Molecular Solvation Phenomena in Nanoscale Superfluids

纳米级超流体中的分子溶剂化现象

• 批准号: 0107541
• 负责人: K. Birgitta Whaley
• 金额: $ 37.5万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0107541&HistoricalAwards=false
• 关键词: Molecular; Solvation; Phenomena; Nanoscale; Superfluids

Birgitta Whaley of the University of California, Berkeley, is supported by the Theoretical and Computational Chemistry Program to carry out microscopic theoretical analysis of two classes of novel quantum solvation phenomena that have been revealed by recent spectroscopic experiments, which remain theoretically unexplained. The aim is to uncover the role played by the underlying quantum structure and dynamics in the spectroscopic observables. The first phenomenon to be explored concerns the effect of "wrapping" a molecule with the solvation layer of molecular para-hydrogen and then embedding this in a helium cluster at ultra-low temperatures. The extent of nanosuperfluidity possible in the hydrogen and solvation wrap will be analyzed, along with the relation between the quantum statistics of this and the molecular spectroscopic constants. Secondly, helium solvent-induced modifications of structure and excitations of embedded molecules and complexes will be addressed, focusing on intramolecular tunneling, structures of heterocomplexes, and on the nature of the local solvation environment and associated solvent excitations around planar organic molecules. This research involves application of large-scale quantum simulation methodology, algorithmic advances in some cases, and a combination of simulations with theoretical analysis using dynamical models. Small liquid clusters of helium that are produced in molecular beam expansions are becoming an increasingly popular new medium in which atoms and molecules can be embedded and studied experimentally. The clusters act as novel environments in which to examine ultra-low temperature properties of molecules, chemical reactions, and the energies of solvation. The outcomes of this project are expected to lead to new insights into the fundamental understanding of chemical and physical behavior in cold quantum mechanical solvents.

加州大学伯克利分校的Birgitta Whaley在理论和计算化学计划的支持下，对最近光谱实验揭示的两类新的量子溶剂化现象进行了微观理论分析，这些现象在理论上仍未得到解释。其目的是揭示光谱观测中潜在的量子结构和动力学所起的作用。要探索的第一个现象涉及到用分子对氢分子的溶剂化层“包裹”分子，然后在超低温下将其嵌入氦团簇中的效果。将分析在氢和溶剂化包裹中可能的纳米超流动性的程度，以及这种超流动性的量子统计与分子光谱常数之间的关系。其次，将讨论氦溶剂对嵌入分子和络合物的结构和激发的影响，重点讨论分子内隧穿、杂化络合物的结构，以及平面有机分子周围局部溶剂化环境的性质和相关的溶剂激发。这项研究涉及大规模量子模拟方法的应用，在某些情况下的算法进展，以及使用动力学模型进行模拟与理论分析相结合。在分子束膨胀过程中产生的微小液氦团簇正成为一种越来越受欢迎的新介质，可以在其中嵌入原子和分子并进行实验研究。这些团簇作为新的环境，在其中研究分子的超低温性质、化学反应和溶剂化能。该项目的结果有望导致对冷量子力学溶剂中化学和物理行为的基本理解的新见解。