Chemical Applications of Vibrational Circular Dichroism Spectroscopy

南加州大学的Philip J. Stephens博士在振动圆二色光谱的化学应用方面的研究获得了化学学部物理化学项目的资助。Stephens博士将开发手性分子振动圆二色性（VCD）光谱的测量和预测的仪器和理论方法，并将应用VCD光谱来阐明手性分子的立体化学。为了减少偏振伪影和提高VCD仪器的灵敏度，将采用双调制方法。从头算DFT/GIAO预测振动旋转强度的方法将通过包含非调和性和溶剂效应而得到改进。应用将集中在确定绝对构型和构象分析。手性分子以两种形式存在——对映体——它们是镜像。药物分子对映体的不同生化行为导致了单对映体手性药物的不断发展。因此，有效表征手性分子结构的方法变得越来越重要。斯蒂芬斯博士将开发振动圆二色（VCD）光谱学方法，这是一种研究手性分子的技术。研究人员将开发新的方法来测量和预测VCD光谱，其精度将大大提高，这反过来将大大提高VCD光谱在手性分子，包括手性药物的结构表征中的应用。研究生和博士后将接受这些技术方面的培训。

Dr. Philip J. Stephens of the University of Southern California is funded for his research on chemical applications of vibrational circular dichroism spectroscopy by a grant in the Physical Chemistry program of the Chemistry Division. Dr. Stephens will develop instrumental and theoretical methods for the measurement and prediction of the vibrational circular dichroism (VCD) spectra of chiral molecules and will apply VCD spectroscopy to the elucidation of the stereochemistries of chiral molecules. A dual-modulation methodology will be implemented for the reduction of polarization artefacts and the enhancement of the sensitivity of VCD instrumentation. The ab initio DFT/GIAO methodology for predicting vibrational rotational strengths will be improved by inclusion of anharmonicity and solvent effects. Applications will focus on the determination of absolute configuration and conformational analysis.Chiral molecules exist in two forms - enantiomers - which are mirror images. The different biochemical behavior of enantiomers of a pharmaceutical molecule is leading to increasing development of single enantiomer, chiral drugs. Methods for efficiently characterizing the structures of chiral molecules are therefore of increasing importance. Dr. Stephens will develop the methodology of vibrational circular dichroism (VCD) spectroscopy, a technique for studying chiral molecules. New methods will be developed for measuring and predicting VCD spectra with much greater accuracy than heretofore possible, which in turn will greatly enhance the application of VCD spectrosopy to the structural characterization of chiral molecules, including chiral drugs. Graduate students and postdoctoral associates will be trained in these techniques.