Microwave synthesis of a blue luminescent silver(I) coordination polymer with a rigid tris-triazole ligand

Microwave-assisted hydrothermal reaction of 2-fluoro-3,5,6-tri(1H-1,2,4-triazol-1-yl)-1,4-benzenedicarbonitrile (L-1) with silver(I) nitrate yields a coordination polymer [Ag-3(L-2)(2)(NO3)](n) (1), in which the L-2 ligand (HL2 = 2-hydroxy-3,5,6-tri(1H-1,2,4-triazol-1-yl)terephthalonitrile) is obtained by in situ ligand transformation from the L-1 precursor. HL2 monohydrate has also been isolated by the microwave-mediated hydrolysis of L-1 and structurally characterized. Single-crystal X-ray diffraction reveals that HL2 monohydrate comprises a zwitterionic HL2 moiety, while complex 1 displays an infinite L-2-bridged double-chain structure. Given that the HL2 molecule has a large conjugated pi system, complex 1 exhibits strong blue luminescence in the solid state at room temperature.