Synthesis, crystal structures and photoluminescences of silver(I) complexes with chelating carboxylic and pyrazine derivatives

Four mixed-ligand silver(I) coordination polymers (CPs) {Ag2(tpyz)(L)}_n (1), {Ag4(tpyz)2(L)2}_n (2), {Ag2(mpyz)(L)}_n (3) as well as its isomer (4), (tpyz-2,3,5-trimethylpyrazine, mpyz = 2,3,5,6-tetramethylpyrazine, H2L = (+)-camphoric acid), were synthesized with reactions of L and pyrazine derivatives with silver nitrate in different solvent systems. Systematic characterizations with single-crystal X-ray diffraction indicate that, 1 and 3 show a 3D framework which constructed by silver(I) and L anion, the pyrazine derivatives only give one N to connect to metal, which may be due to the disorder of the methyl which shares the same carbon with carboxylate; 2 and 4 demonstrate a 2D 4 4–sql network. The difference between two: one structure is single layer and the other is double layer. Furthermore, 4 contains a 1D helical chains which connected by Ag(I) and mpyz ligand. Meanwhile, the L anion exhibits different coordination modes in 1–4. 1–4 spanning from two-dimensional network to three-dimensional framework suggest that the kinds of pyrazine derivatives and solvents play significant roles in the formation of such coordination architectures. The thermogravimetric analyses (TGA), IR, and photoluminescence were also measured.