3D Structure of N-Benzenesulfonyl-1H-1,2,3-benzotriazole. Single Crystal X-Ray Diffraction and DFT Studies

KOMROVSKY F; SPERANDEO NR; VERA DMA; CAIRA MR; MAZZIERI MR

Congreso; I Reunión Latinoamericana de Cristalografía - IX Reunión Anual de la AACr; 2013

As part of an ongoing research project on orphan drugs, a library of N-benzenesulfonyl derivatives of heterocycles has been prepared, some of which have presented interesting antiparasitic [1, 2], and antibacterial [3] activities. Herein we report the crystal structure of N-benzenesulfonyl-1H-1,2,3-benzotriazole (1), that has an interesting in vitro activity on Trypanosoma cruzi epimastigote and trypomastigote forms [4]. Also, the calculated structure by the DFT/B3LYP/6-311+G(2d,p) method was used for comparison. Single crystals of 1 were obtained by the vapor diffusion method. It crystallizes in the triclinic space group P-1 (Nº 2) with two inversion-related molecules in the unit cell. Its overall molecular conformation can be described by two torsion angles, namely φ1 (N2-N1-S10-C13) = -94.6(2) and φ2 (N1-S10-C13-C14) = 84.2(3). Prominent interactions in the crystal include two intermolecular hydrogen bonds (C6-H6O12 and C7-H7O11) and three  interactions with ring-centroidring-centroid distances ranging from ~3.6-3.7Å. There is a distinctive C-HO hydrogen bonding network in the crystal that forms infinite ribbons of molecules that run parallel to the crystal c-axis. The X-ray structure of the close analogue, N-(4-methylbenzenesulfonyl)-1H-1,2,3-benzotriazole, showed a similar motif [5]. The minimum energy structures found by theoretical calculations showed φ1 = -67.6° and φ2 = 88.0° in vacuo; however, in water, the angles were -77.5° and 88.7°, respectively. These large differences in φ1, when comparing both calculated conformations with that in the solid state (φ1 solid state-vacuum: 27° and φ1 solid state-water: 17.1°), could originate from the high intermolecular cohesive forces present in the crystal structure.