Activation - Driving Force Relationships in Radical Ion Rearrangements

这项研究集中于阐明有机自由基阴离子和阳离子的化学，这些阴阳离子被认为是许多化学和生化转化的关键中间体。这些以化学、电化学或光化学方法从选定的前体产生的暂态中间体的衰变速度将作为前体结构、溶剂极性和反离子的函数进行测量。相应的热力学数据，主要是与环状自由基阴阳离子开环有关的自由能变化，将通过适当的热化学循环以电化学的方式确定。使用在实验过程中已经或将要合成的选定前体，并将获得的相应自由基阴离子或阳离子的动力学和热力学数据进行关联，将建立这些短寿命中间体的结构-反应性关系。通过这个奖项，有机和高分子化学项目支持弗吉尼亚理工大学化学系詹姆斯·坦科教授的研究和教育活动。Tanko教授的研究将集中于阐明结构-反应性关系，这些关系定义了反应性阳离子和阴离子自由基中间体的化学。虽然众所周知，这些高活性、寿命短的中间体在许多有机转化中是中间体，但现在被认为是一些药理和酶转化中的中间体。Tanko教授的教育活动涉及博士后、研究生和本科生的教育和培训。

This research focuses on elucidating the chemistry of organic radical anions and cations that are considered to be key intermediates in a number of chemical and biochemical transformations. The rates of decay of these transient intermediates, generated chemically, electrochemically, or photochemically from selected precursors, will be measured as functions of precursor structure, solvent polarity and counter ion. Corresponding thermodynamic data, principally the free energy change associated with the ring opening of cyclic radical anions and cations, will be determined electrochemically by means of appropriate thermochemical cycles. Using selected precursors that have been or will be synthesized during the course of the experiments, and correlating the kinetic and thermodynamic data obtained for the corresponding radical anion or cation, structure-reactivity relationships of these short-lived intermediates will be developed. With this Award, the Organic and Macromolecular Chemistry Program supports the research and educational activities of Professor James Tanko of the Chemistry Department at Virginia Polytechnic University. Professor Tanko's research will focus on elucidating the structure-reactivity relationships that define the chemistry of reactive cationic and anionic radical intermediates. Although well known as intermediates in a number of organic transformations, these highly-reactive, short-lived intermediates are now thought to be intermediates in a number of pharmacological and enzymatic transformations. Professor Tanko's educational activities involve the education and training of postdoctoral, graduate and undergraduate students.