Vibrational dynamics of the acid-alcohol hinge

有机醇和有机酸的特性非常好，特别是关于它们的配对趋势。前者经历中等强度，良好的特征氢键，而羧酸之间的氢键显着更强，酸性质子的振动动力学变得不规则。科普复杂的酸二聚体动力学的一个明显的策略是研究醇与酸分子的混合配对。令人惊讶的是，这样的中性分子对仍然在很大程度上未被表征，并且最近发表的微波研究推测性地将非共价对的自发定量化学反应归咎于酯的洗脱性。在初步的工作中，我们能够部分地修改这种解释，现在要仔细和全面的特点，这种新的，混合分子对的拉曼和红外光谱在超音速射流膨胀。这将涉及化学和同位素替代实验。铰链状的醇-酸复合物允许醇和羧基上的取代基之间通过微妙的分子间力（包括手性识别）在长距离处进行灵活的相互作用。最后，一个新的模型系统的相互作用的强氢键与弱相互作用之间的酒精和酸性残基应启用的量子化学和核动力学方法的实验基准。

Organic alcohols and acids are very well characterized, in particular with respect to their pairing tendency. The former undergo medium strength, well characterized hydrogen bonding, whereas the hydrogen bonds between carboxylic acids are significantly stronger and the vibrational dynamics of the acidic protons becomes irregular. An obvious strategy to cope with the complex acid dimer dynamics is to study the mixed pairing of an alcohol with an acid molecule. Surprisingly, such neutral molecular pairs have remained largely uncharacterized and a recently published microwave study speculatively blames spontaneous, quantitative chemical reaction of the non-covalent pairs to esters for their elusiveness. In preliminary work, we were able to partially revise this interpretation and now want to carfully and comprehensively characterize such novel, mixed molecular pairs by Raman and infrared spectroscopy in supersonic jet expansions. This will involve chemical and isotopic substitution experiments. The hinge-like alcohol-acid complexes allow for flexible interactions at long distance between the substituents on the alcohol and carboxyl groups via subtle intermolecular forces, including chirality recognition. In the end, a new model system for the interplay of strong hydrogen bonds with weak interactions between alcoholic and acidic residues shall be enabled for the experimental benchmarking of quantum chemical and nuclear dynamical methods.