Layered exfoliable crystalline materials based on Sm-, Eu- and Eu/Gd-2-phenylsuccinate frameworks. Crystal structure, topology and luminescence properties

New layered 2D MOFs based on 2-phenylsuccinate, Sm, Eu and Eu/Gd are a suitable platform for obtaining exfoliatable frameworks with luminescence properties for potential applications as thin films.

Synthesis and Characterization of a New Mebendazole Salt: Mebendazole Hydrochloride

Mebendazole hydrochloride [(5-benzoyl-1H-benzimidazole-2-yl)-carbamic acid methyl ester hydrochloride, MBZ.HCl], a new stable salt of mebendazole (MBZ), has been synthesized and characterized. It can easily be obtained from recrystallization of forms A, B, or C of MBZ in diverse solvents with the addition of hydrochloric acid solution. Crystallographic data reveals that the particular conformation adopted by the carbamic group contributes to the stability of the network. The crystal packing is stabilized by the presence of three N-H...Cl intermolecular interactions that form chains along the b axis. The XRD analyses of the three crystalline habits found in the crystallization process (square-based pyramids, pseudohexagonal plates, and prismatic) show equivalent diffraction patterns. The vibrational behavior is consistent with crystal structure. The most important functional groups show shifts to lower or higher frequencies in relation to the MBZ polymorphs. The thermal study on MBZ.HCl indicates that the compound is stable up to 160 degrees C approximately. Decomposition occurs in four steps. In the first step the HCl group is eliminated, and after that the remaining MBZ polymorph A decomposes in three steps, as happens with polymorphs B and C. (

A low temperature infrared study of the coordinated water in calcium malonate dihydrate

The infrared spectra of calcium malonate dihydrate in the polycrystalline state, both normal and with different degrees of deuteration, were obtained at low temperatures in order to obtain information about the crystalline environment of the hydration water molecules. The study showed that both water molecules are non-equivalent and non-symmetric. That result is indicative of a non-symmetric space group for the crystal, in agreement with one out of three different crystallographic studies made on the substance.