Arylhydrazones of α-keto esters via methanolysis of dichlorodiazabutadienes: synthesis and structural study

Crystal structures and Hirshfeld surface analyses of (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-phenyl-diazene, (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-methyl-phen-yl)diazene, (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-meth-oxy-phen-yl)diazene and (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(3-methyl-phen-yl)diazene

The crystal structures and Hirshfeld surface analyses of four similar azo compounds are reported. (E)-1-[1-(4-tert-Butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-phenyl-diazene, C18H18Cl2N2, (I), and (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-methyl-phen-yl)diazene, C19H20Cl2N2, (II), crystallize in the monoclinic space group C2/c with Z = 8, and (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-meth-oxy-phen-yl)diazene, C19H20Cl2N2O, (III), in the monoclinic space group P21/c with Z = 4. (E)-1-[1-(4-tert-Butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(3-methyl-phen-yl)diazene, C19H20Cl2N2, (IV), crystallizes in the triclinic space group P with Z = 4 and comprises two mol-ecules (A and B) in the asymmetric unit. In the crystal structures of (I) and (II), mol-ecules are linked by C-H⋯π and C-Cl⋯π inter-actions, forming layers parallel to (02), while mol-ecules of (III) are linked by C-H⋯O contacts, C-H⋯π and C-Cl⋯π inter-actions forming layers parallel to (02). The stability of the mol-ecular packing is ensured by van der Waals forces between these layers. In the crystal structure of (IV), mol-ecules are linked by C-H⋯π and C-Cl⋯π inter-actions, forming a tri-periodic network.

Facile Access to 2-Selenoxo-1,2,3,4-tetrahydro-4-quinazolinone Scaffolds and Corresponding Diselenides via Cyclization between Methyl Anthranilate and Isoselenocyanates: Synthesis and Structural Features

A practical method for the synthesis of 2-selenoxo-1,2,3,4-tetrahydro-4-quinazolinone was reported. The latter compounds were found to undergo facile oxidation with H2O2 into corresponding diselenides. Novel organoselenium derivatives were characterized by the 1H, 77Se, and 13C NMR spectroscopies, high-resolution electrospray ionization mass spectrometry, IR, elemental analyses (C, H, N), and X-ray diffraction analysis for several of them. Novel heterocycles exhibited multiple remarkable chalcogen bonding (ChB) interactions in the solid state, which were studied theoretically.

Structural Organization of Dibromodiazadienes in the Crystal and Identification of Br···O Halogen Bonding Involving the Nitro Group

Nitro functionalized dibromodiazadiene dyes were prepared and fully characterized including X-ray single crystal analysis. Electron deficient dibromodiazadienes were found to be able to act as donors of halogen bonding (XB), while the nitro group acted as an acceptor of the XB. Depending on the substituents, the Br···O XB competed with other weak interactions, and for some of the dyes, they even outcompeted the XB involving the nitro group. However, the nitro functionalized dibromoalkenes 6a and 10a, which had only the nitro moiety as the most plausible acceptor of the XB, reliably formed 1D chains via Br⋯O XB. Experimental work was supported by the DFT calculations and topological analysis of the electron density distribution within the framework of Bader’s theory (QTAIM method).

Triarylazoimidazole-ZnII, CdII, and HgII Complexes: Structures, Photophysics, and Antibacterial Properties

Novel triarylazoimidazoles containing strong electron donors (p-NEt2) or acceptors (p-NO2) by the azoaryl group, and their group 12 metal complexes were synthesized and fully characterized, including X-ray analysis for several complexes. Novel complexes exhibit red photo-luminescence emission (Φ up to  0.21) in a solution. Moreover, the antibacterial activity of complexes was tested against Gram-positive microorganism S. aureus and Gram-negative microorganism E. coli.

Exploring Supramolecular Assembly Space of Cationic 1,2,4-Selenodiazoles: Effect of the Substituent at the Carbon Atom and Anions

Chalcogenodiazoles have been intensively studied in recent years in the context of their supramolecular chemistry. In contrast, the newly discovered cationic 1,2,4-selenodiazole supramolecular building blocks, which can be obtained via coupling between 2-pyridylselenyl halides and nitriles, are virtually unexplored. A significant advantage of the latter is their facile structural tunability via the variation of nitriles, which could allow a fine tuning of their self-assembly in the solid state. Here, we explore the influence of the substituent (which derives from the nitrile) and counterions on the supramolecular assembly of cationic 1,2,4-selenodiazoles via chalcogen bonding.