Gao Li-Bin, Kan Jian, Fan Yang, Zhang Li-Yi, Liu Sheng-Hua, Chen Zhong-Ning
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
Inorg Chem. 2007 Jul 9;46(14):5651-64. doi: 10.1021/ic700412m. Epub 2007 May 19.
Preparation and characterization of a series of rodlike binuclear ruthenium polyynediyl complexes capped with redox-active organometallic fragments [(bph)(PPh3)2Ru]+ (bph=N-(benzoyl)-N'-(picolinylidene)-hydrazine) or [(Phtpy)(PPh3)2Ru]2+ (Phtpy=4'-phenyl-2,2':6',2' '-terpyridine) have been carried out. The length of the molecular rods is extended by successive insertion of 2,5-thiophene or 1,4-phenylene spacers in the bridging ligands. Oxidation of thiophene-containing Ru2II,II complexes induces isolation of stable Ru2II,III or Ru2III,III species. Electrochemical and UV-vis-NIR spectral studies demonstrate that the polyynediyl bridges with 2,5-thiophene units are more favorable for metal-metal charge transfer compared with those containing the same number of 1,4-phenylene units. Successive increase of thiophene spacers in mixed-valence complexes {RuII}-CC(C4H2S)mCC-{RuIII} (m=1, 2, 3) induced a smooth transition from almost electronic delocalization (m=1) to localization (m=3). For binuclear ruthenium complexes with intramolecular electron transfer transmitted across nine Ru-C and C-C bonds, electronic conveying capability follows {Ru}-CC(CC)2CC-{Ru}>{Ru}-CC(C4H2S)CC-{Ru}>{Ru}-CC(C6H4)CC-{Ru}>{Ru}-CC(CH=CH)2CC-{Ru}. It is revealed that molecular wires capped with electron-rich (bph)(PPh3)2Ru endgroups are much more favorable for electronic communication than the corresponding electron-deficient (Phtpy)(PPh3)2Ru-containing counterparts. The intermetallic electronic communication is fine-tuned by modification of both the bridging spacers and the ancillary ligands.
一系列以氧化还原活性有机金属片段[(bph)(PPh₃)₂Ru⁺]（bph = N-(苯甲酰基)-N'-(吡啶基亚甲基)-肼）或[(Phtpy)(PPh₃)₂Ru]²⁺（Phtpy = 4'-苯基-2,2':6',2''-三联吡啶）封端的棒状双核钌聚炔二基配合物的制备及表征已完成。通过在桥连配体中连续插入2,5-噻吩或1,4-亚苯基间隔基来延长分子棒的长度。含噻吩的Ru₂⁽⁺⁺,⁺⁺⁾配合物的氧化诱导稳定的Ru₂⁽⁺⁺,⁺⁺⁺⁾或Ru₂⁽⁺⁺⁺,⁺⁺⁺⁾物种的分离。电化学和紫外-可见-近红外光谱研究表明，与含有相同数量1,4-亚苯基单元的聚炔二基桥相比，含2,5-噻吩单元的聚炔二基桥更有利于金属-金属电荷转移。混合价配合物{Ru⁺⁺}-CC(C₄H₂S)ₘCC-{Ru⁺⁺⁺}（m = 1, 2, 3）中噻吩间隔基的连续增加导致从几乎电子离域（m = 1）到局域化（m = 3）的平滑转变。对于分子内电子转移通过九个Ru-C和C-C键进行传递的双核钌配合物，电子传输能力遵循{Ru}-CC(CC)₂CC-{Ru}>{Ru}-CC(C₄H₂S)CC-{Ru}>{Ru}-CC(C₆H₄)CC-{Ru}>{Ru}-CC(CH=CH)₂CC-{Ru}。结果表明，以富电子的(bph)(PPh₃)₂Ru端基封端的分子导线比相应的含电子不足的(Phtpy)(PPh₃)₂Ru的对应物更有利于电子通讯。通过修饰桥连间隔基和辅助配体来微调金属间的电子通讯。
