Architecture of supramolecular metal complexes for photocatalytic CO2 reduction:: Ruthenium-rhenium bi- and tetranuclear complexes
Architecture of supramolecular metal complexes for photocatalytic CO2 reduction:: Ruthenium-rhenium bi- and tetranuclear complexes
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DOI：
10.1021/ic048779r
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发表时间：
2005-04-04
影响因子：
4.6
通讯作者：
Ishitani, O
中科院分区：
文献类型：
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作者：
Gholamkhass, B;Mametsuka, H;Ishitani, O
我们研究了一系列由桥联配体1，3-bis连接的Ru（II）-Re（I）双核配合物的电化学、光谱和光催化性质（4 ′-甲基-[2，2 ′]联吡啶基-4-基）丙-2-醇（bpyC（3）bpy）和4-甲基-4 ′-[1，10]菲咯啉-[5，6-d]咪唑-2-基）联吡啶（mnipy）和其中三个[Re（CO）（3）Cl]部分使用bpyC（3）bpy配体与中心Ru配位的四核配合物。在bpyC（3）bpy双核配合物中，4，4 '-二甲基-2，2'-联吡啶（dmb）和4，4 '-双（三氟甲基）-2，2'-联吡啶（{CF 3}（2）bpy）以及2，2 '-联吡啶（bpy）被用作Ru部分的外围配体。结果表明，只有[Ru{bpyC（3）bpyRe（CO）（3）Cl}（3）]（2+）（RuRe 3）和双核配合物[（dmb）（2）Ru（bpyC（3）bpy）Re-（CO）（3）Cl]（2+）（d（2）Ru-Re）的光催化活性才有较大的提高，而且光催化反应范围进一步扩展到可见光区. 1-苄基-1，4-二氢烟酰胺（BNAH）能有效地猝灭钌的激发态。在d（2）Ru-Re的情况下，在还原淬灭之后，通过瞬态吸收光谱证实了单电子还原（OER）物种的产生，对于所述单电子还原物种，添加的电子驻留在桥连配体bpyC（3）bpy的Ru结合的bpy末端上。通过相对缓慢的分子内电子转移，从减少Ru结合bpy的Re网站，发生在交换率（Δ G类似于0）产生的减少Re部分。电子转移不需要很快，因为速率决定过程是用Re位点的OER物质还原CO2，将这些结果与其他双金属系统的结果进行比较，为我们构建用于CO2还原的超分子光催化剂提供了更一般的体系结构指针。
We study the electrochemical, spectroscopic, and photocatalytic properties of a series of Ru(II)-Re(I) binuclear complexes linked by bridging ligands 1,3-bis(4 '-methyl-[2,2 ']bipyridinyl-4-yl)propan-2-ol (bpyC(3)bpy) and 4-methyl-4 '-[1,10]phenanthroline-[5,6-d]imidazol-2-yl)bipyridine (mfibpy) and a tetranuclear complex in which three [Re(CO)(3)Cl] moieties are coordinated to the central Ru using the bpyC(3)bpy ligands. In the bpyC(3)bpy binuclear complexes, 4,4 '-dimethyl-2,2 '-bipyridine (dmb) and 4,4 '-bis(trifluoromethyl)-2,2 '-bipyridine ({CF3}(2)bpy), as well as 2,2 '-bipyridine (bpy), were used as peripheral ligands on the Ru moiety. Greatly improved photocatalytic activities were obtained only in the cases of [Ru{bpyC(3)bpyRe(CO)(3)Cl}(3)](2+) (RuRe3) and the binuclear complex [(dmb)(2)Ru(bpyC(3)bpy)Re-(CO)(3)Cl](2+) (d(2)Ru-Re), while photocatalytic responses were extended further into the visible region. The excited state of ruthenium in all Ru-Re complexes was efficiently quenched by 1-benzyl-1,4-dihydronicotinamide (BNAH). Following reductive quenching in the case of d(2)Ru-Re, generation of the one-electron-reduced (OER) species, for which the added electron resides on the Ru-bound bpy end of the bridging ligand bpyC(3)bpy, was confirmed by transient absorption spectroscopy. The reduced Re moiety was produced via a relatively slow intramolecular electron transfer, from the reduced Ru-bound bpy to the Re site, occurring at an exchange rate (Delta G similar to 0). Electron transfer need not be rapid, since the rate-determining process is reduction Of CO2 with the OER species of the Re site, Comparison of these results with those for other bimetallic systems gives us more general architectural pointers for constructing supramolecular photocatalysts for CO2 reduction.