Two new CuII 1D-coordination polymers containing 1,4-pyrazine-2,3-dicarboxylic acid, 2-aminopyridine, and 5-bromo-6-methyl-2-(4-methylpiperazine-1-yl)pyrimidine-4-amine: X-ray crystal structure, spectroscopic and magnetic studies

► Two CuII 1D-coordination polymers containing [Cu(pyzdc)2]2− chains. ► Magnetic studies show very weak antiferromagnetic interactions. ► Structures of 1 and 2 are the same with different space groups, P1¯ and P21/c, respectively.