{"title":"Steric and Electronic Influence of Excited-State Decay in Cu(I) MLCT Chromophores","authors":"Felix N. Castellano, Michael C. Rosko","doi":"10.1021/acs.accounts.4c00476","DOIUrl":null,"url":null,"abstract":"For the past 11 years, a dedicated effort in our research group focused on fundamentally advancing the photophysical properties of cuprous <i>bis</i>-phenanthroline-based metal-to-ligand charge transfer (MLCT) excited states. We rationalized that, by gaining control over the numerous factors limiting the more widespread use of Cu<sup>I</sup> MLCT photosensitizers, they would be readily adopted in numerous light-activated applications given the earth-abundance of copper and the extensive library of 1,10-phenanthrolines developed over the last century. Significant progress has been achieved by recognizing valuable structure–property concepts developed by other researchers in tandem with detailed ultrafast and conventional time-scale investigations, <i>in-silico</i>-inspired molecular designs to predict spectroscopic properties, and applying novel synthetic methodologies. Ultimately, we achieved a plateau in exerting cooperative steric influence to control Cu<sup>I</sup> MLCT excited state decay. This led to combining sterics with π-conjugation and/or inductive electronic effects to further exert control over molecular photophysical properties. The lessons gleaned from our studies of homoleptic complexes were recently extended to heteroleptic <i>bis</i>(phenanthrolines) featuring enhanced visible light absorption properties and long-lived room-temperature photoluminescence. This <i>Account</i> navigates the reader through our intellectual journey of decision-making, molecular and experimental design, and data interpretation in parallel with appropriate background information related to the quantitative characterization of molecular photophysics using Cu<sup>I</sup> MLCT chromophores as prototypical examples.","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4000,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Accounts of Chemical Research","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1021/acs.accounts.4c00476","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
For the past 11 years, a dedicated effort in our research group focused on fundamentally advancing the photophysical properties of cuprous bis-phenanthroline-based metal-to-ligand charge transfer (MLCT) excited states. We rationalized that, by gaining control over the numerous factors limiting the more widespread use of CuI MLCT photosensitizers, they would be readily adopted in numerous light-activated applications given the earth-abundance of copper and the extensive library of 1,10-phenanthrolines developed over the last century. Significant progress has been achieved by recognizing valuable structure–property concepts developed by other researchers in tandem with detailed ultrafast and conventional time-scale investigations, in-silico-inspired molecular designs to predict spectroscopic properties, and applying novel synthetic methodologies. Ultimately, we achieved a plateau in exerting cooperative steric influence to control CuI MLCT excited state decay. This led to combining sterics with π-conjugation and/or inductive electronic effects to further exert control over molecular photophysical properties. The lessons gleaned from our studies of homoleptic complexes were recently extended to heteroleptic bis(phenanthrolines) featuring enhanced visible light absorption properties and long-lived room-temperature photoluminescence. This Account navigates the reader through our intellectual journey of decision-making, molecular and experimental design, and data interpretation in parallel with appropriate background information related to the quantitative characterization of molecular photophysics using CuI MLCT chromophores as prototypical examples.
在过去的 11 年中,我们的研究小组一直致力于从根本上提高基于铜双菲罗啉的金属-配体电荷转移(MLCT)激发态的光物理特性。我们认为,通过控制限制 CuI MLCT 光敏剂更广泛应用的众多因素,考虑到地球上铜的丰富性和上个世纪开发的大量 1,10-菲罗啉,这些光敏剂将很容易应用于众多光激活应用中。通过认识其他研究人员提出的有价值的结构-性能概念,结合详细的超快和常规时间尺度研究、硅内分子设计以预测光谱特性,以及应用新型合成方法,我们取得了重大进展。最终,我们在施加合作立体影响以控制 CuI MLCT 激发态衰变方面取得了突破。这促使我们将立体效应与π共轭和/或感应电子效应相结合,进一步控制分子的光物理特性。我们从同色复合物的研究中总结出的经验最近扩展到了异色双菲罗啉,其特点是具有增强的可见光吸收特性和长寿命室温光致发光。本报告以 CuI MLCT 发色团为原型,通过与分子光物理定量表征相关的适当背景信息,引导读者了解我们在决策、分子和实验设计以及数据解释方面的知识历程。
期刊介绍:
Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance.
Accounts of Chemical Research replaces the traditional article abstract with an article "Conspectus." These entries synopsize the research affording the reader a closer look at the content and significance of an article. Through this provision of a more detailed description of the article contents, the Conspectus enhances the article's discoverability by search engines and the exposure for the research.