Synthesis, structure, and properties of a coordination polymer based on N- and O-donors

A ternary coordination polymer, [Cd(L)(pbda)(0.5)](n) [HL = 3,5-bis(2-pyridylmethyl) aminobenzoic acid, pbda = dianion of 1,4-benzenedicarboxylic acid], has been synthesized and characterized by elemental analysis, FT-IR spectroscopy, powder X-ray diffraction, thermogravimetric analysis, and single-crystal X-ray diffraction analysis. The single-crystal X-ray crystallography reveals that the complex is a 2-D wave-like network. The cadmium has an unsymmetrical seven-coordinate [CdN2O5] geometry, coordinated by two nitrogens and five oxygens from L- and pbda. Hydrogen bonds between the uncoordinated (2-pyridylmethyl) amino groups from adjacent layers form dimers across the inversion center, superposing different layers to construct a 3-D framework. To the best of our knowledge, [Cd(L)(pbda)(0.5)](n) represents the first example of a complex containing 3,5-bis(2-pyridylmethyl) aminobenzoate.