Journal of Structural Chemistry

Nassri, A.; El Hammoumi, M. M.; El Bachiri, A.; El Youssfi, S.; Kandri Rodi, Y.; Touimi Benjelloun, A.

doi: 10.1134/s0022476624050019pmid: N/A

In this study, we investigate the reaction between water and the cis and trans limonene oxide mixture in the presence of ethyl carbamate ((R)-N-(α-methyl-benzyl)ethyl-carbamate), producing (1 R, 2 R, 4 R)-limonene-1,2-diol and trans limonene oxide. This study is carried out using the quantum mechanical density functional theory (DFT) method B3LYP-D3/6-31+G (d,p) to theoretically explain that 1,2-limonene diol is the hydrolysis product derived from cis limonene oxide, with trans limonene oxide not reacting (regioselectivity). For this reason, we exploit Fukui`s frontier molecular orbital theory (FMO), local softness and local hardness ratios, transition states of the obtained products, the Fukui indices, and the thermodynamic quantities (enthalpy, entropy, free energy calculations). The theoretical results effectively elucidate the observed regioselectivity and corroborate the experimental findings.[graphic not available: see fulltext]

Guo, Y.-N.; Hu, X.-B.; Zhang, H.-G.; Han, Y.-F.; Wang, H.

doi: 10.1134/s0022476624050020pmid: N/A

A new asymmetrical Schiff base ligand, (E)-4-chloro-2-{[(2,6-dimethylphenyl)amino] methyl}phenol (HL), and its mononuclear Cu(II) complex are synthesized. The molecular structures and spectroscopic properties of the ligand and its complex are experimentally characterized by single crystal X-ray diffraction, elemental analysis, FTIR, NMR and UV-Vis spectroscopic techniques. The analysis confirms that the Cu atom is generally four-coordinated in the complex by one imino N and one phenolic O atoms of the Schiff-base ligand, adopting a trans-configuration of N2O2 donor atoms around the metal ion, forming a square planar geometry. The density functional calculation is carried out for both HL and the copper(II) complex to investigate changes in the structural parameters and HOMO and LUMO energies. The results demonstrate that the HOMO and the LUMO are effectively separated by the benzene ring of 2,6-dimethylbenzenamine as a donor unit and the benzene ring of 5-chlorosalicylaldehyde as an acceptor unit. The effective HOMO–LUMO separation helps to induce intramolecular charge transfer from the HOMO to the LUMO. The HOMO–LUMO energy gap becomes smaller when the Schiff base ligand is coordinated with the Cu(II) ion, which is most likely to be due to the interaction of copper(II) d orbitals with the HOMO and/or LUMO of the ligand. These theoretical calculations support the experimentally observed results. The biological assay reveals that both the Schiff base and the complex have different antimicrobial activities. The complex has the MIC value of 0.0781 mmol/L against Escherichia coli.[graphic not available: see fulltext]

Zheng, Y.; Xu, Y.-L.; Ni, C.-L.

doi: 10.1134/s0022476624050032pmid: N/A

In this work, a new organic charge-transfer compound, namely 1-benzyl 2-aminopyridinium picrate [Bz-2-NH2Py][PIC] (1), is prepared and characterized by single crystal X-ray diffraction (SC-XRD), powder X-ray diffraction (PXRD), FTIR, 1H NMR and Raman spectroscopy. The title compound crystallizes in the monoclinic system with space group P2(1)/c and contains one [Bz-2-NH2Py]+ cation and one [PIC]– anion. The cations are stacked into a columnar structure through C–H⋯π interactions, and the N–H⋯O and C–H⋯O hydrogen bonds between the anions and cations stabilize the crystal stacking of [Bz-2-NH2Py][PIC] (1). The frontier molecular orbitals HOMO and LUMO are computed by the DFT approach (using the B3LYP/6-31G (d,p) basis set) to understand the chemical reactivity and kinetic stability of the title compound. The geometrical parameters obtained from the XRD experiment are in good agreement with the simulated values from the single crystal structure. In addition, the organic material shows two main emission peaks at about 390 nm and 469 nm upon 241 nm excitation in the solid state at room temperature. The Hirshfeld surface analysis is performed to quantify the contributions of different intermolecular interactions.[graphic not available: see fulltext]

Kryuchkova, N. A.; Stadnichenko, A. I.; Korotaev, E. V.; Krisyuk, V. V.

doi: 10.1134/s0022476624050044pmid: N/A

An approach for predicting stability of organometallic precursors during evaporation for chemical vapor deposition is considered on the example of isostructural heteroleptic copper complexes [Cu(acac)(hfac)]2 (1) and [Cu(ki)(hfac)]2 (2). The electron density distribution in binuclear molecules of 1 and 2 is studied by the density functional theory (DFT) and X-ray photoelectron spectroscopy (XPS). It is established that the highest occupied molecular orbitals (HOMOs) and the lowest unoccupied molecular orbitals (LUMOs) of these complexes are characterized by the same composition and structure, their metal–ligand bonds and bridging Cu–O bonds in dimers have close energies, and their donor and central atoms have equal charges. It is shown that the differences between resistances of the studied heteroleptic complexes to the disproportionation upon condensed-phase heating, leading to the formation of homoleptic complexes, are determined by the kinetics of the process. We propose a mechanism of thermally activated ligand-exchange reaction as a series of rearrangements of dimeric complexes in crystals. It is shown from the calculated ΔE and ΔG values that 2 is thermally more stable than 1 due to the presence of an energy barriers it encounters at each stage of the process.[graphic not available: see fulltext]

Mishra, A. K.; Shaikh, N.; Patel, Y. K.; Mukhopadhyay, I.

doi: 10.1134/s0022476624050056pmid: N/A

The Ga-doped Li7La3Zr2O12 (LLZO) solid state electrolyte (SSE) is synthesized via the solid-state reaction. The structural study of the SSE is conducted with the help of X-ray diffraction and the Rietveld method. The SSE crystallizes in the Li6.25Ga0.15La2.90Zr2O12 phase with cubic space group number 220 and the unit cell parameter of 13.02081 Å, and the La2Zr2O7 impurity phase with cubic space group number 227 and the unit cell parameter of 10.79475 Å. The obtained lattice planes in the refinement are confirmed by TEM. The core of the Li ion migration channel is defined as the loop formed by Li32, Li1, Li2, and Li22 sites with the minimum Li⋯Li distance and occupational disorganization of Ga-doped LLZO SSE. The electron density plots of the Li6.25Ga0.15La2.90Zr2O12 phase show the maximum electron distribution inside the unit cell for lanthanum atoms. XPS confirms the presence of all the precursors, i.e., Li, La, Zr, Ga, and O in the synthesized compound. The elemental composition is confirmed by EDX. In the direct current charge-discharge behaviour of the Li symmetric cell, no voltage breakdown is observed even at 6 mA/cm2 current density and after 400 charge/discharge cycles for over 200 h.[graphic not available: see fulltext]

Mondal, B.

doi: 10.1134/s0022476624050068pmid: N/A

The title hydrazone compound containing a bicyclic heterocyclic ring is synthesized by simple stepwise condensation of 2-hydroxyacetophenone with 2-aminobenzoylhydrazide, followed by the addition of salicylaldehyde in alcohol under refluxing conditions. The compound is characterized by spectroscopic techniques, namely, FTIR, 1H NMR, mass and UV-Vis spectroscopy. The structure of this compound is determined by X-ray crystallography. The compound crystallizes in the orthorhombic crystal system with space group Pbca and a = 15.3289(9) Å, b = 14.6287(8) Å, c = 16.5451(10) Å. In the crystal structure of the compound both intra- and intermolecular hydrogen bonds are shown to exist.[graphic not available: see fulltext]

Hasanzadeh, N.

doi: 10.1134/s002247662405007xpmid: N/A

In elimination reactions, the arrangement of leaving groups plays a crucial role in facilitating the reaction. On the other hand, equatorial and axial stereoisomers of a compound have a different share of stability. The presence of a solvent plays a different role in the stability of each stereoisomer. LC-ωPBE and B3LYP methods and the Natural Bond Orbital (NBO) interpretation are used to investigate 3-chloro-8-methyl-8-azabicyclo [3.2.1] octane (1), 3-bromo-8-methyl-8-azabicyclo [3.2.1] octane (2), and 8-methyl-8-azabicyclo [3.2.1] octan-3-yl 4-methylbenzenesulfonate (3). The investigation of thermodynamic parameters shows that equatorial stereoisomers are more stable than axial ones, and by changing the gas phase to n-hexane and water, the stability of equatorial stereoisomers is increased. The stability of the equatorial stereoisomers is the result of the electrostatic model involving dipole-dipole interactions and the combined effects of hyperconjugation interactions and the total steric exchange energy (TSEE). Therefore, it can be expressed that the equatorial stereoisomers of compounds 1-3 show the superior performance in the elimination reaction of 1, 4 in the presence of a solvent, and this performance becomes more evident by changing the polarity of the solvent.[graphic not available: see fulltext]

Ozsanlı, H.; Sımsek, O.; Yılmaz, O. R.; Cıcek, C.; Agar, E.; Coruh, U.; Vazquez-Lopez, E. M.

doi: 10.1134/s0022476624050081pmid: N/A

Crystallographic features of the synthesized compound (E)-4-methoxy-2-(((2-methoxy-5-(trifluoromethyl) phenyl)imino)methyl)phenol are investigated with the Hirshfeld surface analysis and X-ray diffraction (XRD). The stability of the crystal packing primarily stems from N–H⋯O and C–H⋯O bonding interactions, further fortified by offset π⋯π stacking interactions. To delve into the supramolecular arrangement, the Hirshfeld surface analysis is conducted, shedding light on the intricacies of the crystal packing. The structure of the synthesized compound is determined through the single crystal XRD analysis, revealing its crystallization within the triclinic crystal system, space group \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$P\bar{1}$$\end{document}. The supramolecular assembly is explored by the Hirshfeld surface analysis, and the supramolecular geometric features of the title compound involve the compact arrangement of title molecules with each other. The dispersion energy properties are examined through studies on the interaction energy and energy frameworks.[graphic not available: see fulltext]

Dua, A.; Titi, H. M.; Sharma, H. K.; Roy, S.

doi: 10.1134/s0022476624050093pmid: N/A

A new cocrystal solvate possessing 2,7,14-trihydroxytriptycene (THT) and 4,4′-bipyridine (bpy) is grown from a MeOH solution by solvent evaporation to form THT·0.5bpy·MeOH·H2O (1). The crystal structure of 1 is determined by single crystal X-ray diffraction in the monoclinic space group C2/c. In new cocrystal solvate 1, the asymmetric unit consists of one unit of THT, a half unit of disordered bpy, one unit of a water molecule, and one MeOH molecule. A 2D supramolecular architecture is observed in 1, which links THT, bpy and solvent water molecules via classical O–H⋯N and O–H⋯O hydrogen bonds. The MeOH and water molecules entrapped in 1 form stabilizing hydrogen bonds with the surrounding “trimeric cocrystals”. Furthermore, we investigate whether these hydrogen bonds stabilize the crystal packing or not. The calculations are carried out using Hydrogen Bond Statistics and Full Interaction Maps packages, and the results exhibit the common bonding behaviour in terms of bond distances and strength.[graphic not available: see fulltext]

Fedorov, P. P.; Volkov, S. V.; Vaitieva, Y. A.; Aleksandrov, A. A.; Kuznetsov, S. V.; Konyushkin, V. A.

doi: 10.1134/s002247662405010xpmid: N/A

Optically transparent single-crystal blocks are prepared by the fusion of a barium fluoride charge with yttrium and erbium fluorides using sodium fluoride as a flux. The crystal structures were solved and composition of the following phases were determined: Na0.75Ba1.26Er1.99F9.24 (cubic crystal system, \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$Fm\bar{3}m$$\end{document} space group, a = 11.4192(4) Å), Na0.25BaY2.75F10.5 (cubic crystal system, \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$Fm\bar{3}m$$\end{document} space group, a = 11.4350(19) Å), Na0.05Ba0.9Y1.05F5 (orthorhombic crystal system, Cmmm space group, a = 5.7205(5) Å, b = 17.2348(11) Å, c = 5.7648 (4) Å).[graphic not available: see fulltext]