The redox-active ligand 5,7,12,14-tetraazapentacene-6,13-quinone = L forms structurally characterised compounds with three (1) or four (2) [Ru(acac)₂] complex fragments in which each of the metals is N,O-chelated. The new tris- and tetrakis-bidentate chelate compounds exhibit ruthenium centres bridged at about 4 Å by quinone O atoms which are then situated across the pentacene π system at about 6–8 Å distance. Several electron transfer processes were observed by voltammetry (CV, DPV) and the intermediates identified by EPR and UV-Vis-NIR spectroelectrochemistry. TD-DFT calculations were applied to assign the proper oxidation states within the multistep redox systems {(μ_n-L)[Ru(acac)₂]_n}^k, n = 3 or 4, revealing both metal and ligand based electron transfer.

中文翻译：

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杂醌桥接配体的三核和四核钌配合物的非纯价和混合价

氧化还原活性配体5,7,12,14-四氮杂戊并-6,13-​​醌= L形成具有三（1）或四（2）[Ru（acac）₂ ]复杂片段的结构特征化合物，其中每个金属是N，O螯合的。新的三齿和四齿螯合物显示出钌中心被醌O原子桥接成约4Å，然后以并列的方式并列并五苯π体系约6-8Å的距离。通过伏安法（CV，DPV）观察到了几种电子转移过程，通过EPR和UV-Vis-NIR光谱电化学鉴定了中间体。TD-DFT计算被施加到多步氧化还原体系{（μ内指定适当的氧化态_Ñ -L）的[Ru（ACAC）₂ ] _Ñ} ^k，n = 3或4，同时显示出基于金属和配体的电子转移。