Diverse Cyclization Pathways Between Nitriles with Active -Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding.

Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is in contrast to what we observed before for other nitriles.

Computational exploration of the copper(I)-catalyzed conversion of hydrazones to dihalogenated vinyldiazene derivatives.

This computational study explores the copper (I) chloride catalyzed synthesis of (E)-1-(2,2-dichloro-1-phenylvinyl)-2-phenyldiazene (2Cl-VD) from readily available hydrazone derivative and carbon tetrachloride (CCl). 2Cl-VD has been extensively utilized to synthesize variety of heterocyclic organic compounds in mild conditions. The present computational investigations primarily focus on understanding the role of copper (I) and N,N,N,N-tetramethylethane-1,2-diamine (TMEDA) in this reaction, TMEDA often being considered a proton scavenger by experimentalists.

Crystal structures and Hirshfeld surface analyses of methyl 4-{2,2-di-chloro-1-[()-phenyl-diazen-yl]eth-enyl}benzoate, methyl 4-{2,2-di-chloro-1-[()-(4-methyl-phen-yl)diazen-yl]ethen-yl}benzoate and methyl 4-{2,2-di-chloro-1-[()-(3,4-di-methyl-phen-yl)diazen-yl]ethen-yl}benzoate.

The crystal structures and Hirshfeld surface analyses of three similar azo compounds are reported. Methyl 4-{2,2-di-chloro-1-[()-phenyl-diazen-yl]ethen-yl}benzoate, CHClNO, (), and methyl 4-{2,2-di-chloro-1-[()-(4-methyl-phen-yl)diazen-yl]ethen-yl}benzoate, CHClNO, (), crystallize in the space group 2/ with = 4, and methyl 4-{2,2-di-chloro-1-[()-(3,4-di-methyl-phen-yl)diazen-yl]ethen-yl}benzoate, CHClNO, (), in the space group with = 2. In the crystal of (), mol-ecules are linked by C-H⋯N hydrogen bonds, forming chains with (6) motifs parallel to the axis.

Crystal structure and Hirshfeld surface analysis of 4-azido-2-(3,5-di-methyl-phen-yl)-5-(4-nitro-phen-yl)-2-1,2,3-triazole.

In the title compound, CHNO, the 3,5-di-methyl-phenyl and 4-nitro-phenyl rings are inclined to the central 2-1,2,3-triazole ring by 1.80 (7) and 1.79 (7)°, respectively, and to one another by 2.

Crystal structures and Hirshfeld surface analyses of ()-1-[1-(4--butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-phenyl-diazene, ()-1-[1-(4--butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-methyl-phen-yl)diazene, ()-1-[1-(4--butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-meth-oxy-phen-yl)diazene and ()-1-[1-(4--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. ()-1-[1-(4--Butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-phenyl-diazene, CHClN, (), and ()-1-[1-(4--butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-methyl-phen-yl)diazene, CHClN, (), crystallize in the monoclinic space group 2/ with = 8, and ()-1-[1-(4--butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-meth-oxy-phen-yl)diazene, CHClNO, (), in the monoclinic space group 2/ with = 4. ()-1-[1-(4--Butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(3-methyl-phen-yl)diazene, CHClN, (), crystallizes in the triclinic space group with = 4 and comprises two mol-ecules ( and ) in the asymmetric unit.

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.

Crystal structure and Hirshfeld surface analysis of a new polymorph of ()-2-(4-bromo-phen-yl)-1-[2,2-di-bromo-1-(3-nitro-phen-yl)ethen-yl]diazene.

A new polymorph of the title compound, CHBrNO, (form-2) was obtained in the same manner as the previously reported form-1 [Akkurt (2022 ▸). E, 732-736]. The structure of the new polymorph is stabilized by a C-H⋯O hydrogen bond that links mol-ecules into chains.

Crystal structure and Hirshfeld surface analysis of ()-2-(4-bromo-phen-yl)-1-[2,2-di-bromo-1-(4-nitro-phen-yl)ethen-yl]diazene.

The mol-ecule of the title compound, CHBrNO, consists of three almost planar groups: the central di-bromo-ethenyldiazene fragment and two attached aromatic rings. The mean planes of these rings form dihedral angles with the plane of the central fragment of 26.35 (15) and 72.

Crystal structure and Hirshfeld surface analysis of ()-1-[2,2-di-bromo-1-(4-nitro-phen-yl)ethen-yl]-2-(4-fluoro-phen-yl)diazene.

In the title compound, CHBrFNO, the 4-fluoro-phenyl ring and the nitro-substituted phenyl ring form a dihedral angle of 64.37 (10)°. Mol-ecules in the crystal are connected by C-H⋯O and C-H⋯F hydrogen bonds into layers parallel to (011).

Crystal structure and Hirshfeld surface analysis of ()-1-[2,2-di-bromo-1-(2-nitro-phen-yl)ethen-yl]-2-(4-fluoro-phen-yl)diazene.

In the title compound, CHBrFNO, the nitro-substituted benzene ring and the 4-fluoro-phenyl ring form a dihedral angle of 65.73 (7)°. In the crystal, mol-ecules are linked into chains by C-H⋯O hydrogen bonds running parallel to the -axis direction.

Crystal structure and Hirshfeld surface analysis of 3-[2-(3,5-di-methyl-phen-yl)hydrazinyl-idene]benzo-furan-2(3)-one.

In the title compound, CHNO, the 2,3-di-hydro-1-benzo-furan ring system is essentially planar and makes a dihedral angle of 3.69 (7)° with the di-methyl-phenyl ring. The mol-ecular conformation is stabilized by an intra-molecular N-H⋯O hydrogen bond with an (6) ring motif.

Crystal structure and Hirshfeld surface analysis of ()-1-[2,2-di-chloro-1-(4-fluoro-phen-yl)ethen-yl]-2-(2,4-di-chloro-phen-yl)diazene.

In the title compound, CHClFN, the dihedral angle between the 4-fluoro-phenyl ring and the 2,4-di-chloro-phenyl ring is 46.03 (19)°. In the crystal, the mol-ecules are linked by C-H⋯N inter-actions along the -axis direction, forming a (6) chain.

Crystal structure and Hirshfeld surface analysis of ()-4-({2,2-di-chloro-1-[4-(di-methyl-amino)-phen-yl]ethenyl}diazen-yl)benzo-nitrile.

In the title compound, CHClN, the dihedral angle between the aromatic rings is 50.09 (9)°. The central -N=N- unit shows an configuration.

Crystal structure and Hirshfeld surface analysis of ()-1-[2,2-di-chloro-1-(4-methyl-phen-yl)ethen-yl]-2-(4-meth-oxy-phen-yl)diazene.

The asymmetric unit of the title compound, CHClNO, comprises two similar mol-ecules, and , in which the dihedral angles between the two aromatic rings are 70.1 (3) and 73.2 (2)°, respectively.

Crystal structure and Hirshfeld surface analysis of (2)-,-dimethyl-2-(penta-fluoro-phen-yl)-2-(2-phenyl-hydrazin-1-yl-idene)acetamide.

In the title compound, CHFNO, the dihedral angle between the aromatic rings is 31.84 (8)°. In the crystal, the mol-ecules are linked into dimers possessing crystallographic twofold symmetry by pairwise N-H⋯O hydrogen bonds and weak C-H⋯O hydrogen bonds and aromatic π-π stacking inter-actions link the dimers into a three-dimensional network.

Crystal structure and Hirshfeld surface analysis of 1,3-bis-{2,2-di-chloro-1-[()-phenyl-diazen-yl]ethen-yl}benzene.

In the mol-ecule of the title compound, CHClN, the central benzene ring makes dihedral angles of 77.03 (9) and 81.42 (9)° with the two approximately planar 2,2-di-chloro-1-[()-phenyl-diazen-yl]vinyl groups.

Halogenated Diazabutadiene Dyes: Synthesis, Structures, Supramolecular Features, and Theoretical Studies.

Novel halogenated aromatic dichlorodiazadienes were prepared via copper-mediated oxidative coupling between the corresponding hydrazones and CCl. These rare azo-dyes were characterized using H and C NMR techniques and X-ray diffraction analysis for five halogenated dichlorodiazadienes. Multiple non-covalent halogen···halogen interactions were detected in the solid state and studied by DFT calculations and topological analysis of the electron density distribution within the framework of Bader's theory (QTAIM method).

()-1-(2,6-Di-chloro-phen-yl)-2-(3-nitro-benzyl-idene)hydrazine: crystal structure and Hirshfeld surface analysis.

The stabilized conformation of the title compound, CHClNO, is similar to that of the isomeric compound ()-1-(2,6-di-chloro-phen-yl)-2-(2-nitro-benzyl-idene)hydrazine. The 2,6-di-chloro-phenyl ring and the nitro-substituted benzene ring form a dihedral angle of 26.25 (16)°.

Crystal structure and Hirshfeld surface analysis of ()-4-{2,2-di-chloro-1-[(3,5-di-methyl-phen-yl)diazen-yl]ethen-yl}-,-di-methyl-aniline.

In the title compound, CHClN, the planes of the benzene rings subtend a dihedral angle of 77.07 (10)°. In the crystal, mol-ecules are associated into inversion dimers short Cl⋯Cl contacts [3.

Crystal structure and Hirshfeld surface analysis of ()-1-(2,6-di-chloro-phen-yl)-2-(2-nitro-benzyl-idene)hydrazine.

In the title compound, CHClNO, the 2,6-di-chloro-phenyl ring and the nitro-substituted benzene ring form a dihedral angle of 21.16 (14)°. In the crystal, face-to-face π-π stacking inter-actions occur along the axis direction between the centroids of the 2,6-di-chloro-phenyl ring and the nitro-substituted benzene ring.

Crystal structure and Hirshfeld surface analysis of 4-{2,2-di-chloro-1-[()-2-(4-methyl-phen-yl)diazen-1-yl]ethen-yl}-,-di-methyl-aniline.

In the tile compound, CHClN, the dihedral angle between the benzene rings is 62.73 (9)°. In the crystal, there are no classical hydrogen bonds.

Crystal structure and Hirshfeld surface analysis of 4-{2,2-di-chloro-1-[()-(4-chloro-phen-yl)diazen-yl]ethen-yl}-,-di-methyl-aniline.

The title compound, CHClN, comprises three mol-ecules of similar shape in the asymmetric unit. The crystal cohesion is ensured by inter-molecular C-H⋯N and C-H⋯Cl hydrogen bonds in addition to C-Cl⋯π inter-actions. Hirshfeld surface analysis and two-dimensional fingerprint plots reveal that Cl⋯H/H⋯Cl (33.

Crystal structure and Hirshfeld surface analysis of 4-{2,2-di-chloro-1-[()-(4-fluoro-phen-yl)diazen-yl]ethen-yl}-,-di-methyl-aniline.

In the title compound, CHClFN, the dihedral angle between the two aromatic rings is 64.12 (14)°. The crystal structure is stabilized by a short Cl⋯H contact, C-Cl⋯π and van der Waals inter-actions.

Crystal structures and Hirshfeld surface analyses of the two isotypic compounds ()-1-(4-bromo-phen-yl)-2-[2,2-di-chloro-1-(4-nitro-phen-yl)ethen-yl]diazene and ()-1-(4-chloro-phen-yl)-2-[2,2-di-chloro-1-(4-nitro-phen-yl)ethen-yl]diazene.

In the two isotypic title compounds, CHBrClNO, (), and CHClNO, (), the substitution of one of the phenyl rings is different [Br for () and Cl for ()]. Aromatic rings form dihedral angles of 60.9 (2) and 64.

Crystal structure and Hirshfeld surface analysis of ()-4-{[2,2-di-chloro-1-(4-meth-oxy-phen-yl)ethen-yl]diazen-yl}benzo-nitrile.

In the title compound, CHClNO, the 4-meth-oxy-substituted benzene ring makes a dihedral angle of 41.86 (9)° with the benzene ring of the benzo-nitrile group. In the crystal, mol-ecules are linked into layers parallel to (020) by C-H⋯O contacts and face-to-face π-π stacking inter-actions [centroid-centroid distances = 3.