Laser Spectroscopy of Ions and Clusters

离子和团簇的激光光谱

• 批准号: 9727302
• 负责人: Richard Saykally
• 金额: $ 108万
• 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: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2001-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9727302&HistoricalAwards=false
• 关键词: Laser; Spectroscopy; Ions; Clusters

Richard J. Saykally of the University of California in Berkeley is supported by the Experimental Physical Chemistry Program in his continuing studies of clusters using infrared spectroscopy. The goal is to determine structure, force fields and hydrogen bond network rearrangements in water clusters (hexamer, octamer and larger) using far infrared (FIR) laser vibration-rotation-tunneling (VRT) spectroscopy or infrared-cavity ring down laser absorption spectroscopy (IR-CRLAS). A water-water pair potential will be derived from analysis of the dimer spectra, and an effective potential for the larger clusters and liquid water will be constructed. Prof. Saykally will also investigate intermolecular dynamics of nucleotide bases and their hydrated clusters. To support these studies, a number of technological advances are planned including extension of the CRLAS deeper into the mid-IR and development of a new FIR laser with a ring cavity design. Establishing a detailed and quantitative understanding of liquid water continues to be a problem of major importance. While the intriguing properties of supercooled water and hydrophobic interactions occupy the interest of many prominent chemists and physicists, the more mundane problem of accurately describing the ordinary liquid over a wide range of temperatures is of considerable practical importance. This project will enhance our understanding of the liquid and solid phases of water by examining successively larger clusters one molecule at a time, and studying these clusters in great detail with new laser technology and state-of-the-art theoretical methods. The resulting data will ultimately provide a more detailed description of the important many body forces operating in the liquid. The newer effort involving studies of hydrogen bonding of water with nucleotide bases is clearly of fundamental significance in biology.

加州大学伯克利分校的理查德·J·赛卡利 (Richard J. Saykally) 在实验物理化学项目的支持下，继续使用红外光谱对星团进行研究。 目标是使用远红外 (FIR) 激光振动旋转隧道 (VRT) 光谱或红外腔环降激光吸收光谱 (IR-CRLAS) 确定水簇（六聚体、八聚体和更大）的结构、力场和氢键网络重排。 水-水对电势将从二聚体光谱的分析中得出，并且将构建较大簇和液态水的有效电势。 Saykally 教授还将研究核苷酸碱基及其水合簇的分子间动力学。 为了支持这些研究，计划进行一些技术进步，包括将 CRLAS 扩展到中红外更深处，以及开发具有环形腔设计的新型 FIR 激光器。 对液态水建立详细和定量的了解仍然是一个非常重要的问题。 虽然过冷水和疏水相互作用的有趣特性引起了许多著名化学家和物理学家的兴趣，但在广泛的温度范围内准确描述普通液体的更平凡的问题具有相当大的实际重要性。 该项目将通过一次一个分子连续检查更大的簇，并利用新的激光技术和最先进的理论方法详细研究这些簇，来增强我们对水的液相和固相的理解。 所得数据最终将提供对在液体中作用的许多重要的体积力的更详细的描述。 涉及水与核苷酸碱基氢键研究的最新成果显然在生物学中具有根本意义。