Collaborative Research: Photocatalytic Ketyl and Amino Radicals-Initiated C-C Bond Formation via Semiconductor-Based Photocatalysts

开发经济有效的碳-碳键形成方法在化学工业中发挥着重要作用。许多传统的策略都是基于被称为催化剂的复杂分子发明的。已知催化剂的一个常见且持久的局限性是它们价格昂贵、效率低下，并产生不想要的副产品作为废物。遵循绿色化学的原则，辛辛那提大学的孙玉杰博士和普渡大学的廖培林博士在化学催化计划的资助下，共同为这些重要的转化设计和开发改进的催化剂。他们的协同实验和计算项目正在解决使用光作为能源来驱动使用光催化剂的碳-碳键形成反应所需的基础科学。孙博士正在开发一门新的绿色化学课程，面向在化学背景下具有可持续发展广泛背景的本科生。Sun集团还积极参与了辛辛那提大学的许多外展项目，包括加州大学社区日开放日、辛辛那提博物馆中心的加州大学化学夏令营、加州大学田野研究中心的科学日，面向K-12年级学生和普通公众的科学日。廖博士的团队参与了普渡大学的推广项目，如普渡纳米日和普渡大学本科生暑期研究奖学金项目。在化学系化学催化项目的资助下，辛辛那提大学的孙玉杰博士和普渡大学的廖培林博士正在开发一种新的合成方法，在半导体基光催化剂上进行C-C偶联反应。合成、表征和系统研究了硫化镉、硫化锌和氮化碳纳米片等超薄半导体光催化体系在可见光照射下对羰基、醇、胺和亚胺的C-C偶联反应。通过调节目标半导体的形貌和能带结构，匹配有机衬底的氧化还原电位，在半导体表面附近产生酮基和氨基，它们很容易偶联，实现所需的C-C键形成。应该强调的是，这种策略利用了激发电子和空穴，最大限度地提高了光催化的能量效率，并避免了牺牲试剂的必要性。在密度泛函计算的辅助下，该项目涵盖了固态合成、材料表征、光解研究、同位素和电子效应研究以及动力学分析，从大范围底物的同质耦合到复杂的交叉耦合的模型系统开始。孙博士和廖博士都积极参与STEM外展项目，重点关注未被充分代表的学生和普通公众，以支持该项目的更广泛影响。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。

The development of economic and efficient methods to form carbon-carbon bonds is an important role in the chemical industry. Many traditional strategies have been invented based on sophisticated molecules known as catalysts. A common and persisting limitation of known catalysts is that they are expensive, inefficient, and generate unwanted byproducts as waste. Following the principles of green chemistry Dr. Yujie Sun from University of Cincinnati and Dr. Peilin Liao from Purdue University, with funding from the Chemical Catalysis Program, are collaborating to design and develop improved catalysts for these important transformations. Their synergistic experimental and computational project is addressing the fundamental science needed to use light as the energy source to drive carbon-carbon bond forming reactions using photocatalysts. Dr. Sun is developing a new course in Green Chemistry to undergraduates a broad background of sustainability in the context of chemistry. The Sun group is also actively involved in many outreach programs at University of Cincinnati, including UC Community Day Open House, UC-Chem Summer Camp at Cincinnati Museum Center, Science Day at the UC Center for Field Studies for K-12 grade students and the general public. Dr. Liao’s group is involved in outreach programs at Purdue University, such as Purdue NanoDays and the Purdue Summer Undergraduate Research Fellowship Program.With funding from the Chemical Catalysis Program of the Division of Chemistry, Dr. Yujie Sun of the University of Cincinnati and Dr. Peilin Liao of Purdue University are developing a novel synthetic approach to C-C coupling reactions on semiconductor-based photocatalysts. Ultrathin semiconductor-based photocatalytic systems, including CdS, ZnIn2S4, and CNx nanosheets, are synthesized, characterized, and systematically investigated for the C-C coupling reactions of carbonyls, alcohols, amines, and imines under visible light irradiation. By modulating the morphology and band structures of targeted semiconductors and matching the redox potentials of organic substrates, ketyl and amino radicals are produced in proximity on the semiconductor surface, which readily couple to accomplish the desired C-C bond formation. It should be emphasized that this strategy utilizes both excited electrons and holes, maximizing the energy efficiency of photocatalysis and circumventing the necessity of sacrificial reagents. Assisted by DFT computations, this project encompasses solid-state synthesis, materials characterization, photolysis investigation, isotope and electronic effects study, and kinetic analysis, starting from model systems for homo-coupling to complex cross-coupling of a broad scope of substrates. Both Dr. Sun and Dr. Liao are actively engaged in STEM outreach programs focused on underrepresented students and the general public, in support of the broader impacts of this project.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.