Synthesis, crystal structures and magnetic properties of three new 4-cyanobenzoate complexes

Three new 4-cyanobenzoate coordination complexes have been prepared, and their structures have been characterized by single-crystal X-ray diffraction. In [Cd(4-cba)2(py)2(H2O)] 1 and [Mn(4-cba)2(phen)(H2O)2] 2 (4-Hcba = 4-cyanobenzoic acid, py = pyridine, phen = 1 10-phenanthroline), carboxylate groups exhibit chelated bidentate and terminal monodentate coordination modes, respectively, to give discrete mononuclear units, which are linked by hydrogen bonds and face-to-face π − π stacking interactions to produce a 2-D supramolecular network. In [Mn(4- cba)2(H2O)2]n 3, the Mn(II) atoms are bridged by carboxylate groups of 4-cba ligands in the syn-skew bidentate mode in two directions to form a 2-D grid-like framework with a (4, 4) topology, and there also exist hydrogen bonds and face-to-face π–π stacking interactions in the layers. Variable-temperature magnetic susceptibility data show the presence of weak antiferromagnetic interactions with θ = −1.13(5) K in 2 and significant antiferromagnetic ordering (TN = 7.0 K) with θ = −11.40(5) K in 3. The thermogravimetric analyses of the three complexes have also been discussed.