A novel mixed-valence copper coordination polymer: synthesis, characterization and crystal structure

Hydrothermal reaction of copper(II) nitrate trihydrate with 2-pyrazinecarboxylic acid in the presence of phosphorous acid gave a novel mixed-valence coordination polymer, [Cu(I)Cu(II)(C5H3N2O2)(2)(NO3)(H2O)](n) ( 1), which has been structurally characterized. Crystal data: triclinic, P(1) over bar, a = 6.2266(6), b = 8.0148(7), c = 14.443(1) angstrom, alpha = 74.698(1), beta = 84.865(1), gamma = 84.532(1)degrees, V = 690.51(11) angstrom(3), Z = 2, R-1 = 0.0262. The complex features linear -Cu(1)(2-pyrazinecarboxylate)-Cu(2)-(NO3)(H2O)(2- pyrazinecarboxylate)-Cu(3)(2-pyrazinecarboxylate)-Cu(2)(NO3)(H2O)(2-pyrazinecarboxylate)- strands cross-linked by water molecules to form a two-dimensional sheet, further connected by intralayer Cu(2)center dot center dot center dot NO3- interactions to form a novel cavity. Other characteristic data are given.