Two Co(Ⅱ)Complexes Constructed from 1-(3,5-Dicarboxybenzyl)-3,5-pyrazole Dicarboxylic Acid:Syntheses,Structures and Magnetic Properties

Two new complexes[Co_(2)(L)(4,4´-bip)(H_(2)O)_(3)]_(n)(1)and{[Co(L´)_(2)(phen)]·2H_(2)O)}_(n)(2)(H_(4)L=1-(3,5-dicarboxybenzyl)-3,5-pyrazole dicarboxylic acid,H_(3)L´=1-(3,5-dicarboxybenzyl)-3-pyrazole carboxylic acid,4,4´-bip=4,4´-bis(1-imidazolyl)biphenyl,phen=1,10-phenanthroline)were synthesized.Complexes 1 and 2 have been characterized by IR spectrography,X-ray single-crystal diffraction,elemental analysis and thermogravimetry.1 crystallizes in monoclinic system,space group P2_(1/c).Complex 2 crystallizes in monoclinic system,space group I2/a.It is remarkable that in situ hydrothermal decarboxylation was observed during preparing complex 2.In addition,magnetic analysis indicates that antiferromagnetic interaction exists among Co(Ⅱ)ions in complexes 1 and 2.