Anion-pi and halogen-bonded complexes in thermal and photochemical reactions

鲍尔州立大学的Sergiy Rosokha教授得到化学系大分子、超分子和纳米化学计划的支持，研究分子之间的弱相互作用力及其在需要热能或光能形成产品的化学反应中的作用。研究中的特殊非键相互作用(阴离子-pi键和卤素键)使分子能够在精细的超分子结构中聚集。该项目帮助确定了将非键相互作用有效地纳入分子设计的要求，产生了一种新的工具，用于从带电和卤化分子中更有效和对环境友好地合成独特的化学品，这些分子普遍存在于生物系统和环境中。该项目预计将影响许多领域，如药物开发、环境修复和材料开发。该项目的跨学科性质为一个以本科为主的机构的不同本科生群体提供了各种现代实验化学研究技术以及计算化学的培训。该项目基于Rosokha教授最近的发现，即除了控制超分子络合物的结构外，阴离子-和卤素键还促进相互作用物种之间的电子移动，这可以引发各种化学转化。该项目的具体目标是确定和表征经历热或光诱导反应(例如，卤素和/或电子转移、亲核取代等)的体系中的卤素键和阴离子-PI络合物。并确定这些络合物在此类反应中的机理作用。为了实现这些目标，研究了阴离子-PI或卤素键合络合物的形成以及键合物种之间的化学反应或光化学反应的体系。利用低温停流紫外可见光谱和X射线结构分析对该体系中的瞬时络合物进行了分离和表征。结合热和光诱导反应动力学的测量以及计算分析，这使得能够确定中间络合物的性质及其在反应机理中的作用。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Professor Sergiy Rosokha of Ball State University is supported by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry to study weak interaction forces between molecules and their role in chemical reactions that need heat or light energy to form products. The specific non-bonding interactions under study (anion-pi and halogen bonding) enable the aggregation of molecules in elaborate supramolecular structures. The project helps define the requirements to efficiently incorporate the non-bonding interactions into molecular design, producing a new tool for more efficient and environmentally benign synthetic procedures for unique chemicals from charged and halogenated molecules, which are ubiquitous in biological systems and the environment. The project is expected to impact many fields, such as drug development, environmental remediation and materials development. The interdisciplinary nature of the project provides a diverse group of undergraduate students in a primarily undergraduate institution with training in a variety of modern experimental chemistry research techniques, as well as computational chemistry. The project builds on the recent findings by Professor Rosokha that, in addition to controlling the structures of supramolecular complexes, anion- and halogen bonding facilitate electron movement between interacting species, which can initiate a variety of chemical transformations. The specific objectives of the project are to identify and characterize halogen bonding and anion-pi complexes in the systems undergoing thermal or light-induced reactions (e.g., halogen and/or electron transfer, nucleophilic substitution, etc.) and to determine the mechanistic role of these complexes in such reactions. To achieve these objectives, the systems in which formation of anion-pi or halogen-bonded complexes is followed by the chemical or photochemical reactions between bonded species, are studied. Transient complexes in such systems are isolated and characterized using low-temperature and stopped-flow UV-Vis measurements and X-ray structural analysis. Together with the measurements of the kinetics of thermal and light-induced reactions, as well as computational analysis, this allows to establish the nature of the intermediate complexes and their role in the reaction mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.