美国密歇根州立大学McCusker, James K.团队建立了钴(III)多吡啶配合物激发态动力学中马库斯反转区行为的起源。相关研究成果发表在2024年7月4日出版的国际学术期刊《自然—化学》。

人们对第一排过渡金属配合物在许多应用环境中的使用越来越感兴趣，包括但不限于光氧化还原催化和太阳能转换，这突出了详细了解其光物理性质的必要性。最近对使用钴（III）多吡啶的配体场光催化的关注，特别是释放了前所未有的激发态反应。

对Co（III）发色团的光物理研究通常相对不常见，因此研究人员对一系列Co（Ⅲ）多吡啶配合物进行了系统的研究，以描述它们的激发态动力学。制备了具有不同配体场强度的化合物，并使用可变温度超快瞬态吸收光谱对其进行了研究。

数据分析表明，基态恢复动力学在Marcus反转区运行，与在其他第一排金属络合物中通常观察到的情况形成鲜明对比。该分析进一步揭示了驱动这种激发态行为的根本原因，从而使马库斯反转区域在各种光解应用中的靶向使用方面取得了潜在进展。

附：英文原文

Title: Establishing the origin of Marcus-inverted-region behaviour in the excited-state dynamics of cobalt(III) polypyridyl complexes

Author: Ghosh, Atanu, Yarranton, Jonathan T., McCusker, James K.

Issue&Volume: 2024-07-04

Abstract: Growing interest in the use of first-row transition metal complexes in a number of applied contexts—including but not limited to photoredox catalysis and solar energy conversion—underscores the need for a detailed understanding of their photophysical properties. A recent focus on ligand-field photocatalysis using cobalt(III) polypyridyls in particular has unlocked unprecedented excited-state reactivities. Photophysical studies on Co(III) chromophores in general are relatively uncommon, and so here we carry out a systematic study of a series of Co(III) polypyridyl complexes in order to delineate their excited-state dynamics. Compounds with varying ligand-field strengths were prepared and studied using variable-temperature ultrafast transient absorption spectroscopy. Analysis of the data establishes that the ground-state recovery dynamics are operating in the Marcus inverted region, in stark contrast to what is typically observed in other first-row metal complexes. The analysis has further revealed the underlying reasons driving this excited-state behaviour, thereby enabling potential advancements in the targeted use of the Marcus inverted region for a variety of photolytic applications.

DOI: 10.1038/s41557-024-01564-3

Source: https://www.nature.com/articles/s41557-024-01564-3