| Summary: | 碩士 === 輔仁大學 === 化學系 === 97 === A series of multi-ruthenium complexes with CN - bridge ligand were synthesized. To figure out the electron-transfer process, the RuⅢ/Ⅱ potentials and the redox titration absorption spectra were examined. According to the electrochemistry, we calculated the comproportionation constant (KC) to realize the stability of mixed-valence complexes including [(bpy)2Ru{-CNRu(tpy)(bpy)}2]4+/5+/6+, [(bpy)2Ru{-NC-Ru(tpy)(bpy)}2]5+/6+/7+, [(bpy)2Rh{-CN-Ru(tpy)(bpy)}2]5+/6+/7+, [{(bpy)2Rh}2{-(CN)2 Ru(bpy)}2]6+/7+/8+, [{(bpy)2Ru}2{-(CN)2 Ru(bpy)}2]4+/5+/6+, and [{(bpy)2Ru}2{-(CN)2 Ru(bpy)}2]6+/7+/8+; moreover, the KC of complexes are 185, 200, 4 ~ 15, 20, 4690, and 21500, respectively, where tpy = 2, 2′: 6′, 2ʺ-terpyridine，bpy = 2, 2′-bipyridine. We built multi-state models with these mixed-valence complexes by combining the RuⅢ/Ⅱ potentials with the max of intervalence charge transfer band (IVCT band) that we measured, which are [(bpy)(tpy)Ru-CN-Ru(tpy)(bpy)]3+ , max = 7350 cm-1; [(bpy)2Ru{-CN-Ru(tpy)(bpy)}2] 5+ , max = 7630 and 10600 cm-1; [(bpy)2Ru{-NC-Ru(tpy)(bpy)}2] 6+ , max = 8900 cm-1; [{(bpy)2Ru}2{-(CN)2 Ru(bpy)}2]5+ max = 7350 and 11600 cm-1; [{(bpy)2Ru}2{-(CN)2 Ru(bpy)}2]6+ max = 9950 cm-1. We took advantages of perturbation argument and Gr, which is the resonance free energy of comproportionation energy (GC) to compute the HDA(eff), the effective coupling between Donor/Acceptor; also, we calculated the coupling between Donor/Acceptor (HDA) by Mulliken-Hush expression. Depending on these calculations, we further our knowledge about the contributions of superexchange for end-to-end interaction that is reasoning from two-state model to three-state model.
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