to selective reactions in matrices will be explored. Automerization between the two Kekule structures of cyclobutadiene will be investigated as well. The results will provide new understanding of the chemical bonding and properties of reactive intermediates, and the role they play in thermal and photochemical reactions. %%% This grant from the Organic Dynamics Program supports the continuing research of Professor Josef Michl at the University of Colorado. Normally, there are a total of four other atoms and pairs of electrons associated with carbon. Carbon radicals are typically reactive intermediates and have a total of three other atoms and pairs of electrons plus one additional electron. Species containing one and two radical sites will be studied by sophisticated spectroscopic methods at low temperatures. Interactions between the two radical sites will be addressed. Calculations of the structure and energy of these species will be carried out as well to complement the experimental results. These results will provide a new understanding of bonding and properties of reactive intermediates, and their role in thermal and photo-initiated reactions. ***