Two new cadmium(II) coordination polymers based on bis(1,2,4-triazol-1-yl)alkane ligands and pyrazine-2,3-dicarboxylic acid

Assemblies of pyrazine-2,3-dicarboxylic acid and Cd in the presence of bis(1,2,4-triazol-1-yl)butane or bis(1,2,4-triazol-1-yl)ethane under ambient conditions yielded two new coordination polymers, namely poly[[tetraaqua[μ-1,4-bis(1,2,4-triazol-1-yl)butane-κ N:N]bis(μ2-pyrazine-2,3-dicarboxylato-κ N,O:O)dicadmium(II)] dihydrate], {[Cd(CHNO)(CHN)(HO)]·2HO} n , (I), and poly[[diaqua[μ2-1,2-bis(1,2,4-triazol-1-yl)ethane-κ N:N]bis(μ3-pyrazine-2,3-dicarboxylato-κ N,O:O:O)dicadmium(II)] dihydrate], {[Cd(CHNO)(CHN)(HO)]·2HO} n , (II). Complex (I) displays an interesting two-dimensional wave-like structure and forms a distinct extended three-dimensional supramolecular structure with the help of O-H⋯N and O-H⋯O hydrogen bonds. Complex (II) has a three-dimensional framework structure in which hydrogen bonds of the O-H⋯N and O-H⋯O types are found.