Two dicyanamido- and azido-bridged Cu(II) coordination polymers with N-(2-pyridylmethyl)-L-alaninato as chiral ligand: Synthesis, structures, luminescence properties, and Hirshfeld surface analysis

Two chiral coordination compounds based on valine derivatives: Synthesis, characterization, Hirshfeld surface analysis, and fluorescent chiral recognition properties

Synthesis, optical and photovoltaic properties, and Hirshfeld surface analysis of hybrid organic-inorganic 2C6CoCl4

The reaction of 1,1-bis-(carboxymethylthio)-1-phenylethane with piperidine was conducted in an acetone solution at a molar ratio of the initial components of 1:2. As a result, a new compound was obtained: piperidinium-1,1-bis-(carboxymethylthio)-1-phenylethane, characterized by FT-IR. The crystal structure of the synthesized compound is structurally elucidated via single crystal XRD technique, indicating that a H-atom is transferred from half of the piperidinium-1,1-bis-(carboxymethylthio)-1-phenylethane part to the piperidine ring and the structure is a salt in nature. N–H ⋯ O and C–H ⋯ O bondings contribute to the stability and enforcement of crystal packing; further assessment is supported via Hirshfeld surface analysis, considering interatomic contacts. We employed density functional theory (DFT)-based computations along with molecular dynamics (MD) simulations in a systematic manner, aiming for the investigation of the stabilizing interactions and electronic characteristics of the molecular ionic compound. The structural framework is notably stabilized by dual N–H···O hydrogen bonding, originating from piperidine rings positioned on either side of the central fragment. Electronic structure analysis revealed intermolecular charge transfer characteristics through HOMO–LUMO orbital distributions, complemented by TD-DFT studies of excited state behavior. Furthermore, ab initio MD simulations at 300 K conclusively demonstrated the ionic compound's robust kinetic and dynamic stability.

Abstract Three novel phosphor/thiophosphor-amides, [(5-CH 3 )- 2 Py-NH] 2 [C 6 H 11 (CH 3 )N]P(X) (X = O ( 1 ) and S ( 2 )) and [(5-CH 3 )- 2 Py-NH]P(O)[OCH 2 C(CH 3 ) 2 CH 2 O] ( 3 ), were synthesized and characterized by FT-IR and 1 H/ 13 C/ 31 P-NMR spectroscopy. The structures of 1 and 3 were determined by using single-crystal X-ray diffraction (SC-XRD) crystallography which reveals both compounds to crystallize in monoclinic space groups ( P 2 1 / c and P 2 1 / n , respectively). A crystal packing analysis shows that neighbouring molecules are connected together via N–H⋯O═P hydrogen bonds forming one-dimensional chains. A Hirshfeld surface analysis indicates that crystal packing is dominated by H⋯H, H⋯O/O⋯H, H⋯C/C⋯H, and H⋯N/N⋯H contacts, with O⋯H/H⋯O interactions including the classical N–H⋯O═P hydrogen bonds being particularly favored. Phosphor/thiophosphor-amide derivatives are emerging as promising scaffolds for targeting key enzymes of acetylcholinesterase (1EEA, 5FPP) and urease (2UBP, 4GY7). Molecular docking revealed favorable binding affinities (up to −10.3 kcal/mol for 1 with 1EEA), with compounds 1 and 2 generally exhibiting stronger predicted interactions than compound 3 . Key stabilizing interactions involve phosphoryl/thiophosphoryl groups and pyridine rings. Redocking of co-crystallized ligands with RMSD assessment confirmed the reliability of the docking protocol. While these results do not provide definitive evidence of inhibitory potency, they support further computational refinement and experimental evaluation, highlighting the potential of these derivatives as enzyme-interacting agents with biomedical relevance.

This study reports, for the first time, the bio-synthesis of Magnesium Oxide Nanoparticles using Piper longum leaf extract. A sustainable approach was introduced for the fabrication of pure MgO Nanoparticles from the extract of Piper longum leaves through the surfactant Cetyltri methyl ammonium bromide mediated co-precipitation technique. Bioactive phyto chemical compounds in the extract served as a reducing and stabilizing agent, while they act as a surfactant to control the shape and dispersion of nanoparticles. X-ray diffraction confirmed the formation of cubic-phase crystalline magnesium oxide nanoparticles with an average crystallite size of 24.78nm. The Fourier transform infrared spectra indicated characteristic phyto chemical capping along with Mg-O bonding functional groups stretching around 500cm⁻¹. Scanning electron microscopy images reveals densely packed porous surface with agglomerated nano clusters, and energy dispersive X-ray spectroscopy confirmed the elemental composition of synthesized nanoparticles and their purity. Hirshfeld surface analysis was performed to analyse the intermolecular interactions as well as surface characteristics of MgO nanoparticles at an atomic level, with emphasis on the significance of strong ionic and hydrogen bonding to their stability. Antibacterial activity was investigated against Escherichia coli and Staphylococcus aureus using the agar well disc diffusion method, showing concentration-dependent with a maximum zone of 14.1mm observed against Escherichia coli. The synthesised nanoparticles showed great antioxidant activity and these findings report the feasibility of Piper longum-mediated green synthesis of MgO nanoparticles for potential biomedical applications.

In the title salt, (C 2 H 4 N 3 S) 2 [MnCl 2 (C 3 H 2 O 4 )(H 2 O) 2 ], the central Mn II atom of the complex anion adopts a distorted octahedral coordination environment, defined by two aqua, two chlorido, and one bidentate malonato ligands. The anion is charge balanced by two thiadiazole moieties protonated at one of the heterocyclic N atoms. In the crystal, the cations and anions engage in extensive hydrogen-bonding interactions and short S...Cl contacts; additional π–π stacking interactions are present between adjacent cations. Hirshfeld surface analysis was used to quantify the intermolecular interactions of the complex anion, revealing that H...O, H...Cl, and H...H interactions contribute most to the crystal packing.

ABSTRACTThe formation of salts remains a highly sought‐after yet unpredictable strategy for resolving chiral drugs. Using a drug–drug approach, we have investigated the crystallization behavior of Mefloquine (Mf), a racemic antimalarial drug, in combination with enantiopure (S)‐ibuprofen and (S)‐ketoprofen, as well as their racemic forms. Double salts and racemates have been obtained and characterized by single‐crystal and powder X‐ray diffraction, Hirshfeld surface analysis, thermal analysis (DSC and TGA), and solubility measurements. Structural analysis reveals that the formation of double salts often follows a pattern similar to the packing and supramolecular motifs found in the corresponding racemates. For the ketoprofen systems, the double salt and racemate have been found to be isostructural and isomorphic, whereas the ibuprofen systems display different architectures despite similar unit cells. Both double salts exhibited thermal stability and solubility profiles comparable to their racemic counterparts. On the other hand, the racemate with ketoprofen and the double salt with ibuprofen are the most soluble structures, suggesting that they are more stable systems than their counterparts. These findings support the view that double salt formation in such systems results from structural mimicry of racemates, emphasizing the challenges of predictable enantiomeric resolution and the importance of understanding structure–property relationships in chiral crystallization.

The title coordination complex, bis(μ-pyridin-1-ium-3-carboxylato-κ 2 O : O ′)bis[diaquabis(nitrato-κ 2 O , O ′)calcium(II)], [Ca 2 (C 6 H 5 NO 2 ) 2 (NO 3 ) 4 (H 2 O) 4 ], was prepared from calcium nitrate and nicotinic acid in a water–ethanol solvent mixture. The asymmetric unit contains a half molecule of the complex, with the calcium atom exhibiting a coordination number of eight, forming a distorted dodecahedral geometry with a mixed-ligand environment. The μ 2 -O, O ′ bridging zwitterionic nicotinic acid molecules generate a centrosymmetric dinuclear complex. The extended structure features N—H...O, O—H...O and C—H...O hydrogen bonds, which generate a three-dimensional network. Hirshfeld surface and two-dimensional fingerprint plot analyses were performed to quantify and visualize the intermolecular interactions contributing to the overall cohesion of the structure.

Three novel platinum (II) mixed-ligand complexes were yielded by reacting a coumarin derivative (CoumH) and 1,1'-bis(diphenylphosphino)ferrocene (Dppf) with Pt(II)salt. This reaction was carried out by using a two-step method in neutral and basic media. To identify the resulting complexes, various spectroscopic techniques were used, including single-crystal diffraction, FTIR, UV-Vis, NMR spectroscopy, and CHN analysis. The NMR data of the complexes prove that the coumarin derivative behaves differently depending on the medium, whether it is basic or neutral; in neutral conditions, the coumarin derivative coordinates as a monodentate ligand through its keto oxygen. In basic media, the deprotonated ligand forms a bidentate coordination with the oxygen atom and anionic oxygen. All Pt(II) complexes show square planar geometry and have the following chemical formula: [Pt(Dppf)Cl₂]. H₂O (1), [Pt(CoumH)₂(Dppf)]Cl₂ (2), and [Pt(Coum)(Dppf)]Cl (3). Pt(II) complexes were evaluated against two types of bacteria, Escherichia coli and Staphylococcus aureus. [Pt(Coum)(Dppf)]Cl complex exhibited excellent antibacterial activity against both bacteria. Additionally, the cytotoxicity results revealed that complexes [Pt(CoumH)₂(Dppf)]Cl₂, and [Pt(Coum)(Dppf)]Cl have potential antitumor activity and inhibited 69% and 63% of cancer cells, respectively. Stability and molecular reactivity of the complexes have been established through the utilization of density functional theory (DFT), Hirshfeld surface, and non-covalent interaction analysis. KEY WORDS: Platinum(II) Complexes, Coumarin derivatives, Dppf ligand, Anticancer, DFT study Bull. Chem. Soc. Ethiop. 2026, 40(4), 907-927. DOI: https://dx.doi.org/10.4314/bcse.v40i4.13

Sulfaguanidine-based schiff bases, synthesis, crystal structure, FT-IR, hirshfeld surface analysis, and concise computational study

We report the single-crystal X-ray diffraction structures of the azobenzene-bridged aza-18-crown-6 cryptand 7,16-[3,3′-(diazene-1,2-diyl)bis(1,3-phenylenecarbonyl)]-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane, C 26 H 32 N 4 O 6 , 1 , and its sodium complex poly[[{μ-7,16-[3,3′-(diazene-1,2-diyl)bis(1,3-phenylenecarbonyl)]-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane}bis{tetrakis[3,5-bis(trifluoromethyl)phenyl]borato}disodium] benzene disolvate], {[Na 2 (C 32 H 12 F 24 B) 2 (C 26 H 32 N 4 O 6 )]·2C 6 H 6 } n . The free ligand 1 crystallizes in space group P 2 1 / n and adopts an elongated strain-distorted crown conformation with a slightly twisted azobenzene unit. In contrast, 2 [obtained with sodium tetrakis-3,5-bis(trifluoromethyl)phenyl borate (NaBArF)] crystallizes in space group P 1 and features multiple Na + centers that assemble into a three-dimensional network in the solid state. Hirshfeld surface analysis was used to provide a complementary, quantitative description of the dominant intermolecular contacts governing the crystal packing.

The quantum calculation of 2,5-Furandicarboxylic acid (FDA) structure using the density functional theory was reported in this paper. Then, the physic-chemical characteristics as well as the biological properties of the title compound were determined. The geometrical structure was optimized using B3LYP/6-311++G(d,p) level of theory. In this context, the structural parameters with and without dispersion correction were calculated and compared with x-ray data showing good agreement. Besides, the FTIR spectrum was simulated in the range 0-4000 cm -1 and compared with the experimental one. The strongest electrophilic (H14 and H15) and nucleophilic (O4 and O5) sites were identified using MEP analysis. The weak gap energy value (-4.98 eV) demonstrates the high chemical reactivity and the easier electronic passage. In addition, the electrophile index (5.07 eV) indicates that the investigated molecule was a good electrophile. Furthermore, the topological study shows the establishment of hydrogen bonding interactions (O-H…O) among the carboxylic acids. These bonds were associated with a -27.6 kcal/mol interaction energy value. The non covalent C-H…O, O-H…O and O-H…C interactions responsible for the crystal stability and the 𝜋⋯𝜋 stacking interaction were discovered using Hirshfeld surface analysis. As a final point, docking analysis and ADME properties were presented to explore the pharmaceutical features of the title compound. The finding results show that the FDA presents good results with 1DQN, 1VZV, 4NZK, 9H9V and 2QGO demonstrating their ability to be an anti-viral, anti-inflammatory and anti-microbial compound.

This study presents a combined theoretical and experimental investigation into the structural, electronic, and vibrational properties of Gd2MoO6. To gain deeper insight into its chemical composition, first-principles calculations were employed, emphasizing energy band analysis. The conduction band minimum is positioned at the high-symmetry Γ-point, while the valence band maximum appears between the Z and Γ-points. These results indicate that Gd2MoO6 is a semiconductor exhibiting an indirect band gap of approximately 1.92 eV. Furthermore, lattice dynamics were examined using density functional theory (DFT) to interpret the experimental Raman and infrared spectra. Hirshfeld surface and structural analyses reveal that Gd2MoO6 exhibits a hybrid ionic-covalent framework governed by dominant Gd-O/Gd-O and Mo-O/O-Mo bonds. Additionally, pressure-dependent Raman spectroscopy was carried out to explore structural modifications resulting from pressure variations. Based on the spectral changes, two phases' transitions were identified at approximately 3.1-3.3 GPa and 9.5-10 GPa, potentially linked to increased disorder of octahedra induced by pressure effects. The principal component analysis and hierarchical cluster analysis identified two phase transitions at near pressure range of 3.1-3.3 GPa and 9.5-10. GPa, which are in agreement with the pressure-dependent Raman studies.

The title compound, C 21 H 15 N 3 O 2 , contains a nitroaniline ring and an anthracene ring system bridged over the methylene amino group. The anthracene ring system is essentially planar with an r.m.s. deviation of 0.03 (2) Å and it is oriented at a dihedral angle of 79.70 (5)° with respect to nitroaniline ring. There is an intramolecular N—H...N hydrogen bond between N atoms of nitroaniline ring and amino group. In the crystal, N—H—O hydrogen bonds link the molecules into infinite chains along the b -axis direction. π–π stacking interactions between the nitroaniline rings of adjacent molecules with centroid-to-centroid distance of 3.7682 (2) Å and C—H...π(ring) interactions may help to consolidate the three-dimensional architecture. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H...H (35.5%), H...C/C...H (33.7%) and H...O/O...H (18.3%) interactions.

During the synthesis of the (oxalato)[5,10,15,20-tetrakis(4-chlorophenyl)porphyrinato]magnesium(II) ([Mg(TClPP)(ox)]) complex [TClPP = 5,10,15,20-tetrakis(4-chlorophenyl)porphyrinate and ox = oxalate], the title compound, [Mg(C 44 H 24 ClMgN 4 O 2 )(H 2 O) 2 ] ([Mg(TClPP)(H 2 O) 2 ]), was obtained as a by-product. The diaqua–Mg II porphyrin complex crystallizes in the I 4/ m space group. In the asymmetric unit, except for two carbon atoms of the phenyl ring, all atoms lie on special positions. In the crystal, the [Mg(TClPP)(H 2 O) 2 ] molecules form layers parallel to the a axis. The crystal packing features C—H...π interactions involving the pyrrole rings and non-conventional O—H...Cl hydrogen bonds between the oxygen atom of the water axial ligands and the chloride of neighboring phenyl groups. Hirshfeld surface analysis indicates that intermolecular contacts are dominated by H...H (50.2%), followed by H...Cl (21.6%) and H...C (21.2%) interactions, then by less chemically meaningful C...Cl (6.0%) contacts.

The non-H part of the molecule of the title compound, C 13 H 15 N 3 O 3 , is nearly planar, with the 2-cyano- N ′-[(1E)-ethylidene]acetohydrazide moiety and the dimethoxy phenol ring forming a dihedral angle of 2.5 (1)°. Intermolecular N—H...O, C—H...O and C—H...π interactions are mainly responsible for the cohesion within the crystal structure. The intermolecular interactions were quantified and analysed using Hirshfeld surface analysis, revealing that H...H interactions contribute most to the crystal packing (36.9%). The volume of the crystal voids was calculated to be 167.8 Å 3 (13% of the unit-cell volume).

A complex combination of Mn(II) acetate with 3-amino-1,2,4-triazole with polymer structure [C3.556H6.222Mn0.444N3.556O1.778] was synthesized. The composition and structure of the synthesized complex were determined using modern physicochemical methods (IR spectroscopy, elemental analysis, thermal analysis, X-ray diffraction analysis, and Hirschfeld surface analysis). Based on derivative analysis, the causes of endo- and exo-effects were determined, and the thermal products were identified. X-ray diffraction analysis showed that in the formation reactions of the 3-amino-1,2,4-triazole complex, the central atom of the triazole forms a polymer structure through monodentate coordination through nitrogen atoms. ring, and the oxygen atom of the acidic ligand with manganese. According to Hirshfeld surface analysis, the most important effects on the crystal structure correspond to the pair of atoms H•••H (51.8%) and H•••O/O•••H (20.6%). interaction between the hydrogens of the methylene and benzene rings

The escalating crisis of bacterial resistance necessitates the development of novel antimicrobial agents. Herein, we report the synthesis and comprehensive characterization of a new zinc-(II) coordination compound, [Zn-(phen)-(maleate)-(H2O)]·H2O (phen = 1,10-phenanthroline). Single-crystal X-ray diffraction revealed a distorted square pyramidal geometry around the Zn-(II) center, forming a supramolecular framework (triclinic, ) stabilized by hydrogen bonding (H···O/O···H: 30.6%) and π-π stacking interactions (C···C: 9.0%), as quantified by Hirshfeld surface analysis. Periodic density functional theory (DFT) calculations confirmed a direct energy gap of 3.45 eV and thermodynamic stability under ambient conditions. Vibrational spectroscopy (infrared and Raman) combined with DFT calculations provided suitable mode assignments. The compound exhibited selective antibacterial activity against Gram-positive Streptococcus mutans (MIC = 1000 μg/mL) with no activity against Gram-negative Escherichia coli. Systematic control experiments confirmed that antibacterial activity originates from the intact coordination complex rather than individual components. In silico pharmacokinetics predictions indicated favorable gastrointestinal absorption, full compliance with drug-likeness rules (Lipinski, Ghose, Veber, Egan, Muegge), and no cytochrome P450 inhibition. Molecular docking studies revealed specific binding to a S. mutans enzyme (ΔG = -7.4 kJ/mol), suggesting enzyme inhibition as the primary mechanism. This work establishes a multidisciplinary framework for rational Zn-coordination compounds design while highlighting critical needs for toxicological validation and structural optimization to enhance potency and broaden antimicrobial spectrum.

Synthesis, structure, DFT calculation, Hirshfeld surface analysis, molecular docking, and biological studies of bis[S-benzyl-β-N-(3-phenyloxybenzyl- methylene)dithiocarbazato] Cu(II) and Ni(II) complexes