Direct current atmospheric pressure glow discharge (dc‐APGD), generated between a pin‐type tungsten solid cathode and the surface of a flowing liquid anode (FLA), was used to synthesize Ag nanoparticles (AgNPs) and gelatin‐stabilized Ag nanoparticles (GEL‐AgNPs) in a flow‐through plasma‐reaction system. To characterize the nanostructures, UV/Vis absorption spectrophotometry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were applied. Resulting GEL‐capped AgNPs were more stable and lower in size than AgNPs. By applying attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT‐IR) and FT‐Raman spectroscopy, possible functionalization of the AgNPs surface by GEL after dc‐APGD treatment was examined. The described method was robust and provided high amounts of the suspensions of nanocolloidal Ag.

Benznidazole, the primary drug used in Chagas’ disease treatment, has known side effects, which may limit its widespread use. Its low solubility could negatively interfere in the bioavailability, even accentuating the toxic effects. Cocrystals have been extensively used to modify and optimize physicochemical properties, but, as single-component raw materials, they are susceptible to the phenomenon of polymorphism. In this work, we report a trimorphic cocrystal containing a 1:1 ratio of benznidazole and salicylic acid. The crystalline structures of three polymorphs were elucidated by single-crystal X-ray diffraction. Moreover, several isostructural solvates were also synthesized and analyzed. The same carboxylic acid-imidazole supramolecular heterosynthon is present in the four forms, but the main structural feature is an extended column based on amide–amide hydrogen bonds. On the basis of the crystalline structures, the trimorphic system was classified as conformational and packing polymorphism. Furthermore, the dissolution profiles of the stable forms were determined and showed a significant solubility improvement over the raw material.

Two new polymorphic forms of 5-nitrofurazone (5-nitro-2-furaldehyde semicarbazone) have been synthesized and structurally characterized by single-crystal and powder X-ray diffraction methods, vibrational spectroscopy (FT-IR and temperature Raman), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Hirshfeld surface analysis. The compound crystallizes in three different polymorphic forms P21/a (polymorph α), P21 (polymorph β) and P21/c (polymorph γ), the crystal structures of two of which (polymorphs β and γ) represent new structure determinations. The solid-state molecular organization in the three crystal forms is analyzed and discussed in terms of molecular conformation, crystal packing and hydrogen-bonded networks. All three crystals are formed from trans geometrical isomers, but the molecular conformation of the α-polymorph is syn-anti-anti-anti, while that of β- and γ-polymorphs is syn-anti-syn-syn. As a consequence of this the hydrogen-bond donor and acceptor sites of the molecules are oriented differently, which in turn results in different hydrogen-bond connectivity and packing patterns.

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