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

Abstract

In this work, we report the design and synthesis of two 1D-coordination polymers under ambient condition namely {[H2-apy]2[Cu(pyzdc)2]}n (1) and {[Hbmpa]2[Cu(pyzdc)2]·2H2O}n (2), which have been prepared by the reaction between CuCl2·2H2O, 1,4-pyrazine-2,3-dicarboxylic acid (H2pyzdc) and 2-aminopyridine (2-apy) or 5-bromo-6-methyl-2-(4-methylpiperazine-1-yl)pyrimidine-4-amine (bmpa). The compounds have been structurally determined by single crystal X-ray diffraction analyses, elemental analyses and IR spectra. These coordination polymers consist of [Cu(pyzdc)2]2− chains and discrete positively charged 2-apy or bmpa fragments. In 1 and 2, the variable temperature magnetic measurements show very weak antiferromagnetic interactions between the CuII centers.