73014-98-9Relevant academic research and scientific papers
Exploiting the Role of Molecular Electrostatic Potential, Deformation Density, Topology, and Energetics in the Characterization of S?N and Cl?N Supramolecular Motifs in Crystalline Triazolothiadiazoles
Khan, Imtiaz,Panini, Piyush,Khan, Salah Ud-Din,Rana, Usman Ali,Andleeb, Hina,Chopra, Deepak,Hameed, Shahid,Simpson, Jim
, p. 1371 - 1386 (2016/03/12)
A detailed analysis of the molecular and crystal packing of a series of pharmaceutically active triazolothiadiazole derivatives is reported. The most notable feature from the analysis of the supramolecular motifs is the presence of inversion dimers due to the formation of strong S?N chalcogen bonds. This has been unequivocally established via inputs from energy calculations from PIXEL, the topological analysis using the approach of QTAIM from AIMALL, an analysis of the molecular electrostatic potentials plotted on Hirshfeld surfaces, and the analysis of the 3D-deformation densities obtained using Crystal Explorer. The total interaction energy for this contact is in the range of 28-33 kJ/mol in the molecules under investigation, and the electrostatic (Coulombic + polarization) contribution toward the total stabilization energy is more than 70%, indicating that such interactions are principally electrostatic in origin. The results from the analysis of the molecular ESP depict that this interaction exists between a strongly electropositive σ-hole on the sulfur atom and an electronegative region on the nitrogen. 3D-deformation density (DD) maps reveal the presence of a charge depletion (CD) region on the sulfur atom which is directed toward the charge concentration (CC) region on the nitrogen atom facilitating formation of such contacts in the crystal. These are further invesigated by QTAIM based calculations which establish the closed-shell nature of these contacts. The crystal packing is further stabilized by the presence of significantly important π?π stacking interactions, wherein the interaction energies, calculated by the PIXEL method, reveal that some of these interactions in crystals have significant contributions from electrostatic components, with a lesser contribution from dispersion forces that normally dominate such interactions. The existence of a contribution of ～48% from electrostatics between stacked rings owing to their unique electrostatic complementarity is a rare supramolecular feature observed in crystal packing in these solids. In addition, the existence of C-H?O, C-H?N, C-H?F, and Cl?N interactions is also characterized by a significant electrostatic component in their formation in crystals of these compounds.
Silica-supported dichlorophosphate as a recoverable cyclodehydrant: Expeditious synthesis of [1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles under microwave irradiation
Li, Zheng,Zhao, Yanlong
experimental part, p. 3816 - 3824 (2009/12/08)
An expeditious novel approach to 3,6-disubstituted [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazoles using silica-supported dichlorophosphate as a recoverable cyclodehydrant, carboxylic acids and thiocarbohydrazide as starting materials, and microwave irradiatio
Synthesis and biological activity of 3-(2-furanyl)-6-aryl-1,2,4-triazolo[3, 4-b]-1,3,4-thiadiazoles
Zhang, Li-Xue,Zhang, An-Jiang,Chen, Xian-Xing,Lei, Xin-Xiang,Nan, Xiang-Yun,Chen, Dong-Yong,Zhang, Zi-Yi
, p. 681 - 689 (2007/10/03)
3-(2-Furanyl)-4-amino-5-mercapto-1,2,4-triazole (1) was prepared from 2-furoic acid through a multi-step reaction sequence. Compound 1 reacted with aromatic acids in the presence of phosphorus oxychloride to give 3-(2-furanyl)-6-aryl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles (2). The structures of all the newly synthesized compounds have been confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR and mass spectra. The bioassay indicated most of the title compounds possess significant growth promoting effects on mung bean radicles.
