CAREER: CAS: Organic Photochemistry for Light-Driven CO2 Capture and Release

在化学部化学结构、动力学机制-B（CSDM-B）项目的支持下，哈佛大学化学与化学生物学系的Richard Liu正在开发新型光开关有机化合物，以控制二氧化碳（CO2）与可见光的结合和释放。这一基础知识可用于开发利用来自阳光的能量以将CO2从排放流或直接从大气中分离，然后根据需要释放捕获的CO2以供利用或储存的装置。该项目将这些研究目标与旨在促进更广泛参与科学事业的教育活动相结合，特别是针对波士顿地区的K-12学生以及成人和非传统学习者。此外，还将开发针对盲人和低视力学生的有机化学概念教学工具，重点关注与研究目标相关的分子几何学、立体化学和异构化反应等主题。光致变色有机分子是有前途的直接光驱动分离材料，因为它们可以在两种或多种化学性质差异很大的异构体之间有效地转换。拟议的研究概述了一般计划耦合这些光控制的平衡，下游光独立的平衡，涉及CO2吸收到溶液中。在一种模式中，在辐照后进入亚稳态、高酸性状态的新化合物将用于被动捕获和按需释放CO2。在第二种互补模式中，可逆的光碱--一种被忽视的化合物，已知的例子很少--将被用来实现光触发捕获和逐渐被动释放。还将探讨涉及光酸或光碱与传统胺吸附剂组合的合作机制。对于每一类化合物，将使用原位分光光度法、pH值和CO2测量以及超快光谱来表征关键的光化学机制。有效的光开关的热力学要求将通过光开关的系统综合和评估来揭示。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

With support from the Chemical Structure, Dynamics & Mechanisms-B (CSDM-B) Program of the Chemistry Division, Richard Liu of the Department of Chemistry and Chemical Biology at Harvard University is developing new classes of photoswitchable organic compounds to enable control of carbon dioxide (CO2) binding and release with visible light. This fundamental knowledge may be used to develop devices that harness energy from sunlight to separate CO2 from emission streams or directly from the atmosphere and then release that captured CO2 on demand for utilization or storage. This project integrates these research goals with educational activities intended to promote broader participation in scientific careers, specifically aimed at engaging K-12 students in the Boston area as well as adult and non-traditional learners. Tools for teaching organic chemistry concepts to blind and low-vision students will also be developed, focusing on topics such as molecular geometry, stereochemistry, and isomerization reactions related to the research aims.Photochromic organic molecules are promising materials for directly light-driven separations, as they may be efficiently switched between two or more isomeric forms that can differ significantly in their chemical properties. The proposed research outlines general schemes for coupling of these optically controlled equilibria to downstream light-independent equilibria involving CO2 uptake into solution. In one mode, new compounds that enter a metastable, highly acidic state upon irradiation will be used for passive capture and on-demand release of CO2. In a second, complementary mode, reversible photobases – a neglected class of compounds with few known examples – will be employed to enable light-triggered capture and gradual passive release. Co-operative mechanisms involving the combination of photoacids or photobases with traditional amine sorbents will also be explored. For each class of compounds, in situ spectrophotometry, pH and CO2 measurement, and ultrafast spectroscopy will be used to characterize key photochemical mechanisms. The thermodynamic requirements for effective photoswitching will be revealed through systematic synthesis and evaluation of photoswitches.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.