A Highly Symmetric Metal–Organic Framework Based on a Propeller-Like Ru-Organic Metalloligand for Photocatalysis and Explosives Detection

Ru­(H2dcbpy)32+, one of the Ru­(bpy)32+ (dcbpy
= 2,2′-bipyridine-4,4′-dicarboxylic
acid, bpy = 2,2′-bipyridine) derivatves, has been used as a
propeller-like photoactive metalloligand to coordinate with indium­(III)
ions to form a highly symmetric metal–organic framework [InRu­(dcbpy)3]­[(CH3)2NH2]·6H2O (1), and the cubic microcrystals of 1 have been acquired through modified procedures. Compound 1 manifests broad visible light absorption band and strong red light
emission with long decay lifetime, both of which are originated from
the metal-to-ligand charge transfer of the Ru­(dcbpy)34– metalloligands. Because of the highly light-harvesting
and strong redox nature of the Ru­(dcbpy)32+ units
in 1, its photocatalysis activities were determined by
visible light-induced photodegradation of methyl orange experiments.
The results indicate that 1 can be a stable and good
visible-light driving heterogeneous photocatalyst. Meanwhile, the
sensing properties of 1 were also evaluated, and the
result shows that 1 can selectively detect the nitro
explosives molecules.

二(氢代联吡啶二羧酸)合钌(II)阳离子（Ru(H₂dcbpy)₃²⁺）作为三联吡啶合钌(II)阳离子（Ru(bpy)₃²⁺，其中dcbpy为2,2'-联吡啶-4,4'-二羧酸，bpy为2,2'-联吡啶）的衍生物之一，被用作螺旋桨状光活性金属配体（metalloligand），与铟(III)离子配位构筑得到高对称性金属-有机骨架（metal-organic framework）[InRu(dcbpy)₃][(CH₃)₂NH₂]·6H₂O（记为化合物1），并通过改良合成方法获得了该化合物的立方微晶。化合物1展现出宽谱可见吸收带与强红色发光特性，且具备较长的荧光衰减寿命，上述光学性能均来源于Ru(dcbpy)₃⁴⁻金属配体的金属到配体电荷转移（metal-to-ligand charge transfer）过程。由于化合物1中Ru(dcbpy)₃²⁺单元具备优异的光捕获能力与较强的氧化还原特性，我们通过可见光诱导甲基橙光降解实验评估了其光催化活性。实验结果表明，化合物1是一种稳定且性能优异的可见光驱动非均相光催化剂。与此同时，我们还测试了化合物1的传感性能，结果显示其可选择性识别硝基爆炸物分子。