CAREER: State-Specific Characterization of Intermolecular Vibronic Mixing Between Dipyrrolic Pigment Subunits

在化学部化学结构，动力学和机制-A（CSDM-A）计划的支持下，南犹他州大学的Jacob Dean将研究特定的分子振动，从可见光和紫外光吸收中刺激，如何影响分子之间的电子能量转移，例如生物和工程系统中的光捕获相关分子。目前，了解这些系统的光吸收组件中的关键振动如何穿梭能量受到系统复杂性和能量耗散的快速时间尺度的限制。迪恩博士和他的团队将使用先进的激光和时间分辨光谱来测量分子中的这些振动运动。本科生，包括那些传统上代表性不足的群体，将在这项研究和先进的物理化学研究efforts. Laser spectroscopy耦合射流冷却将被用来使模式和量子态分辨的审问分子间的振动耦合和振动介导的能量转移的diprororoylic亚基来自天然光合色素和小diproylic聚集体在气相中。飞秒相干光谱的二吡咯聚集体在溶液中，在室温下，随后将被用来评估所产生的振动混合模型的鲁棒性。更好地理解分子之间的电子振动（电子振动）耦合有可能揭示能量如何在分子聚集体中转移。通过改进的结构-振动-功能阐明，Dean博士和他的团队旨在将这些知识扩展到生物和工程光捕获分子和材料的能量传输。在这样做的过程中，实验衔接丰富的参数空间，涉及到快速和定向的理解能量转移，纠缠量子化振动与颜料电子状态，以优化聚合物的能量景观的设想。这一奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) Program in the Division of Chemistry, Jacob Dean of Southern Utah University will investigate how specific molecular vibrations, stimulated from visible and UV light absorption, influence the transfer of electronic energy between molecules such as those relevant in light harvesting in biological and engineered systems. Currently, understanding how key vibrations in the light absorbing components of these systems shuttle energy is limited by the complexity of systems and fast time scales at which energy dissipates. Dr. Dean and his group will use advanced laser and time-resolved spectroscopies to measure these vibrational motions in molecules. Undergraduate students, including those from traditionally underrepresented groups, will be trained in this research and in advanced physical chemistry research efforts.Laser spectroscopy coupled with jet cooling will be used to enable mode- and quantum state-resolved interrogation of intermolecular vibronic coupling and vibrationally-mediated energy transfer in dipyrrolic subunits derived from native photosynthetic pigments and small dipyrrole aggregates in the gas phase. Femtosecond coherence spectroscopy of dipyrrole aggregates in solution at room temperature will subsequently be used to assess the robustness of the resulting vibronic mixing models developed. Better understanding of electronic-vibrational (vibronic) coupling between molecules has the potential to reveal how energy is transferred within molecular aggregates. Through improved structure-vibration-function elucidation, Dr. Dean and his group aim to extend this knowledge to energy transport in biological and engineered light-harvesting molecules and materials. In so doing, the experimental articulation of a rich parameter space involving both the rapid and directional understanding of energy transfer that entangles quantized vibrations with pigment electronic states to optimize the aggregate’s energy landscape is envisioned.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.