Synthesis,crystal structure,and blue photoluminescence of a 3D coordination polymer based on a Ag10 cluster with the versatile 2-mercapto-5-benzimidazolesulfonic acid ligand

The solvothermal reaction of 2-mercapto-5-benzimidazolesulfonic acid (H₃MBZD), which has imidazole, –SH, and –SO₃H groups, with Ag₂SO₄ led to the 3D coordination polymer {Ag₅[(HMBZD)₂(H₂MBZD)(H₂O)]} _n (1). X-ray single-crystal analysis showed that five independent Ag atoms are connected by the bridging mercapto group to generate asymmetric pentanuclear clusters, which are joined together to form a large Ag₁₀ ringed subunit. The Ag₁₀ subunits are linked together by the –SO₃H groups to give the complex 3D framework. Strong blue photoluminescence of 1 can be assigned to the intraligand fluorescent emission.