Novel boron compounds of 2,3- and 2,5-pyridinedicarboxylic acids

The (Hea)[B(ph)2(2,3-pydc)] (1) and (Hea)[B(ph)2(2,5-pydc)] (2) boron compounds (2,3-H2pydc = 2,3-pyridinedicarboxylic acid, 2,5-H2pydc = 2,5-pyridinedicarboxylic acid, Hea = ethanolammonium) were synthesized and characterized by elemental analysis, spectroscopic measurements (UV–Vis, 11B NMR, 13C NMR, 1H NMR and IR spectra) and single crystal X-ray diffraction technique. Compound 1 and 2 crystallize in the monoclinic space group P21/c. The crystal packing of compound 1 is stabilized through strong intermolecular hydrogen bonding and C–H⋯π interactions, resulting in a 3D framework. The individual molecules of 2 are connected by the N–H⋯O and O–H⋯O hydrogen bonds leading to two-dimensional hydrogen bonded layer. The in vitro antibacterial and anticandidal activities of (1) and (2) were evaluated by disc diffusion method and MIC tests. Both new complexes showed antimicrobial activity against MRSA and clinical and standard yeast isolates.