Sodium ions directed self-assembly with 3,5-pyridinedicarboxylate (3,5-pdc) and 4-pyridinecarboxylate (4-pc)

A 3D sodium(I) complex driven by the coordination bonds and a 3D hydrogen-bond-sustained network, with empirical formulae [Na2(3,5-pdc)(H2O)4]n (1) and [Na2(4-pc)2(H2O)8]n (2), respectively, have been synthesized and characterized. X-ray single crystal determination of 1 reveals that two types of hexa-coordinate sodium(I) ions are alternately arranged through three double μ2-OH2 bridges and one double μ2 oxygen bridge coming from one carboxylic oxygen atom of a 3,5-pdc ligand. In comparison to 1, only one kind of six-coordinate sodium ions in octahedral coordination configurations is bridged by double μ2 aqua bridges in 2 forming a straight line via the similar Na-Na separations.