Activation - Driving Force Relationships in Radical Ion Rearrangements

本研究的重点是阐明有机自由基阴离子和阳离子的化学性质，这些阴离子和阳离子被认为是许多化学和生化转化的关键中间体。这些瞬态中间体的衰变速率，由选定的前驱体化学、电化学或光化学产生，将作为前驱体结构、溶剂极性和反离子的函数来测量。相应的热力学数据，主要是与环自由基阴离子和阳离子开环有关的自由能变化，将通过适当的热化学循环来电化学地确定。使用在实验过程中已经或将要合成的前体，并将相应的自由基阴离子或阳离子的动力学和热力学数据相关联，将开发这些短寿命中间体的结构-反应性关系。通过这个奖项，有机和大分子化学项目支持弗吉尼亚理工大学化学系James Tanko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，这种关系定义了活性阳离子和阴离子自由基中间体的化学性质。虽然在许多有机转化中被认为是中间体，但这些高活性、短寿命的中间体现在被认为是许多药理学和酶转化的中间体。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.