Search Results (43)

Four benzyltrimethylammonium (BTMA) salts were successfully prepared: bis(benzyltrimethylammonium) hexachloroplatinate (1), benzyltrimethylammonium tetrachloroaurate (2), bis(benzyltrimethylammonium) tetrachlorocuprate (3), and bis(benzyltrimethylammonium) tetrabromocuprate (4) from benzyltrimethylammonium hydroxide (Triton B). Their crystal structures were determined by single-crystal X-ray diffraction, and the supramolecular architectures were characterized hierarchically. Extended Hirshfeld surface analysis, including enrichment ratio calculations, was performed to evaluate intermolecular interactions. Nonclassical hydrogen bonds, such as C–H^…Cl(Br), involving the anions, contribute to the formation of self-assembled architectures. Additional stabilization arises from π^…π and Cu–Br^…π interactions, particularly in crystals 2 and 4, respectively. Hirshfeld surface analysis showed that H^…H and C^…H/H^…C interactions are the dominant contributors in all crystals. According to enrichment ratio calculations, C^…H/H^…C interactions in 1, 3, and 4; Cl^…H/H^…Cl in 1 and 3; Cu^…H/H^…Cu in 3 and 4; and Br^…H/H^…Br and Br^…C/C^…Br in 4 are statistically favored in the crystal packing. Halogen bonding Cl^…Cl was observed in 1 but does not significantly influence packing. Energy framework calculations indicated that dispersive interactions are favorable in the analyzed crystals. A library of H-bonding supramolecular patterns, including interchangeable synthons, is provided and may guide the rational design of new derivatives with controllable features. Finally, the topology of intermolecular connections and the electronic structure of the benzyltrimethylammonium cation, investigated by quantum-chemical calculations, provide insights into its reactivity. Full article

The crystal structures and vibrational spectra of 5-chloro-7-azaindole (5Cl7AI), 4,5-dichloro-7-azaindole (4,5Cl7AI), and 5-hydroxy-7-azaindole (5OH7AI) were investigated to elucidate how ring substituents modulate intermolecular hydrogen bonding and molecular packing in the solid state. Density functional theory (DFT) calculations were employed to support the interpretation of the spectroscopic data, while Hirshfeld surface analysis provided additional insight into intermolecular contacts. Single-crystal X-ray diffraction revealed that the halogenated derivatives form nearly linear N–H···N hydrogen-bonded dimers or layered arrangements, whereas 5OH7AI adopts a three-dimensional network stabilized by N–H···O and O–H···N interactions. FT-IR and FT-Raman spectra showed that variations in hydrogen-bond topology strongly affect the N–H and O–H stretching regions: the halogenated derivatives exhibit broad, red-shifted bands (3300–2500 cm⁻¹) characteristic of N–H···N hydrogen bonds, while 5OH7AI displays smaller red shifts of the N–H stretching bands accompanied by some additional features from O–H stretching vibrations. DFT calculations at the B3LYP-D3 and ωB97X-D levels reproduced the experimental geometries and vibrational spectra very well, providing detailed insight into the relationship between hydrogen-bond linearity, network dimensionality, and vibrational behavior. Full article

The substituent effects on crystal stacking topology and stability of the 5,5-dinitro-2H,2H-3,3-bi-1,2,4-triazole (DNBT) and its three energetic cocrystals with 1,3,5-trinitrobenzene (TNB), 2,4,6-trinitrotoluene (TNT), and picric acid (PA) were systematically investigated through combined density functional theory (DFT) calculations and classical molecular dynamics (MD) simulations. The interaction mechanism and detonation performance of the three energetic cocrystals were implemented to the electrostatic potential (ESP), Hirshfeld surface analysis, radial distribution function (RDF), binding energy, and detonation parameters. In contrast to N-H⋯O interactions in DNBT, three cocrystals exhibited more distinctly weak C-H⋯O intermolecular hydrogen bonds and NO₂-π stacking interactions to stabilize the lattice. Notably, the highest binding energy of PA/DNBT shows the largest stability and lowest impact sensitivity is related to the more intermolecular interactions. Although the introduction of substituents slightly affects the crystal density of DNBT crystals, it significantly reduces the impact sensitivity. Moreover, the balanced detonation performance and impact sensitivity of DNBT-based cocrystals make it a candidate to expand the applications of DNBT crystals. These findings contribute to a broadened understanding of construction and design strategies for the energy release mechanisms of energetic compounds with the azoles ring family. Full article

This article discloses the synthesis of four new positional isomeric zwitterionic ligands exhibiting semi-flexible and flexible characteristics—n-pyridinium-1,2,3-triazole-4-carboxy-5-Acetate (n-PTCA), and n-methylpyridinium-1,2,3-triazole-4-carboxy-5-Acetate (n-MPTCA; where n = 3, 4)—which were derived from an aqueous solution of the corresponding sodium salts in an acidic medium (HCl). These compounds are successfully synthesized and characterized with FT-IR and multinuclear NMR spectroscopy; likewise, proper single crystals are obtained for each compound. All compounds adopt zwitterionic forms in the solid state, which are stabilized via intermolecular proton transfer processes involving HCl and solvent molecules. A single-crystal X-ray analysis revealed how positional isomerism and molecular flexibility influence the supramolecular topology. Specifically, 3-PTCA and 4-PTCA exhibit isomorphic hydrogen bond networks, while 3-MPTCA and 4-MPTCA display distinct packing motifs, attributed to the presence of a methylene spacer between the pyridinium and triazole rings. The Hirshfeld surface analysis quantitatively confirmed the dominance of O···H/H···O and N···H/H···N interactions in the solid-state architecture. These strong hydrogen-bonding networks are indicative of the potential proton-conductive behavior in the crystalline state, positioning these compounds as promising candidates for applications in proton-conducting materials. The structural insights gained underscore the pivotal role of molecular topology in tailoring crystal packing, with implications for the rational design of zwitterionic ligands in functional materials, including MOFs and coordination polymers. The calculated HOMO-LUMO energy gaps reveal a significant electronic variability among the ligands, influenced primarily by the positional isomerism and structural flexibility introduced by the methylene spacer. Full article

Three diaryliodonium dicyanoargentates(I), [MesIAr][Ag(CN)₂] (Ar = Ph 1, Mes 2, 4-MeC₆H₄ 3; Mes = 2,4,6-Me₃C₆H₂), were prepared by anion metathesis. The X-ray structural analyses for these crystals revealed C–I^III∙∙∙N≡C halogen bonds (abbreviated as XB) between I atoms of diaryliodonium cations and N atoms of cyano groups, which provide different supramolecular organization. The noncovalent nature of these interactions was studied by density functional theory (DFT) calculations and topological analysis of the electron density distribution in the framework of the quantum theory of atoms in molecules (QTAIM) at the PBE-D3/jorge-DZP-DKH level of theory both in gas phase and crystal models. The philicities of partners in these contacts were confirmed by electron localization function (ELF) projections, electron density/electrostatic potential (ED/ESP) profiles, and Hirshfeld surfaces analysis. An analysis of the available crystallographic data from the literature allows us to find other examples of σ-hole interactions including the dicyanoargentate(I) anion, and the C–X∙∙∙N≡C (X = Br, I, Te) bonding were also confirmed theoretically. Full article

The crystal structures of naphthalene dicarboxamides, namely 1,4-naphthalene dicarboxamide (1,4-NDA), 2,6-naphthalene dicarboxamide (2,6-NDA), and 2,7-naphthalene dicarboxamide (2,7-NDA), are presented for the first time, along with an analysis of their supramolecular organization. The compounds, obtained in single-crystalline form via solvothermal crystallization from methanol, are stable in air to near 350 °C and have melting points above 300 °C. In their densely packed structures (ρ = 1.43–1.47 cm³g⁻¹) the combination of ${\mathrm{C}}_1^1$ (4) chains and ${\mathrm{R}}_2^2$(8) rings generates one-dimensional hydrogen-bonded ladders, with an additional ${\mathrm{R}}_4^2$(8) pattern. The amide groups and the naphthalene rings form dihedral angles between 22° and 40°. Neighboring H-bond ladders run parallel in 1,4-NDA and 2,6-NDA and are connected by means of the naphthalenedyil cores so that two-dimensional (2D) H-bonded sheets are obtained. Except for a weak intra-sheet π–π stacking in 1,4-NDA, there are no π–π stacking and C–H⋯π interactions. The ${\mathrm{R}}_2^2$(8) rings act as four-connected nodes, leading to the formation of two-dimensional H-bonded planar sheets with sql topology for the nearly linear dicarboxamides 1,4-NDA and 2,6-NDA and cds topology for the angular 2,7-NDA. Hirshfeld surface analysis and NCI plots provide additional insight into the H-bonding interactions. Full article

The crystal structure and topology analyses of a new bromo-Mn(II) complex with 2,4-bis(3,5dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (MBPT) were reported. Its structure was confirmed using single-crystal X-ray diffraction to create the formula [Mn(MBPT)Br(H₂O)₂]ClO₄. Its crystal system was monoclinic and its space group was p2₁. The Mn(II) was coordinated with MBPT as a NNN-pincer ligand, with one bromide ion in the equatorial plane. The two axial terminals were occupied by two trans water molecules. H…H, N…H, Br…H, C…H and O…H were the predominant intermolecular contacts, while Br…H, O…H and C…O were the significant contacts based on Hirshfeld analysis. Moreover, anion–ᴨ interaction was found between C(s-triazine) and O(perchlorate). This complex had better antioxidant activity than the free ligand (MBPT). In addition, the cytotoxicity of the [Mn(MBPT)Br(H₂O)₂]ClO₄ complex showed better results against HepG-2 and MCF-7 cells, recording IC₅₀ values of 31.11 ± 2.04 and 50.05 ± 2.16 µM, respectively, compared to the free ligand (IC₅₀ = 671.44 ± 21.41 and 1113.55 ± 29.77 µM). In comparison to cis-platin as a reference drug, the IC₅₀ values were 63 and 80 μM, respectively, which indicated the promising anticancer activity of the studied compound against both cell lines. In terms of the safety of normal cells, the Mn(II) complex recorded a high IC₅₀ value of 359.10 ± 8.72 µM against the WI-38 non-cancerous cell line. The complex showed better activity towards Staphylococcus aureus, Bacillus subtilis, and Proteus vulgaris relative to the free MBPT, but had low to moderate activity compared to Gentamycin as an antibacterial positive control. Full article

Thiadiazole (THD) derivatives are famous for their exceptional chemical properties and versatile biological activities. In this work, we report computational investigations of the structure, reactivity, and binding affinity of three 1,3,4-THD derivatives (THDs) toward the SARS-CoV-2 main protease (Mpro). Hirshfeld surface (HS) analyses are carried out in conjunction with topological calculations in the context of the quantum theory of atoms in molecules (QTAIM) and reduced density gradient (RDG) to unravel the nature and magnitude of noncovalent interactions that contribute to maintaining these THDs. The three approaches consistently indicate that the titled THDs are mainly stabilized by weak intramolecular H…H, C-H…π, C-H…N, and N-H..H interactions in their monomeric forms, while their dimers also exhibit intermolecular π…π stacking and T-shaped contacts. In addition, Hirshfeld atomic charges, frontier molecular orbitals (FMOs), Fukui functions, and molecular electrostatic potential (MEP) reveal that the pyrrolic H atom (ring F) and the imidazole N atom (ring E) are the preferred binding sites for nucleophilic and electrophilic attacks, respectively. Finally, docking and molecular dynamics simulations demonstrate the remarkable binding profile of THDs toward the Mpro, which can be related to potential inhibitory activity. Full article

Metal–organic frameworks (MOFs) are peculiar multimodal materials that find photocatalytic applications for the decomposition of lethal molecules present in the wastewater. In this investigation, two new d¹⁰-configuration-based MOFs, [Zn₂(L)(H₂O)(bbi)] (1) and [Cd₂(L)(bbi)] (2) (5,5-(1,4-phenylenebis(methyleneoxy)diisophthalic acid (H₂L) and 1,1′-(1,4-butanediyl)bis(imidazole) (bbi)), have been synthesized and characterized. The MOF 1 displayed a (4,6)-connected (3.4³.5²)(3².4⁴.5².6⁶.7) network topology, while 2 had a (3,10)-connected network with a Schläfli symbol of (4¹⁰.5¹¹.6²².7²)(4³)₂. These MOFs have been employed as photocatalysts to photodegrade nitrophenolic compounds, especially p-nitrophenol (PNP). The photocatalysis studies reveal that 1 displayed relatively better photocatalytic performance than 2. Further, the photocatalytic efficacy of 1 has been assessed by altering the initial PNP concentration and photocatalyst dosage, which suggest that at 80 ppm PNP concentration and at its 50 mg concentration the MOF 1 can photo-decompose around 90.01% of PNP in 50 min. Further, radical scavenging experiments reveal that holes present over 1 and ·OH radicals collectively catalyze the photodecomposition of PNP. In addition, utilizing density of states (DOS) calculations and Hirshfeld surface analyses, a plausible photocatalysis mechanism for nitrophenol degradation has been postulated. Full article

The hydrazones 3a–c, were synthesized from the reaction of indole-3-carbaldehyde and nicotinic acid hydrazide, isonicotinic acid hydrazide, and benzoic acid hydrazide, respectively. Their structures were confirmed using FTIR, ¹HNMR, and ¹³CNMR spectroscopic techniques. Exclusively, hydrazones 3b and 3c were confirmed using single crystal X-ray crystallography to exist in the Eanti form. With the aid of DFT calculations, the most stable configuration of the hydrazones 3a–c in gas phase and in nonpolar solvents (CCl₄ and cyclohexane) is the ESyn form. Interestingly, the DFT calculations indicated the extrastability of the EAnti in polar aprotic (DMSO) and polar protic (ethanol) solvents. Hirshfeld topology analysis revealed the importance of the N…H, O…H, H…C, and π…π intermolecular interactions in the molecular packing of the studied systems. Distribution of the atomic charges for the hydrazones 3a–c was presented. The hydrazones 3a–c showed a polar character where 3b has the highest polarity of 5.7234 Debye compared to the 3a (4.0533 Debye) and 3c (5.3099 Debye). Regarding the anti-toxoplasma activity, all the detected results verified that 3c had a powerful activity against chronic toxoplasma infection. Compound 3c showed a considerable significant reduction percent of cyst burden in brain homogenates of toxoplasma infected mice representing 49%. Full article

The two group IIB complexes [Cd(DMPT)Cl₂] (6) and [Zn(DMPT)Cl₂] (7) of the tridentate ligand (DMPT), 2,4-bis(morpholin-4-yl)-6-[(E)-2-[1-(pyridin-2-yl) ethylidene]hydrazin-1-yl]-1,3,5-triazine were synthesized, and their structural aspects were elucidated with the aid of X-ray crystallography. Both complexes crystallized in the monoclinic crystal system, with P2₁/n as a space group. The unit cell parameters for 6 are a = 14.1563(9) Å, b = 9.4389(6) Å, c = 16.5381(11) Å and β = 91.589(5)° while the respective values for 7 are 11.3735(14), 13.8707(13), 14.9956(16), and 111.646(2)°. The unit cell volume is slightly less (2198.9(4) ų) in complex 7 compared to complex 6 (2209.0(2) ų). Both complexes have a penta-coordination environment around the metal ion, where the DMPT ligand acts as a neutral tridentate NNN-chelate via the pyridine, hydrazone, and one of the s-triazine N-atoms. The penta-coordination environment of the Cd(II) in complex 6 is close to a square pyramidal configuration with some distortion. On the other hand, the ZnN₃Cl₂ coordination environment is highly distorted and located intermediately between the trigonal bipyramidal and square pyramids. Supramolecular structure analysis of 6 with the aid of Hirshfeld calculations indicated the importance of the Cl…H, O…H, and C…H interactions. Their percentages were calculated to be 20.9, 9.1, and 8.7%, respectively. For 7, the Cl…H, O…H, C…H, and N…H contacts are the most important. Their percentages are 20.3, 9.0, 7.0, and 8.4%, respectively. In both complexes, the major intermolecular interaction is the hydrogen–hydrogen interactions which contributed 45.5 and 46.6%, respectively. Full article

Since chemistry, materials science, and crystallography deal with three-dimensional structures, they use mathematics such as geometry and symmetry. In recent years, the application of topology and mathematics to material design has yielded remarkable results. It can also be seen that differential geometry has been applied to various fields of chemistry for a relatively long time. There is also the possibility of using new mathematics, such as the crystal structure database, which represents big data, for computational chemistry (Hirshfeld surface analysis). On the other hand, group theory (space group and point group) is useful for crystal structures, including determining their electronic properties and the symmetries of molecules with relatively high symmetry. However, these strengths are not exhibited in the low-symmetry molecules that are actually handled. A new use of mathematics for chemical research is required that is suitable for the age when computational chemistry and artificial intelligence can be used. Full article

The stoichiometric ratio 2:1 mix of 1-phenylpiperazine and oxalic acid dihydrate followed by slow evaporation results in a new material, bis(4-phenylpiperazin-1-ium) oxalate dihydrate, with the general chemical formula (C₁₀H₁₅N₂)₂(C₂O₄).2H₂O, indicated by PPOXH. The title compound’s asymmetric unit and three-dimensional network have been determined by single crystal X-ray diffraction. Intermolecular O-H…O, N-H…O and C-H…O hydrogen bonding assist in maintaining and stabilization of the crystal structure of this new compound. Hirshfeld surface analysis and two-dimensional fingerprints have been performed to quantify the non-covalent interactions in the PPOXH structure. The vibrational modes of the different characteristic groups of the title chemical were identified using infrared spectrum analysis. The thermal characterization of this product was studied by a coupled TG/DTA analysis. The ultraviolet-visible absorption spectrum has been used to study the optical properties and the energy gap of this compound. DFT calculations were employed to evaluate the composition and properties of PPOXH. The analysis of HOMO-LUMO frontier orbitals analysis allows us to understand the chemical reactivity of this supramolecular compound and to determine the electrophilic and nucleophilic sites responsible for electron transfer. Topological analysis (AIM), reduced density gradient (RDG), molecular electrostatic potential surface (MEPS) and Mulliken population were analyzed to evaluate the types of non-covalent interactions, localization of electrons in space, atomic charges and molecular polarity in depth. Full article

Single crystals of a new organic–inorganic hybrid compound (C₃H₇N₆)₂[ZnCl₄]·H₂O was synthesized and characterized by X-ray diffraction at room temperature, FT-IR and FT-Raman spectroscopies, optical absorption and photoluminescence behavior. The title compound belongs to the triclinic space group P$\overline{1},$ and in the crystal structure, the inorganic layers are built from tetrachloridozincate anions [ZnCl₄]²⁻ and free water molecules, linked together by O–H···Cl hydrogen bonds and halogen···halogen interactions. In addition, Hirshfeld surfaces and 2D fingerprint plots estimate the weak intermolecular interactions accountable for the generation of crystal packing. The optimized geometry, vibrational frequencies and various thermodynamic parameters of the title compound calculated using density functional theory (DFT) methods are in agreement with the experimental values. The theoretical calculations were performed using the DFT method at WB97XD/Lanl2dz basis set levels and we discussed topological analysis of atoms in molecules (AIM) at the BCP point. A detailed interpretation of the IR and Raman spectra were reported. Additionally, the simulated spectrum satisfactorily coincided with the experimental UV-Visible spectrum. A wide band gap exceeding 4 eV of the synthesized compound was recorded. The photoluminescence (PL) was characterized through two bands successively at 453 and 477 nm. Ultimately, antimicrobial activity and enzymatic inhibition assays of the complex were also investigated through microbial strains, agar diffusion method, minimum inhibitory concentration (MIC) determination, lipase and phospholipase A₂ inhibition. Full article

In this paper, a novel hybrid material, entitled histaminium bis(trioxonitrate), with the general chemical formula (C₅H₁₁N₃)(NO₃)₂, denoted by HTN was presented. Single-crystal X-ray diffraction was used to determine the structural characteristics of this compound after it was made using a slow evaporation method at room temperature. This compound was elaborated and crystallized to the monoclinic system with space group P2₁/c, and the lattice parameters obtained were: a = 10.4807 (16)Å, b = 11.8747 (15)Å, c = 16.194 (2)Å, β = 95.095 (6)°, V = 2007.4 (5)ų and Z = 8. The title compound’s atomic structure couldbe modeled as a three-dimensional network. Organic cations and nitrate anions were connected via N–H...O and C–H...O hydrogen bonds in the HTN structure. The intermolecular interactions responsible for the formation of crystal packing were evaluated using Hirshfeld surfaces and two-dimensional fingerprint plots. The compound’s infrared spectrum, which ranged from 4000 to 400 cm⁻¹, confirmed the presence of the principal bands attributed to the internal modes of the organic cation and nitrate anions. Additionally, spectrofluorimetry and the ultraviolet–visible spectrum was used to investigate this compound. DFT calculations were used to evaluate the composition and properties of HTN. The energy gap, chemical reactivity and crystal stability of HTN were quantified by performing HOMO-LUMO frontier orbitals analysis. Topological analysis (AIM), Reduced Density Gradient (RDG), molecular electrostatic potential surface (MEPS) and Mulliken population were processed to determine the types of non-covalent interactions, atomic charges and molecular polarity in detail. Full article