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Three salts: 3-amino-1,2,4-triazolinium (1+) hydrogen oxalate ( 1 ), 3-amino-1,2, 4-triazolinium (1+) hydrogen malonate ( 2 ), 3-amino-1,2,4-triazolinium (1+) hydrogen succinate ( 3 ) and one co-crystal: 3-amino-1,2,4-triazole-adipic acid ( 4 ) have been prepared and characterized by differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), IR, Raman, and single-crystal X-ray diffraction. Wherein, supramolecular motif in salts 1 , 3 and co-crystal 4 were dominant by triazole-acid and amino-acid heterosynthon, while salt 2 dominant by amino-triazole homosynthon in addition to triazole-acid heterosynthon, which attribute to the intermolecular hydrogen interactions within hydrogen malonate anion. These results have a close relationship with the ΔpKa between 3-ATZ and alkyl acids, we found that the ΔpKa is grate than 6.9, the formation of salt will be expected, while the formation of co-crystal usually with the ΔpKa less than 6.75. It is interesting that salts 2 and 3 show the phenomenon of proton transfer after melt, which lead to the stepwise sublimation of the two components. The differences between salts and co-crystal were also revealed by the solid-state vibrational spectroscopy (IR and Raman), Hirshfeld surface analysis and UV spectra. [ABSTRACT FROM AUTHOR]

Crystal structural investigations and Hirshfeld surface analysis of three methoxy- and methyl-substituted indole-3-acetonitriles (IAN) (4-OCH-IAN, 5-OCH-IAN and 7-CH-IAN) are reported in this work. Their structures were characterized by infrared spectra, elemental analyses, NMR spectra, differential scanning calorimetry, thermogravimetric analyses, and hot stage microscopy. The Hirshfeld surface analysis in terms of intermolecular interactions and π···π stacking motifs of the three substituted IANs was investigated in detail, and the results revealed that the different kinds of substituent groups as well as different substituted positions have a significant effect on the crystal structures, molecular π···π stacking motifs, melting points, and the types of intermolecular interactions. [ABSTRACT FROM AUTHOR]

Crystal structural investigations and Hirshfeld surface analysis of three halogen atoms (4-Cl, 6-Cl and 4-Br) substituted indole-3-acetonitrile (IAN) were reported in this work. The structures of the present three compounds were characterized by Infrared spectra, Elemental analyses, NMR spectra, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and hot stage microscopy (HSM). The Hirshfeld surfaces analysis in terms of crystal structure, intermolecular interactions and π⋯π stacking motifs were performed. We found that the different kinds of halogen atoms and the different substituted positions have a significant effect on the crystal structures, molecular π⋯π stacking motifs, melting points, and the nature of intermolecular interactions for IANs. [ABSTRACT FROM AUTHOR]

For the development of dispersible tablets of itraconazole (ITR), techniques of thermal, Raman spectroscopy, and isothermal stress testing (IST) were used to assess the compatibility of ITR with selected excipients. Initially, differential scanning calorimeter (DSC) was used to evaluate the compatibility. Raman spectrum of drug-excipient mixture was also compared with that of pure drug and excipient. Compatibility of excipients defined in the prototype formula was tested using IST. Based on the DSC results alone, PEG-4000 was found to exhibit interaction with ITR. However, the results of Raman and IST studies showed that all the excipients used in the formula were compatible with ITR. Overall, compatibility of excipients with ITR was successfully evaluated using the combination of DSC, Raman spectroscopy, and IST techniques. [ABSTRACT FROM AUTHOR]

An investigation into the substituent effect of halogen atoms (F, Cl, Br) on the crystal structure of indole-3-carboxylic acid (ICA) was prepared in this work. The investigation was done through the aspect of crystal structure, intermolecular interactions and π…π stacking motifs with the assistance of infrared spectra, elemental analyses, NMR spectra, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and hot stage microscopy (HSM) measurements. The results revealed that the different kinds of halogen atoms and the different substituted positions have a significant effect on the crystal structures, molecular π…π stacking motifs and the kinds of intermolecular interactions. We further correlated the melting points of the ICAs with the H–H, O–H and X–H (X = F, Cl, Br) interactions, and found a positive correlation between them. [ABSTRACT FROM AUTHOR]

In the present study, the assembly of 6-aminonicotinic acid with inorganic acids (HBr, HNO 3 and H 3 PO 4 ) has been performed, which resulted in the molecular salts C 6 H 7 N 2 O 2 + ·Br − ( 1 ), C 6 H 7 N 2 O 2 + ·NO 3 − ( 2 ) and C 6 H 7 N 2 O 2 + ·H 2 PO 4 − ( 3 ), respectively. These three molecular salts have been characterized by single-crystal X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and UV–Vis absorption spectroscopy (UV). The results revealed that molecular salt 1 exhibits an infinite 1-D chain structure stabilized mainly by N–H⋯Br contacts, while 2 and 3 show a 2-D network and a 3-D stereoscopic framework, respectively, which are stabilized mainly by strong N–H⋯O hydrogen bonding contacts. Hirshfeld surface analysis demonstrated the presence of H⋯H, O–H⋯N, C–H⋯π and π⋯π intermolecular interactions. In addition, the UV–Vis spectra exhibit a slight blue-shift to a shorter wavelength, which suggests the clear influence of the inorganic anions. [ABSTRACT FROM AUTHOR]