HBCU Excellence in Research: Research and Education Center for Investigation of Chemical Transformations in Host-Guest Systems at Extreme Conditions

在化学系化学结构、动力学和机理a （CSDM-A）项目和综合活动办公室（OIA）的支持下，霍华德大学的Mohammad Mahmood教授和华盛顿卡内基研究所的Alexander Goncharov博士将使用同步加速器和自由电子激光x射线衍射、拉曼、和光谱学来研究主客体化合物，重点是在极端高压和高温条件下的C-N-O-H相图。这项工作旨在解决与理解分子材料和主客体系统对高压和高温极端条件的响应以及它们在这些条件下的化学反应性和转化相关的挑战。这项研究是一项与地球和行星科学相关的物理化学研究，因为关于分子和主客体化合物的结构、组成和稳定性的信息可以用来解决与行星内部有关的各种问题。此外，这项活动将使来自代表性不足群体的有才华的年轻科学家有可能在霍华德大学和卡内基研究所共同监督下的学术环境中接受培训，为他们将来从事科学事业做好准备。拟议的研究计划将集中在高压和极端温度（P-T）极端条件下的物质研究。重点将放在主客系统上；这两个水笼宿主包含各种客体分子和共晶系统将被研究。这些系统的特点是具有丰富的物理和化学现象，特别是在极端温度和压力的条件下。这具有额外的相关性，因为其中一些系统被认为是行星内部的组成部分。Mahmood教授和Goncharov博士及其团队，包括博士后助理、研究生和本科生，将研究这些系统的结构、组成和振动特性，以及它们的物理和化学转变作为压力和温度的函数。在这样做的过程中，该团队渴望建立这些系统与高温超导等新兴现象之间的潜在联系。实验将涉及最先进的衍射和光谱技术，包括同步加速器和XFEL衍射，以及用金刚石砧细胞进行的拉曼光谱和光学光谱。由于这些研究，预计将对极端条件下主客体复合物的化学和物理有更好的了解。该奖项反映了美国国家科学基金会的法定使命，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 support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) program in the Division of Chemistry and the Office of Integrative Activities (OIA), Professor Mohammad Mahmood of Howard University and Dr. Alexander Goncharov of Carnegie Institution of Washington will use synchrotron and free electron laser X-ray diffraction, Raman, and optical spectroscopy to study host-guest compounds with a focus on C-N-O-H phase diagrams under extreme conditions of high pressures and temperatures. This work is intended to address the challenges associated with understanding the response of molecular materials and host-guest systems to the extreme conditions of high pressure and temperature and their chemical reactivity and transformations at these conditions. This research is a physical chemical study of relevance to earth, and planetary science as information about the structure, composition and stability of molecular and host-guest compounds can be used to address a variety of questions related to planetary interiors. Furthermore, this activity will open a possibility for the talented young scientists from underrepresented groups to be trained in an academic environment under combined supervision at Howard University and the Carnegie Institution to prepare them for potential careers in science.The proposed research program will be centered on investigations of matter under extreme conditions of high pressure and extreme temperatures (P-T). The focus will be on host-guest systems; both water cages hosts containing various guest molecules and co-crystalline systems will be studied. These systems are characterized by a wealth of physical and chemical phenomena, particularly under conditions of extreme temperature and pressure. This takes on additional relevance as some of these systems are thought to be components of planetary interiors. Professor Mahmood and Dr. Goncharov and their team including postdoctoral associates and graduate and undergraduate students will investigate the structure, composition and vibrational properties of these systems, as well as their physical and chemical transformations as a function of pressure and temperature. In so doing, the team aspires to establish potential connections of these systems with emergent phenomena such as high-temperature superconductivity. The experiments will involve state-of-the-art diffraction and spectroscopic techniques including synchrotron and XFEL diffraction, and Raman and optical spectroscopy performed with diamond anvil cells. As a result of these studies, it is anticipated that a better understanding of the chemistry and physics of host-guest complexes under extreme conditions will be developed.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.