Matrix isolation vibrational circular dichroism spectroscopic studies of chiral molecules and solvent effects.

几乎所有重要的生物分子都是手性的。事实上，生命的化学成分几乎完全建立在左旋氨基酸和右旋糖的基础上，这种模式被称为“生命的同手性”。药物通常是手性的，因为在许多情况下，只有具有正确手性的药物才能够在受体部位执行适当的“握手”。我们的研究重点是利用实验光谱和从头算方法来理解手性和手性识别现象。 目前，我们正在进行两个不同但相互关联的研究项目。一个是气相高分辨光谱研究手性分子团簇，另一个是凝聚相振动圆二色光谱研究。VCD光谱是近年来发展起来的一种测定手性分子绝对结构和构象结构的有效方法。然而，构象灵活的手性分子的VCD研究，经历严重的限制，因为它们的VCD光谱往往是广泛的，很少的功能，因为构象分布和溶质-溶剂相互作用。我们建议实施一个矩阵隔离组件到VCD光谱仪显着提高VCD光谱的灵敏度，多构象手性分子的调查。我们进一步建议使用矩阵隔离技术来制备小的溶质-溶剂簇VCD光谱研究，以探测溶质-溶剂分子间的相互作用，在一个逐步的方式。特别是，我们将研究如何手性，即VCD信号强度，被转移到一个非手性溶剂，如水，通过分子间的相互作用与手性分子。 结果将是显着的兴趣，谁实践合成有机化学，生物分析化学和环境化学的一大群化学家。拖延获得这一重要文书将使我们追求创新想法的努力受到严重挫折，并将妨碍我们领导这一令人兴奋的新领域并作出重大贡献的努力。

Nearly all important biological molecules are chiral. In fact, the chemistry of life is built almost exclusively on left-handed amino acids and right-handed sugars, a pattern known as the 'homochirality of life'. Pharmaceuticals are often chiral since in many cases only drugs with the correct handedness are capable of executing a proper 'hand shake' at the receptor site. Our research focuses on understanding the phenomena of chirality and chiral recognition using experimental spectroscopic and ab initio methods.     Presently, we are pursuing two distinct yet inter-linked research programs. One centers on the gas phase high resolution spectroscopy of chiral molecular clusters and the other one focuses on condensed phase studies using vibrational circular dichrosim (VCD) spectroscopy. VCD spectroscopy has emerged in recent years as a viable tool for the determination of absolute and conformational structures of chiral molecules. VCD studies of conformationally flexible chiral molecules, however, experience severe limitations since their VCD spectra tend to be broad and with few features because of conformational distributions and solute-solvent interactions. We propose to implement a matrix isolation assembly into the VCD spectrometer to significantly enhance the sensitivity of VCD spectroscopy for the investigations of multiconformational chiral molecules. We further propose to use matrix isolation technique to prepare small solute-solvent clusters for VCD spectroscopic studies in order to probe solute-solvent intermolecular interactions in a step wise manner. In particular, we will study how chirality, i.e.VCD signal strength, is transferred to an achiral solvent, such as water, through intermolecular interactions with a chiral molecule.      The results will be of significant interest to a large group of chemists who practice synthetic organic chemistry, bioanalytical chemistry, and environmental chemistry. A delay in obtaining this important instrument would be a severe setback for us to pursue our innovative idea and will hamper our efforts to lead and to contribute significantly to this exciting new field.