Reaction of isoniazid with benzoic acid, sebacic acid, suberic acid, and cinnamic acid results in formation of cocrystals. Two polymorphs of isoniazid–suberic acid and two polymorphs of isoniazid–cinnamic acid cocrystals were isolated. Crystal structure analysis shows the presence of a pyridine–carboxylic acid synthon in the studied cocrystals. The hydrazide group of isoniazid participates in N–H···O and N–H···N hydrogen bond formation, producing different supramolecular synthons. The stability study of isoniazid cocrystals has been performed over a 22 week period. A comparison of melting points of isoniazid–dicarboxylic acid 2:1 cocrystals shows the decrease of melting point with an increasing length of the acid. Solubility of isoniazid–carboxylic acid cocrystals tends to increase with increasing solubility of the acid.

Luminescent carbene−metal−amide complexes bearing group 11 metals (Cu, Ag, Au) have recently attracted great attention due to their exceptional emission efficiency and high radiative decay rates (k r ). These materials provide a less costly alternative to organic light-emitting diode (OLED) emitters based on more scarce metals, such as Ir and Pt. Herein, a series of eight Cu(I) complexes bearing as yet unexplored 1,3thiazoline carbenes have been investigated and analyzed with respect to their light emission properties and OLED application. For the first time among the class of copper-based organometallic compounds the formation of efficient electroluminescent excimers is demonstrated. The prevalence of electroluminescence (EL) from either the monomer (bluish green) or the excimer (orange-red) can be adjusted in vacuum-deposited emissive layers by altering the extent of steric encumbrance of the emitter or its concentration. Optimized conditions in terms of the emitter structure and mass fraction allowed a simultaneous EL from the monomer and excimer, which laid the basis for a preparation of a single-emitter white OLED (WOLED) with external quantum efficiency of 16.5% and a maximum luminance of over 40000 cd m −2 . Wide overlapping emission bands of the monomer and excimer ensure a device color rendering index (CRI) of above 80. In such a way the prospects of copper complexes as cost-effective materials for lighting devices are demonstrated, offering expense reduction through a cheaper emissive component and a simplified device architecture.

The cyclization of substituted diaryl(hetaryl)alkynes with in‐situ‐prepared SeBr4 has been achieved. The use of an alkene additive as a bromine scavenger gives simple access to functionalized benzo[b]selenophene and selenophenothiophene derivatives from commercially available or easily accessible starting materials. The reactions can be performed in air without the use of moisture‐sensitive reagents, dry solvents, or an inert atmosphere. Mechanistic studies confirmed a regioselective anti 1,2‐addition in the selenobromination step, and a subsequent electrophilic substitution in the aromatic ring to complete the cyclization.

Analysis of crystal structures, molecular properties, interaction strength in solution, and computationally generated nonsolvated form crystal structure landscapes of five chloronitrobenzoic acid isomers and two additional 2-substituted 4-nitrobenzoic acids were used to rationalize the obtained solvate landscape of these compounds. Screening of the solid forms was performed for each of the compounds, and crystal structures of the obtained nonsolvated forms and selected solvates were determined. Molecular conformation, intermolecular interactions, and packing efficiency of nonsolvated forms and solvates were analyzed to understand factors contributing to structure stabilization and determining the formation of the observed crystal structures. Computationally generated crystal structure landscapes of nonsolvated forms were tested for the possibility to predict the propensity to form solvates and identify polymorphic compounds. It was observed that most of the solvates were obtained with solvents acting as strong hydrogen bond acceptors and/or able to form aromatic interactions. Solute–solvent association Gibbs energy representing interaction strength was found to be the most apparent identifiable factor explaining the solvate formation of the studied compounds, and using this tool, the existence of 3 new multicomponent phases was successfully predicted.

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