Green Chemistry, Absolute Kinetics, and Signal Amplification with Molecular Nanocrystals

化学结构、动力学和机制B项目支持加州大学洛杉矶分校的Miguel A.Garcia-Garibay教授利用单晶X射线衍射、固态核磁共振和激光闪光光解的化学动力学为固态反应建立可靠的反应性模型。大量的化学过程是在光的作用下发生的，在没有外部试剂的情况下，在固态环境的刚性约束下，化学键可以被打破，新的键可以形成。这类反应显示了与酶催化反应相竞争的化学控制水平。加西亚-加里巴伊教授团队的最新发展表明，尺寸约为200纳米的晶体是实现分析和工程应用的理想选择。该项目还研究了晶体中的量子链反应，其特征是每个吸收的光子形成一个以上的产物，信号放大值高达100万。该项目对绿色化学和可持续发展做出了关键贡献，它展示了利用悬浮在水中的纳米晶体样品，晶体中的反应可以扩大到数千公斤的规模。固体中的反应在各种情况下都很重要。这些问题包括固体药品和消费品的不良分解，结构固体的降解和老化，以及固态设备的疲劳。然而，这一建议最广泛的科学和技术影响是帮助发展所需的智力和人力基础设施，以了解固体中的反应，达到目前气相和溶液中常见的水平。这位研究人员通过保持高度支持和创造性的环境，促进了材料科学和科学教育的职业生涯，成功地吸引了女性和少数族裔学生加入他的研究小组。PI已经与贸易技术学院的教职员工建立了几个合作关系，该学院在洛杉矶市中心有非常多的西班牙裔和非裔美国人，这将鼓励他们的学生追求化学和材料科学的职业生涯。

The Chemical Structure, Dynamics and Mechanisms B Program supports Professor Miguel A. Garcia-Garibay of the University of California, Los Angeles to develop robust reactivity models for reactions in the solid state using single crystal X-ray diffraction, solid-state nuclear magnetic resonance, and chemical kinetics by laser flash photolysis. A large number of chemical processes occur with light, and in the absence of external reagents, chemical bonds can be broken and new bonds can be made under the rigid constraints of solid state environments. Such reactions display levels of chemical control that compete with those observed for reactions catalyzed by enzymes. Recent developments by Professor Garcia-Garibay's group have shown that crystals with sizes in the ca. 200 nm scale are ideal for the novel implementation of analytical and engineering applications. This project also investigates quantum chain reactions in crystals, characterized by the formation of more than one product per photon absorbed, with signal amplification values as high as one million. This project makes a key contribution to green chemistry and sustainability by demonstrating that reactions in crystals can be scaled up to multi-kilogram scales using nanocrystals samples suspended in water. Reactions in solids are important in a variety of circumstances. They include the undesirable decomposition of solid pharmaceuticals and consumer products, the degradation and aging of structural solids, and the fatigue of solid state devices. However, the broadest scientific and technological impact of this proposal is to help develop the intellectual and human infrastructure needed to understand reactions in solids at a level now common for the gas phase and in solution. The investigator has been successful attracting women and minority students to his research group by maintaining a highly supportive and creative environment that fosters careers in materials science and in science education. The PI has established several collaborations with faculty at Trade Technical College, which has a very large Hispanic and African American population in downtown Los Angeles, and which will encourage their students to pursue careers in chemistry and materials science.