Developing a Conceptual Framework for the Rare Dual-release Photochemistry of Sulfoximines and Sulfondiimines.

圣刘易斯大学化学系的Ryan McCulla教授将在化学系的化学结构、动力学机制-B（CSDM-B）计划的支持下，研究磺酰亚胺和磺酰二亚胺的光化学，这两种化合物在光照下能够释放两种不同的活性中间体。本研究的目的是建立一般原则，管理的顺序由亚砜亚胺和磺酰亚胺的反应中间体的光释放。磺酰亚胺是少数几类能够进行双重释放光化学的化合物之一，该项目预计将确定哪些属性调节释放顺序。通过提供控制光释放顺序的基础，该项目有望促进用于生化测定和光疗的双释放光化学的发展。暑期研究机会和活动，促进来自代表性不足的群体的高中生的科学职业选择也将是资助项目的一部分。从一个单一的发色团产生两种不同的活性中间体是一种罕见的光化学发生。少数几个例子之一是二苯并噻吩亚砜亚胺在光照射下释放氮烯和原子氧。能够进行双释放光化学的系统的稀缺性意味着没有概念框架来预测哪些属性将控制释放的顺序。因此，本项目的总体目标是通过研究噻吩基亚砜亚胺的光化学来建立双释放光化学的一般原则。具体而言，调制的键离解能和激发态的性质上的顺序释放的影响将询问与计算和光谱方法。本提案的第二个重要目标是通过检查观察到的亚砜亚胺的原则是否可以预测磺酰亚胺的释放顺序，来测试拟议框架的一般性。双释放光化学的诱人潜力来自于两种活性中间体可以产生的接近性，这有望使两种瞬时中间体联合收割机形成其他方法无法获得的新中间体。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemical Structure, Dynamics & Mechanisms-B (CSDM-B) Program of the Chemistry Division, Professor Ryan McCulla of the Department of Chemistry at Saint Louis University will investigate the photochemistry of sulfoximines and sulfondiimines which are capable of releasing two different reactive intermediates upon irradiation with light. The goal of this research is to establish general principles that govern the sequence of photorelease of reactive intermediates by sulfoximines and sulfondiimines. Sulfoximines are one of the few classes of compounds that are capable of undergoing dual-release photochemistry, and this project is expected to establish which properties regulate the sequence of release. By providing a basis to control the sequence of photorelease, this project is expected to facilitate the development of dual-release photochemistry for uses in biochemical assays and phototherapies. Summer research opportunities and events promoting scientific career options for high school students from underrepresented groups will also be part of the funded project.The generation of two different reactive intermediates from a single chromophore is a rare occurrence in photochemistry. One of the few examples is the release of nitrenes and atomic oxygen from dibenzothiophene sulfoximines upon irradiation with light. The scarcity of systems capable of undergoing dual-release photochemistry means there is no conceptual framework to predict which properties will control the sequence of release. Thus, the overall objective of this project is to establish the general principles that govern dual-release photochemistry by investigating the photochemistry of thiophene-based sulfoximines. Specifically, the effect of modulating the bond dissociation energies and the excited state properties on the sequence of release will be interrogated with computational and spectroscopic methods. The second important objective of this proposal is to test the generality of the proposed framework by examining if the principles observed for sulfoximines can predict the sequence of release for sulfondiimines. The intriguing potential of dual-release photochemistry arises from the proximity that two reactive intermediates can be produced, which is expected to allow two transient intermediates to combine to form new intermediates that are inaccessible by other means.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.