Metal–Metal-to-Ligand Charge Transfer in Pt(II) Dimers Bridged by Pyridyl and Quinoline Thiols
Metal–Metal-to-Ligand Charge Transfer in Pt(II) Dimers Bridged by Pyridyl and Quinoline Thiols
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由吡啶基和喹啉硫醇桥接的 Pt(II) 二聚体中的金属 - 金属到配体的电荷转移
DOI：
10.1021/acs.inorgchem.1c02469
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发表时间：
2022
影响因子：
4.6
通讯作者：
Castellano, Felix N.
中科院分区：
文献类型：
--
作者：
Roy, Subhangi;Lopez, Antonio A.;Yarnell, James E.;Castellano, Felix N.
基于抗 [Pt(C∧N)(μ-N∧S)]2 的两种不同种类的方形平面双核 Pt(II) 二聚体的研究，其中 C∧N 是 2-苯基吡啶 (ppy) 或苯并(h)喹啉 (bzq)，N∧S 是吡啶-2-硫醇 (pyt)、6-甲基吡啶-2-硫醇 (Mpyt)，或提出了 2-喹啉硫醇 (2QT)。通过电子结构计算、静态紫外-可见光和光致发光 (PL) 光谱、循环伏安法以及瞬态吸光度和时间选通 PL 实验对每个分子进行了彻底表征。这些可见吸收发色团具有金属-金属-配体电荷转移 (MMLCT) 激发态，这些激发态源自分子内 d8-d8 金属-金属 σ 相互作用，并体现在这些分子的基态和激发态特性中。报告的所有五种分子（无法分离抗[Pt(ppy)(μ-Mpyt)]2），其中三种是这里新构思的，具有超过 500 nm 的电子吸收和高量子产率 PL 发射，光谱延伸至远红光 (λem> 700 nm)，源自每种情况下的电荷转移态。每个发色团都显示出通过动态吸收和 PL 实验记录的单指数充分建模的激发态衰变动力学；每种技术都会产生相似的衰变动力学。综合数据表明，吡啶基和喹啉硫醇盐与选定的环金属盐一起代表了 MMLCT 发色团的类别，这些发色团表现出适合促进光能化学反应的激发态特性，并提供了适合评估瞬态金属-金属键形成光化学中的相干现象的分子平台。
The investigation of two distinct species of square planar dinuclear Pt(II) dimers based onanti-[Pt(C∧N)(μ-N∧S)]2, where C∧N is either 2-phenylpyridine (ppy) or benzo(h)quinoline (bzq) and N∧S is pyridine-2-thiol (pyt), 6-methylpyridine-2-thiol (Mpyt), or 2-quinolinethiol (2QT), is presented. Each molecule was thoroughly characterized with electronic structure calculations, static UV–vis and photoluminescence (PL) spectroscopy, and cyclic voltammetry, along with transient absorbance and time-gated PL experiments. These visible absorbing chromophores feature metal–metal-to-ligand charge-transfer (MMLCT) excited states that originate from intramolecular d8–d8metal–metal σ-interactions and are manifested in the ground- and excited-state properties of these molecules. All five molecules reported (anti-[Pt(ppy)(μ-Mpyt)]2could not be isolated), three of which are newly conceived here, possess electronic absorptions past 500 nm and high quantum yield PL emission with spectra extending into the far red (λem> 700 nm), originating from the charge-transfer state in each instance. Each chromophore displays excited-state decay kinetics adequately modeled by single exponentials as recorded using dynamic absorption and PL experiments; each technique yields similar decay kinetics. The combined data illustrate that pyridyl and quinoline-thiolates in conjunction with select cyclometalates represent classes of MMLCT chromophores that exhibit excited-state properties suitable for promoting light-energized chemical reactions and provide a molecular platform suitable for evaluating coherence phenomena in transient metal–metal bond-forming photochemistry.