Synthesis, X-ray crystal structure, vibrational spectroscopy, DFT calculations, electronic properties and Hirshfeld analysis of (E) -4-Bromo-N'-(2,4-dihydroxy-benzylidene) benzohydrazide

In this work, a study of the photophysical properties in different solvents and at different pH values of a luminogenic compound with a donor–π–acceptor (D–π–A) structure was carried out. The compound (Z)-3-(4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl)-2-phenylacrylonitrile (2) was synthesized and characterized by SCXRD, FT-IR, 1H NMR, 13C NMR, EIMS, UV-Vis absorption and fluorescence. The SCXRD characterization reveals a monoclinic system, P21/c, with Z = 4 and an imidazole core having hydrogen bonding with respect to water molecules present in the asymmetric unit. It leads to a strong π–π-interaction in the solid state. The fluorescence λmax emission of the powder and thin film was observed at 563 nm and 540 nm respectively. Several degrees of positive solvatochromic fluorescence were observed due to different molecular conformations in various solvents. When the pH of the compound was changed with HCl or NaOH, a shift in the wavelength of emission was observed in a reversible manner. At pH 2, the λmax of emission was at 541 nm whereas at pH 14 there were two emissions at 561 nm and 671 nm. Due to their good emission in the solid state, compound 2 was tested as an emitting layer in OLEDs; the devices showed an acceptable performance with a luminance average of 450 cd m−2. The band gap was analyzed by optical absorption, cyclic voltammetry measurement and DFT calculations.

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Solvatochromism and pH effect on the emission of a triphenylimidazole-phenylacrylonitrile derivative: experimental and DFT studies

Corrosion inhibition performance of 4-(prop-2-ynyl)- [1,4]-benzothiazin-3-one against mild steel in 1 M HCl solution: Experimental and theoretical studies

A detailed experimental and theoretical investigation on the intermolecular interactions in (Z)-3-(4-halophenyl)-2-(pyridin-2/3/4-yl)acrylonitriles is reported. The intermolecular interactions are analyzed and quantified by PIXEL, DFT and quantum theory of atoms in molecules (QTAIM) calculations. The results showed that the absence of strong classical hydrogen bonds and the presence of several weak intermolecular C–H⋯N, C–H⋯halogen, halogen⋯halogen and π stacking interactions play important roles in the stabilization of crystal structures. Four different π stacking dimers (homo parallel, homo slipped parallel, hetero anti-parallel and hetero anti-parallel slipped) are observed and found to be the most stabilized dimeric motifs in all structures. The hetero anti-parallel (−10.6 kcal mol−1) and slipped anti-parallel (−9.1 kcal mol−1) π⋯π interactions have the highest stabilization energies among the other interactions observed in the present study. The substituted halogen atoms (X = F, Cl and Br) are involved in the variant and invariant C–H⋯X, C⋯X and halogen⋯halogen interactions in all three families. The relative contributions of various non-covalent interactions are calculated using Hirshfeld surface analysis and 2D fingerprint plots. Further, detailed UV-vis spectral studies are reported for the title compounds in solution and solid phases. These results are compared with the simulated spectra and good agreement is found between experimental and theoretical spectra.

Quantitative analysis of weak non-covalent interactions in (Z)-3-(4-halophenyl)-2-(pyridin-2/3/4-yl)acrylonitriles

Theoretical investigations of two adamantane derivatives: A combined X-ray, DFT, QTAIM analysis and molecular docking

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Crystal structure, Hirshfeld surfaces and DFT computation of NLO active (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid.

In the title compound, C12H18N4O2, unlike other unconjugated disubstituted biimidazole derivatives reported so far, the two imidazole rings in a trans conformation exhibit a large planar rotation angle of 51.27 (4)°, and consist of half-mol­ecule asymmetric units related by a twofold rotation. The mol­ecules are linked into a three-dimensional framework with a parallel laminated construction via O—H⋯N and C—H⋯O inter­actions.

https://journals.iucr.org/e/issues/2009/02/00/at2693/at2693.pdf

3,3'-(2,2'-Bi-1H-imidazole-1,1'-diyl)dipropanol.

In the title compound, C10H10N4O4, the two imidazole rings adopt a trans conformation and are inclined to one another at a dihedral angle of 55.64 (4)°. In the crystal structure, mol­ecules are linked by inter­molecular O—H⋯N hydrogen bonds into chains running parallel to [010] and layers are formed from these by inter­molecular C—H⋯O hydrogen bonds. Additional C—H⋯O hydrogen bonds produce a three-dimensional network.

https://journals.iucr.org/e/issues/2009/04/00/sj2599/sj2599.pdf

2,2'-(2,2'-Biimidazole-1,1'-di-yl)diethanoic acid.

In the crystal structure of the title compound, C15H16O2S, the thio­phene ring is essentially planar (r.m.s. deviation = 0.006 A for all non-H atoms) and roughly coplanar with the benzene ring, the dihedral angle between the mean planes of the rings being 4.35 (8)°. An intra­molecular O—H⋯O hydrogen bond is observed between the OH group and the aldehyde O atom.

https://journals.iucr.org/e/issues/2010/09/00/zq2050/zq2050.pdf

5-tert-Butyl-2-hy-droxy-3-(2-thien-yl)benzaldehyde.

The dinuclear title compound, [Co2(C10H8N4O4)2(H2O)4]·6H2O, lies about an inversion centre. Each CoII atom is six-coordinated by two water mol­ecules, two carboxyl­ate O atoms and two N atoms of two symmetry-related 2,2′-bi-1H-imidazole-1,1′-diacetate (L2−) ligands in a slightly distorted octa­hedral geometry. Mol­ecules are linked into a three-dimensional framework via O—H⋯O and C—H⋯O hydrogen bonds.

https://journals.iucr.org/e/issues/2009/05/00/sj2607/sj2607.pdf

Hong-Ze Liang

Papers

Crystal structure, Hirshfeld surfaces and DFT computation of NLO active (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid.

3,3'-(2,2'-Bi-1H-imidazole-1,1'-diyl)dipropanol.

2,2'-(2,2'-Biimidazole-1,1'-di-yl)diethanoic acid.

5-tert-Butyl-2-hy-droxy-3-(2-thien-yl)benzaldehyde.

Bis(μ-2,2'-bi-1H-imidazole-1,1'-di-acet-ato)bis-[diaqua-cobalt(II)] hexa-hydrate.