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

Two new complexesCo_2(L)(4,4′-bip)(H_2O)_3]_n (1) and{Co(L′)_2(phen)]·2H_2O)}_n (2)(H_4L=1-(3,5-dicarboxybenzyl)-3,5-pyrazole dicarboxylic acid,H_3L′=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 2have 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.