Crystal structure and characterization of the sulfamethazine-piperidine salt

Sulfamethazine [N1-(4,6-dimethylpyrimidin-2-yl)sulfanilamide] is an antimicrobial drug that possesses functional groups capable of acting as hydrogen-bond donors and acceptors, which make it a suitable supramolecular building block for the formation of cocrystals and salts. We report here the crystal structure and solid-state characterization of the 1:1 salt piperidinium sulfamethazinate (PPD+center dot SUL, C5H12N+center dot C12H13N4O2S-) (I). The salt was obtained by the solventassisted grinding method and was characterized by IR spectroscopy, powder X-ray diffraction, solid-state C-13 NMR spectroscopy and thermal analysis [differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)]. Salt I crystallized in the monoclinic space group P21/n and showed a 1:1 stoichiometry revealing proton transfer from SUL to PPD to form salt I. The PPD+ and SUL ions are connected by N-H+...O and N-H (+)...N interactions. The self-assembly of SUL anions displays the amine-sulfa C(8) motif. The supramolecular architecture of salt I revealed the formation of interconnected supramolecular sheets.

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This article reports the crystal structure and solid-state characterization of the 1:1 salt piperidinium sulfamethazinate. The salt exhibits hydrogen-bond donors and acceptors, which allows for the formation of supramolecular structures. The crystal structure of the salt reveals proton transfer between sulfamethazine and piperidinium ions, connected by N-H+...O and N-H (+)...N interactions. The self-assembly of sulfamethazine anions forms amine-sulfa C(8) motifs, and the supramolecular architecture displays interconnected sheets.