Solvent-regulated assemblies of silver(I) and cadmium(II) supramolecular complexes with versatile tripyridyltriazole multidentate ligands

This work presents two pairs of Ag(I) and Cd(II) supramolecular complexes assembled based on two versatile tripyridyltriazole ligands 3,5-bis(2-pyridyl)-4-(4-pyridyl)-1,2,4-triazole (L242) and 3-(2-pyridyl)-4,5-bis(4-pyridyl)-1,2,4-triazole (L244), respectively. All four complexes have been prepared under similar conditions and characterized by elemental analysis, IR, and powder X-ray diffraction techniques. Single-crystal X-ray diffraction indicates that these complexes display the infinite 1-D and 2-D arrays for {[Ag(L242)(CF3COO)](CH3OH)}n (1) and {[Ag2(L242)(CF3COO)2](CH3CN)0.75(H2O)0.25}n (2) as well as discrete dinuclear and tetranuclear coordination patterns for [Cd(L244)I2]2 (3) and [Cd2(L244)2I4(DMF)2]2(DMF)2 (4). In 1 and 3, extended supramolecular architectures are further constructed via aromatic stacking interactions. Structural difference for each pair of complexes can be properly assigned to the significant solvent effect on assembled reactions (CH3OH–H2O vs. CHCl3–CH3CN for 1 and 2 as well as CH3OH–H2O vs. H2O–DMF for 3 and 4). Thermal stability and fluorescence of these complexes have also been investigated.