Exploiting the disulfide/dithiol switch in photoinduced proton coupled electron transfer reactions

在光诱导质子耦合电子转移反应中利用二硫化物/二硫醇开关

• 批准号: 404391096
• 负责人: Professor Dr. Franc Meyer
• 金额: --
• 依托单位: Institut für Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/404391096?language=en
• 关键词: Exploiting; disulfide; dithiol; switch; photoinduced

The transformation of small molecules relevant for sustainable energy scenarios, specifically the generation of solar fuels, usually requires the transfer of multiple electrons and protons. Catalysts mediating these challenging transformations of mostly inert molecules thus have to orchestrate the complex multielectron, multiproton transfer to/from the substrate, viz. the proton-coupled electron transfer (PCET) events that are also widespread in biological systems. These processes may proceed sequentially via proton transfer followed by electron transfer (PT-ET), or vice versa (ET-PT), or the electron and proton may be transferred in a concerted fashion (CPET) to avoid any charged intermediates of potentially high energy. Because of their inherent nonequilibrium nature when occurring from photoexcited states, PCET scenarios driven by light are particularly complex and not well understood. However, understanding and controlling the dynamics of multiple light-triggered charge transfer processes will ultimately be crucial for improved sunlight to fuel conversion and for any desired energy storage in solar fuels. This fundamental research project targets the elucidation of the sequence of events during photoinduced PCET processes using novel photoexcitable metal complexes that are decorated with a disulfide/dithiol switch in the ligand periphery. The proposed chemistry capitalizes on the 2e−/2H+ nature of the disulfide/dithiol interconversion and on the potential inversion that often occurs after the first reduction of a disulfide moiety. Building upon the progress achieved during the first funding period, key questions of this project concern the choreography of the individual chemical steps following photoexcitation of well-designed molecular and supramolecular systems, including ET, PT and the rupture of the S-S bond. These questions are addressed by an interdisciplinary project team and in close collaborations with several research groups of the priority program, using a suite of experimental and computational methods. The conceptual guideline, and the ultimate goal, is the triggering of a second ET event, potentially coupled to PT, following the initial excited state PCET process. This will open a promising entry towards multielectron/multiproton chemistry initiated by single photoexcitation event.

与可持续能源场景相关的小分子转化，特别是太阳能燃料的产生，通常需要多个电子和质子的转移。因此，介导大多数惰性分子的这些具有挑战性的转化的催化剂必须协调复杂的多电子、多质子转移至/来自基质，即。质子耦合电子转移（PCET）事件在生物系统中也广泛存在。这些过程可以通过质子转移然后电子转移（PT-ET）顺序进行，反之亦然（ET-PT），或者电子和质子可以以协调的方式转移（CPET）以避免任何潜在高能的带电中间体。由于光激发态时其固有的非平衡性质，由光驱动的 PCET 场景特别复杂且不易被理解。然而，理解和控制多个光触发电荷转移过程的动态最终对于改善阳光到燃料的转化以及太阳能燃料中任何所需的能量存储至关重要。该基础研究项目的目标是使用配体外围装饰有二硫化物/二硫醇开关的新型光可激发金属配合物来阐明光诱导 PCET 过程中的事件顺序。所提出的化学方法利用了二硫键/二硫醇互变的 2e−/2H+ 性质以及二硫键部分第一次还原后经常发生的潜在反转。在第一个资助期间取得的进展的基础上，该项目的关键问题涉及精心设计的分子和超分子系统光激发后各个化学步骤的编排，包括 ET、PT 和 S-S 键的断裂。这些问题由一个跨学科项目团队通过与优先计划的几个研究小组密切合作，使用一套实验和计算方法来解决。概念指南和最终目标是在初始激发态 PCET 过程之后触发第二个 ET 事件，可能与 PT 耦合。这将为由单次光激发事件引发的多电子/多质子化学开辟一个有希望的入口。