A new mixed-metal Ag-Co coordination polymer assembled from cobalt-containing molecular building blocks and AgNO3

The cobalt-containing molecular building block Co(2-pyrazinecarboxylatO)(2).(H2O)(2) (1) was prepared and used in the synthesis of a new mixed metal organic-inorganic polymeric material. The reaction between 1 and AgNO3 resulted in the formation of [Ag[Co(pyzca)(2)(H2O)(NO3)]}(n) (2, orthorhombic. Pbca; a = 12.9991(9), b = 7.7977(5), c = 27.7847(17) Angstrom, Z = 8), where Co(C5H3N2O2)(2)(H2O)(NO3) building blocks are linked by Ag atoms into a one-dimensional linear chain structure. The chains are linked into a three-dimensional framework via weak Ag+...(NO3)(-) interactions and "bifurcated" hydrogen bonds. The new coordination polymer exhibits thermal stability up to 200degreesC. The magnetic susceptibility for 2 follows the Curie law, with no indication of long range magnetic order. Synthesis, X-ray structure determination, thermogravimetric analysis and magnetic properties are presented. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.