Das Ankita, Ghosh Prabir, Plebst Sebastian, Schwederski Brigitte, Mobin Shaikh M, Kaim Wolfgang, Lahiri Goutam Kumar
†Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
‡Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany.
Inorg Chem. 2015 Apr 6;54(7):3376-86. doi: 10.1021/ic503070j. Epub 2015 Mar 19.
The compounds Ru(acac)2(Q) (1), Ru(bpy)2(Q)2 (22), and [Ru(pap)2(Q)]PF6 ([3]PF6), containing Q = N,N'-diphenyl-o-benzoquinonediimine and donating 2,4-pentanedionate ligands (acac(-)), π-accepting 2,2(/)-bipyridine (bpy), or strongly π-accepting 2-phenylazopyridine (pap) were prepared and structurally identified. The electronic structures of the complexes and several accessible oxidized and reduced forms were studied experimentally (electrochemistry, magnetic resonance, ultraviolet-visible-near-infrared (UV-vis-NIR) spectroelectrochemistry) and computationally (DFT/TD-DFT) to reveal significantly variable electron transfer behavior and charge distribution. While the redox system 1(+)-1(-) prefers trivalent ruthenium with corresponding oxidation states Q(0)-Q(2-) of the noninnocent ligand, the series 2(2+)-2(0) and 3(2+)-3(-) retain Ru(II). The bpy and pap co-ligands are not only spectators but can also be reduced prior to a second reduction of Q. The present study with new experimental and computational evidence on the influence of co-ligands on the metal is complementary to a report on the substituent effects in o-quinonediimine ligands [Kalinina et al., Inorg. Chem. 2008, 47, 10110] and to the discussion of the most appropriate oxidation state formulation Ru(II)(Q(0)) or Ru(III)(Q(• -)).
制备并通过结构鉴定了含有Q = N,N'-二苯基邻苯醌二亚胺以及供电子的2,4-戊二酮配体（acac(-)）、π-接受型的2,2'-联吡啶（bpy）或强π-接受型的2-苯基偶氮吡啶（pap）的化合物Ru(acac)2(Q)（1）、Ru(bpy)2(Q)2（22）和[Ru(pap)2(Q)]PF6（[3]PF6）。通过实验（电化学、磁共振、紫外-可见-近红外（UV-vis-NIR）光谱电化学）和计算（DFT/TD-DFT）研究了这些配合物及其几种可及的氧化态和还原态的电子结构，以揭示显著变化的电子转移行为和电荷分布。虽然氧化还原体系1(+)-1(-)倾向于三价钌以及非无辜配体相应的氧化态Q(0)-Q(2-)，但系列2(2+)-2(0)和3(2+)-3(-)保留Ru(II)。bpy和pap共配体不仅是旁观者，而且在Q的第二次还原之前也可以被还原。本研究关于共配体对金属影响的新实验和计算证据，补充了一篇关于邻苯醌二亚胺配体中取代基效应的报告[Kalinina等人，《无机化学》，2008年，47卷，10110页]，以及关于最合适的氧化态表述Ru(II)(Q(0))或Ru(III)(Q(• -))的讨论。
