Sven Nerdinger

Vinylimidazolium salts constitute a highly relevant class of polymerizable heterocycles, especially in the field of so-called polymer ionic liquids (PILs), and they are frequently used as components of polyelectrolytes. Therefore, crystallographic characterizations, in particular studies of charge distribution and conformational features, can provide fundamental insights concerning ion–ion and ion–dipole interactions. The structure of the title compound [1046127-79-0] has the space group symmetry P2₁/c. Its asymmetric unit contains one formula unit, consisting of two bromide anions and the halves of two cation moieties. The cation units possess inversion symmetry, and their C₆H₁₂ chains adopt an all-trans conformation.

Two daprodustat solvate classes with distinct desolvation pathways are established. Solvate intermediates were found to form under elevated humidity and/or temperature conditions.

The dihydrochloride salt of pexidartinib was synthesized and the crystal structure of its dihydrate was determined from single crystal data. The asymmetric unit consists of one formula unit. In the pexidartinib molecule, the N atom of the central pyridine ring and the pyridine-N atom of the pyrrolopyridine group are both protonated. The pexidartinib molecule forms N–H···O and N–H···Cl interactions with neighboring water molecules and chloride ions, respectively. Water/chloride (O–H···Cl) and water/water (O–H···O) interactions are also observed. Collectively, these intermolecular interactions result in a complex H-bonded framework structure.

The molecule of the title compound adopts a twisted geometry with a rotation of approximately 30° between the mean planes of the imidazole and phenyl rings. The crystal structure displays hydrogen bonded chains as a result of N–H···N interactions between the imidazole rings of neighboring molecules. These H-bonded chains are assembled into flat molecular layers parallel to the (121) plane. Two intermolecular interactions, involving inversion-related molecules belonging to adjacent molecular layers, contribute significantly to the stabilization of the crystal.

The title compound, 2,6-diamino-5-[(2-cyclopropyl-7,8-dimethoxy-2H-1-benzopyran-5-yl)methyl]pyrimidin-1-ium methanesulfonate, C₁₉H₂₃N₄O₃ ⁺·CH₃O₃S⁻, is a salt made up from a protonated iclaprim molecule and a mesylate anion. The pyrimidine and chromene units of the iclaprim molecule form an orthogonal arrangement [interplanar angle of 89.67 (6)°], and the 3-nitrogen position of the pyrimidine ring is protonated. Four distinct N—H...O interactions and an additional N—H...N hydrogen bond connect iclaprim and mesylate molecules to one another, resulting in an infinite hydrogen-bonded molecular tape structure. The central section of the tape is formed by a sequence of fused hydrogen-bonded rings involving four distinct ring types.

3-(1H,1H,2H,2H-Perfluorooctyl)-1-vinylimidazolium chloride [2126844–17–3], a strong fluorosurfactant with remarkably high solubility in water, was expediently converted into the respective doubly NHC-complexed silver salt with nitrate as counter ion in quantitative yield. Due to its vinyl substituents, [bis(3-(1H,1H,2H,2H-perfluorooctyl)-1-vinylimidazol-2-ylidene)silver(I)] nitrate, Ag(FNHC)₂NO₃, represents a polymerizable N-heterocyclic carbene transfer reagent, thus potentially offering simple and robust access to coordination polymers with crosslinking metal bridges. The compound was characterized by infrared and NMR spectroscopy, mass spectrometry as well as elemental analysis, and supplemented by X-ray single-crystal structure determination. It crystallizes in the monoclinic crystal system in the space group P2₁/c. With 173.3°, the geometry of the Ag-carbene bridge deviates slightly from linearity. The disordered perfluoroalkyl side chains exhibit a helical conformation.