Spectroscopic Probes of Molecular Structure and Dynamics

耶鲁大学的帕特里克·h·瓦卡罗（Patrick H. Vaccaro）得到化学学部化学结构、动力学和机制项目的支持，研究与物理性质和化学倾向有关的分子行为的基本方面。新形式的线性和非线性激光光谱学被用于询问气相物种，展示渗透分子科学的关键现象，包括氢键，质子转移和光学活性。基于非线性光谱学的独特能力，Vaccaro教授和他的研究小组探索了tropolone和相关物质中振动介导的质子转移，并将此类研究扩展到弱结合加合物，从而可以检查多个质子转移反应的合作方面。基于腔衰荡偏振的超灵敏光学技术被用于研究稀薄介质中天然光学活性的色散（圆双折射）和吸收（圆二色性）成分，从而阐明溶剂化、构象和振动对固有光学响应的作用。后一项工作提供了许多重要的和非直觉的见解，同时也有助于评估手性分子光学性质的计算预测。氢键和质子转移在自然界中无处不在，负责调节从液态水到体内生物分子的各种系统的结构和动力学。除了影响广泛的化学研究领域外，参与的学生还将在多学科环境中接受培训，该环境强调当代分子光谱方法和光学/激光技术的相关方面，从而为他们进入现代技术劳动力做好准备。由于他的研究小组在历史上主要是女性，瓦卡罗教授也在为增加从这个特殊的代表性不足的群体中抽取的职业科学家的数量做出贡献。

Patrick H. Vaccaro of Yale University is supported by the Chemical Structure, Dynamics, and Mechanisms Program of the Chemistry division to investigate fundamental aspects of molecular behavior responsible for physical properties and chemical propensities. Novel forms of linear and nonlinear laser spectroscopy are enlisted to interrogate gas-phase species exhibiting key phenomena that permeate molecular science, including hydrogen bonding, proton transfer, and optical activity. Building on the unique capabilities of nonlinear optical spectroscopy, Prof. Vaccaro and his research group explore vibrationally mediated proton transfer in tropolone and related species, with extensions of such studies to weakly bind adducts allowing cooperative aspects of multiple proton-transfer reactions to be examined. Ultrasensitive chiroptical techniques based upon cavity ring-down polarimitry are used to interrogate the dispersive (circular birefringence) and absorptive (circular dichroism) components of natural optical activity in rarefied media, thereby elucidating the role of solvation, conformation, and vibration on intrinsic chiroptical response. The latter work has provided a number of important and non-intuitive insights, while also serving to assess computational predictions for the optical properties of chiral molecules.Hydrogen bonding and proton transfer are ubiquitous in nature, responsible for mediating the structure and dynamics of diverse systems ranging from liquid water to in vivo biomolecules. Besides impacting broad realms of chemical research, participating students are trained in a multidisciplinary environment that emphasizes contemporary methods of molecular spectroscopy and related aspects of optical/laser technology, thereby preparing them to enter the modern technical workforce. Since his research group historically has been primarily female in character, Prof. Vaccaro also is contributing to increasing the number of career scientist drawn from this particular underrepresented group.