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

Dimethyl 2,3-dihydroxyterephthalate is an important intermediate widely used in the synthesis of 1H,4H-benzo[2,1b:3,4-b0]bisthiete and 2H,3H-benzo[1,2-b:4,3-b0]bisthiete, which are very versatile reagents for the generation of polycyclic sulfur-containing compounds (Meier & Rumpf, 1998; Meier & Mayer, 1994) and macrobicyclic Fe sequestering agents (Garrett et al.,1991). The title compound, (I), of which we report the crystal structure here, can also be used directly to synthesize enterobactin analogues (Weitl et al., 1981).

Dimethyl 2,3‐dihydroxyterephthalate

The title compound, C13H11NO3, was synthesized from 4-nitro­phenol and benzyl bromide. The crystal structure is stabilized by C—H⋯π inter­actions involving two H atoms of the benzyloxy group [3.432 (2) A and 148°, and 3.555 (2) A and 148°].

1-Benzyloxy-4-nitrobenzene

In the title compound, [Cu(C4H2BrO4)2(C6H6N4)2], the central CuII atom lies on an inversion center and is six-coordinated in an octahedral geometry by four N atoms from two chelating biimidazole mol­ecules in the equatorial plane and two O atoms from two 2-bromo­fumarate ligands in the axial positions. O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds lead to a three-dimensional network.

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Bis(2,2'-biimidazole-κN,N')bis-(2-bromo-fumarato-κO)copper(II).

The title compound, C11H9NO5, was prepared by the reaction of 2-furan­acrylic acid and N-hy­droxy­succinimide. The mol­ecule consists of two approximately planar moieties, viz. a succinimide group and the rest of the mol­ecule [the largest deviations from the least-squares planes are 0.120 (1) and 0.210 (1) A, respectively]. The dihedral angle between these fragments is 63.70 (5)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds into two-dimensional nets.

https://journals.iucr.org/e/issues/2011/11/00/yk2020/yk2020.pdf

2,5-Dioxopyrrolidin-1-yl 3-(furan-2-yl)acrylate.

In the title compound, C14H20N2O5S·CH4O, the pyran­ose and pyridine rings are linked through an S atom. The pyran­ose ring has a normal chair conformation. An intra­molecular O—H⋯N hydrogen bond occurs. Inter­molecular O—H⋯O, N—H⋯O, O—H⋯N and weak C—H⋯O hydrogen bonding is present in the crystal structure.

https://journals.iucr.org/e/issues/2010/10/00/xu5024/xu5024.pdf

Hong-Ze Liang

Papers

Dimethyl 2,3‐dihydroxyterephthalate

1-Benzyloxy-4-nitrobenzene

Bis(2,2'-biimidazole-κN,N')bis-(2-bromo-fumarato-κO)copper(II).

2,5-Dioxopyrrolidin-1-yl 3-(furan-2-yl)acrylate.

6-Methyl-2-pyridyl N-acetyl-1-thio-β-d-glucosa-minide methanol monosolvate.