Coexistence of two thermally induced intramolecular electron transfer processes in a series of metal complexes [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)2] (M = Co, Fe, and Ni) bearing non-innocent catechol-based ligands: a combined experimental and theoretical study.
Coexistence of two thermally induced intramolecular electron transfer processes in a series of metal complexes [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)2] (M = Co, Fe, and Ni) bearing non-innocent catechol-based ligands: a combined experimental and theoretical study.
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一系列金属配合物中两种热诱导分子内电子转移过程的共存 [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)2] (M = Co, Fe
作者：
E. Evangelio;M. Bonnet;M. Cabanas;M. Nakano;J. Sutter;A. Dei;V. Robert;D. Ruíz
在一系列配合物 [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)(2)] 中可以发生不同的热诱导分子间电子转移 (IET) 过程，其中 M = Co (2)、Fe (3) 和 Ni(4)，Cat-N-BQ 和 Cat-N-SQ 表示单负 (Cat-N-BQ(-)) 或双负三齿希夫碱配体 3,5-二叔丁基-1,2-醌-1-(2-羟基-3,5-二叔丁基苯基)亚胺的 (Cat-N-SQ(2-)) 自由基形式已通过变温 UV/Vis 和 NMR 光谱进行了研究。根据金属离子的不同，可以观察到相当不同的行为。配合物 2 被发现是迄今为止报道的少数几个表现出两种热诱导电子转移过程（配体到金属（IET（LM））和配体到配体（IET（LL））共存的例子之一。仅发现复合体 3 中发生了 IET(LL)，而复合体 4 中未观察到 IET。此类实验研究已与基于波函数的 CASSCF/CASPT2 计算相结合。这种策略允许人们选择性地获取推测的轨道并访问基态和激发自旋态，以及电荷转移态，从而提供有关不同 IET 过程的附加信息。
The different thermally induced intermolecular electron transfer (IET) processes that can take place in the series of complexes [M(Cat-N-BQ)(Cat-N-SQ)]/[M(Cat-N-BQ)(2)], for which M = Co (2), Fe (3) and Ni(4), and Cat-N-BQ and Cat-N-SQ denote the mononegative (Cat-N-BQ(-)) or dinegative (Cat-N-SQ(2-)) radical forms of the tridentate Schiff-base ligand 3,5-di-tert-butyl-1,2-quinone-1-(2-hydroxy-3,5-di-tert-butylphenyl)imine, have been studied by variable-temperature UV/Vis and NMR spectroscopies. Depending on the metal ion, rather different behaviors are observed. Complex 2 has been found to be one of the few examples so far reported to exhibit the coexistence of two thermally induced electron transfer processes, ligand-to-metal (IET(LM)) and ligand-to-ligand (IET(LL)). IET(LL) was only found to take place in complex 3, and no IET was observed for complex 4. Such experimental studies have been combined with ab initio wavefunction-based CASSCF/CASPT2 calculations. Such a strategy allows one to solicit selectively the speculated orbitals and to access the ground states and excited-spin states, as well as charge-transfer states giving additional information on the different IET processes.