Hirshfeld Analysis Research Articles

Synthesis, crystal structure and Hirshfeld analysis of N-ethyl-2-{3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclo-pent-2-en-1-yl-idene}hydrazinecarbo-thio-amide.

The title compound (C14H23N3S, common name: cis-jasmone 4-ethyl-thio-semicarbazone) was synthesized by the equimolar reaction of cis-jasmone and 4-ethyl-thio-semicarbazide in ethanol facilitated by acid catalysis. There is one crystallographically independent mol-ecule in the asymmetric unit, which shows disorder of the terminal ethyl group of the jasmone carbon chain [site-occupancy ratio = 0.911 (5):0.089 (5)]. The thio-semicarbazone entity [N-N-C(=S)-N] is approximately planar, with the maximum deviation of the mean plane through the N/N/C/S/N atoms being 0.0331 (8) Å, while the maximum deviation of the mean plane through the five-membered ring of the jasmone fragment amounts to -0.0337 (8) Å. The dihedral angle between the two planes is 4.98 (7)°. The mol-ecule is not planar due to this structural feature and the sp 3-hybridized atoms of the jasmone carbon chain. Additionally, one H⋯N intra-molecular inter-action is observed, with graph-set motif S(5). In the crystal, the mol-ecules are connected through pairs of H⋯S inter-actions with R 2 2(8) and R 2 1(7) graph-set motifs into centrosymmetric dimers. The dimers are further connected by H⋯N inter-actions with graph-set motif R 2 2(12), which are related by an inversion centre, forming a mono-periodic hydrogen-bonded ribbon parallel to the b-axis. The crystal structure and the supra-molecular assembly of the title compound are compared with four known cis-jasmone thio-semicarbazone derivatives (two crystalline modifications of the non-substituted form, the 4-methyl and the 4-phenyl derivatives). A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are from H⋯H (70.7%), H⋯S/S⋯H (13.5%), H⋯C/C⋯H (8.8%), and H⋯N/N⋯H (6.6%) inter-faces (only the disordered atoms with the highest s.o.f. were considered for the evaluation).

A comparative study of second order Non-linear optical crystals derived from chloro- and dichloro- aniline

Followed by one-pot mechanism Schiff base products derived from the substituted anilines are crystallized by the slow-evaporation technique. Both crystals are characterized by FT-IR, 1H NMR and 13C NMR spectral studies. Single crystal XRD analysis provides data of both crystals and it is well fitted with NMR and IR spectral results. The obtained results of IR frequencies and NMR chemical shifts are compared with theoretical predicted results obtained from DFT method. The energy gap Eg was calculated by HOMO and LUMO and other theoretical parameters are determined by using DFT method with B3LYP/6–311++ G (d,p) basis set and the energy gap is very small 3.59, 3.52 eV for PCA and DCA crystals. The supramolecular investigation of crystal structure explained by Hirshfeld analysis. Using quantum computations techniques, the topological parameters LOL and ELF, scatter graph and diagram of the crystals was the further characterization. The first order hyperpolarizability (β0) was calculated by B3LYP/6–311++ G (d,p) basis set. Using the Kurtz-Powder technique, the second order Non-linear optical activity of the crystal was obtained. Based upon these crystals, which are outstanding Nonlinear optical activity material and best for the laser safety devices.

Synthesis and structural characterization of poly-thiolactones with varied ring sizes and endocyclic functional groups

The synthesis and isolation of new thiolactone species containing endocyclic ether, polyether, and lactone groups were designed using the reaction between diacyl chlorides with organometallic tin compounds as a template for controlled thioester bond formation. Thus, eight polythiolactones, including cyclo and spiro compounds with different ring sizes and functional groups were prepared, namely 1-oxa-4,9-dithiacycloundecane-5,8-dione (1a), 1-oxa-4,10-dithiacyclododecane-5,9-dione (1b), 1,4-dioxa-7,12-dithiacyclotetradecane-8,11-dione (2a), 1,4-dioxa-7,13-dithiacyclopentaecane-8,12-dione (2b), 2,15,19,32-tetraoxa-6,11,23,28-tetrathia-spiro[16.16]tritriacontane 3,7,10,14,20,24,27,31-octaone (3a), 2,16,20,34-tetraoxa-6,12,24,30-tetrathia-spiro[17.17]pentatriacontan-3,7,11,15,21,25,29,33-octaone (3b), 9,12,25,28-tetraoxa-6,15,22,31-tetratia-1(1,4),17(1,4)-diphenylcyclodotriacontane-5,16,21,32-tetraone (2c), and 2,17,21,36-tetraoxo-6,13,25,32-tetrathia-8(1,4)27(1,4)-diphenyl-spiro[18-18]heptatriacontane-3,7,12,16,22,26,31,35-octaone (3c). The structural characteristics of the eight closely related derivatives were determined by examining the impact of ring size and functional groups, through single-crystal X-ray diffraction techniques. The crystal packing of these polythiolactones was found to be mainly governed by weak C-H···O hydrogen bonding and van der Waals interactions, resulting in partially overlapping tubular arrangements. Hirshfeld analysis was performed to investigate the crystal packing and intermolecular interactions. The results of this study show the possibility of forming 3D tubular arrangements using polythiolactones with various endocyclic groups, including both flexible and rigid spacers.

A theoretical approach to the corrosion inhibition of iron in acidic solution by a green formulation derived from Nigella sativa L seeds oil

A theoretical approach combining density functional theory (DFT) computation, Monte Carlo (MC) methods, and molecular dynamics (MD) simulations was used to investigate and validate the iron corrosion inhibition performances in the acidic medium of a green formulation based on the oil extracted from Nigella sativa L. DFT calculations allowed to determine the energetic, global, and local chemical reactivity parameters. The most stable adsorption configuration of the fatty acids components of the Nigella sativa L. formulation was determined by the Monte Carlo methods with the adsorption locator module and by molecular dynamics simulations. Results indicated that all the compounds are absorbed with a totally flat orientation on the first layer of the metal surface.The active sites of molecules were effectively established by using DFT through the analysis of frontier molecular orbitals (FMO), the Hirshfeld population analysis (HPA), the electrostatic potential (ESP), molecular electron density analysis (MED), and Fukui indices (FI). The solvent effect was investigated by using the conductor-like polarizable continuum model (CPCM). Protonation effects were also analysed through the protonation energy (PE), the proton affinity (PA), and the absolute gas phase basicity (GB). The formation of a coating on the iron surface validated the good protective action of the green formulation derived from Nigella sativa L.The computational and theoretical approaches substantiate our experimental electrochemical and spectroscopic studies [1].

New heteroleptic l-argininato copper(II) complex with bromide and N, N’– heterocyclic ligands – synthesis, supramolecular, spectroscopic, magnetic and theoretical investigations

A new heteroleptic [CuBr(l−Arg)(bpy)]Br·2H2O (1) (l−Arg=l−Arginine, bpy=2,2’−bipyridine) complex has been synthesized and its molecular and supramolecular structure aspects have been discussed based on the X−ray single crystal structure and Hirshfeld analyses. In addition, the properties of complex 1 have been elucidated using different spectroscopic methods (FT−IR / FIR, Raman, NIR−Vis−UV, Q− / X− band EPR) and magnetic measurements. In this complex, the bromide anion occupies the apex of a slightly distorted square pyramid (τ = 0.12). The [CuBr(l−Arg)(bpy)]+ complex units exhibit a ribbon−like organization, with Cu(II) metal centers located at the corners of triangles where the shortest Cu∙∙∙Cu distance is 5.579 Å. The aromatic moieties of bpy are aligned nearly parallel leading to π···π interactions. Both, non−bonded and coordinated, Br− ions act as hydrogen−bond acceptors for guanidinium groups. Hirshfeld analysis indicated the importance of the Br∙∙∙H (17.9 − 18.4 %), O∙∙∙H (14.9−15.2 %), and H∙∙∙H (42.3−43.1 %) interactions in the molecular packing of the studied complex. Atoms in molecules (AIM) calculations indicated mainly the closed shell character for the Cu−N, Cu−O and Cu−Br coordination interactions. The G value calculated using the Q−band EPR spectra parameters g|| = 2.235 and g⊥= 2.05 is 4.7, what indicating negligible coupling and that local tetragonal axes are aligned parallel. A negative value of Weiss temperature θCW = -0.32 K indicates the presence of weak antiferromagnetic coupling between the neighboring Cu(II) ions mediated through hydrogen bonds and π-π stacking of aromatic moieties of bpy. The value of gav= 2.113 obtained from Q−band EPR spectra is consistent with that corresponding to the Curie constant (C = 0.4138 emu K mol−1), i.e.g = 2.101, and that obtained from the best fitting to the Brillouin function: g = 2.139.

Crystal growth, Hirshfeld analysis, optical, thermal, mechanical, and third-order non-linear optical properties of Cyclohexylammonium picrate (CHAP) single crystal

The organic single crystals of Cyclohexylammonium picrate (CHAP) had been grown using the method of slow evaporation solution growth. A determination was made regarding the solubility of the substance. The crystal's lattice cell parameters and morphology were characterized using single-crystal X-ray diffraction and powder X-ray diffraction techniques. The HRXRD techniques were utilized to assess the crystal quality. The functional groups of CHAP material were identified through the use of FT-IR and FT-Raman analysis. A Hirshfeld surface analysis was performed to investigate the formation of hydrogen bonds between N–H⋯O and C–H⋯O molecules. The grown crystals were examined in optical and thermal investigations utilizing UV–visible and TGA, DSC techniques. Mechanical analysis is used to quantify surface properties, such as work hardening coefficient and void volume. Z-scan analysis was utilized to calculate the non-linear refractive index (n2), nonlinear absorption (β), and third-order non-linear susceptibility (χ3).

Noncovalent interactions and electron transfer between 1,3,5-trinitro-1,3,5-triazinane and Al3O3−

As the first step in energy transfer from oxide passivated metal nanoparticles/surface defects to an energetic molecule for the controlled dissociation of the latter, the nature of the weak interactions between 1,3,5-trinitro-1,3,5-triazinane (RDX) and Al3O3− isomers are studied as a model system by DFT method with PBE0 functional and different basis sets (TZVP, Def2-TZVPP, TZ2P). Different electron density (NCI, IGMH, QTAIM, IQA, EDA-NOCV) and charge analysis methods (Hirshfeld, Hirshfeld-I, NPA) reveal that partial charge-transfer from Al3O3− to RDX via the CH···O (1.851–2.481 Å, O(2p)-to-C-H(σ*) type) and the CH···Al (2.836–2.871 Å, Al(3p)-to-C-H(σ*) type) interactions are possible. Hirshfeld analysis predicts 6–25% transfer of the -1 charge to RDX while Hirshfeld-I and NPA predict 7–22% and 2–7%, transfer, respectively. Al3O3− (HOMO)-RDX (LUMO+n, n = 0–3) type interactions including the charge transfer via the (ON)O···Al (2.846–3.511 Å) interactions are found to excite the Al3O3− (kite) anion. The binding energies are in the -10 to -31 kcal/mol range. Vertical detachment energies of the complexes are within 2.5–3.9 eV, higher than the bare Al3O3− isomers by 0.3–1.3 eV. Complexation weakens the RDX structure and reduces the CH stretching frequencies by 10–350 cm−1. Modulations in the bond lengths in the Al3O3− isomers shift the frequencies in the 0–1300 cm−1 region. New intermolecular vibrations enrich the terahertz region of the IR spectra.

Synthesis and characterizations of Hg (II) Complex of Macrocyclic complexes compounds Tetradecahydrodibenzo hexaazacyclooctadecine with HgX2 (X= Cl, Br) by Hirshfeld analysis and antimicrobial activity

This study examines the synthesis and characterization of a macrocyclic complex molecule having the general formula [M-LX2], where M =Hg (II) with schiff base Tetradecahydrodibenzo hexaazacyclooctadecine ligands. Resulted from the interaction between mercury and the diethyl triamine and benzene- 1, 2 diol in an ethanolic solution. Schiff base and its novel mercury (II) Complexes were studied vibrational in the solid state using spectral, 1H-NMR, IR, UV, and antimicrobial activity approaches. We were able to establish the coordination mode of the metal in complexes by comparing the changes in the ligands' and complexes' FT-IR and UV-Visible spectra.
 Keywords: MERCURY (II), Schiff bases, IR, 1H-NMR, PXRD Spectroscopy.

Unveiling Hierarchies and Structural Complexity in Silicon-Based Crystals: Insights into their Structural, Elastic, and Radiation Properties through Hirshfeld Analysis

Unveiling Hierarchies and Structural Complexity in Silicon-Based Crystals: Insights into their Structural, Elastic, and Radiation Properties through Hirshfeld Analysis

Two-dimensional III-nitrides: A comprehensive DFT and thermodynamics studies

We used DFT simulations for a comprehensive investigation of the stability, corrected electronic band gap, thermodynamic properties and bonding nature of the 2D III-nitrides. The geometry relaxation indicates that all the structures are stable, verified by phonon and molecular dynamics (MD) simulations. The phonon plot shows that all the vibrations are real and there is no imaginary vibration observed. The MD simulations at 500 K for the period of 1ps signify stable structures without any structural distortion. The AIM analysis demonstrates that the electron density, Laplacian and energy density values for X–N (X = B, Al, Ga and In) bonds are in the range of 0.10–0.185 au, 0.36–0.64 au and −0.029 to −0.16 au, which evidenced the partial ionic bonding nature of III-nitrides. The Hirshfeld density analysis shows that significant charge transfer occurred between the X and N atoms. The band gap study performed by HSE06, shows that the BN, AlN, GaN and InN have a band gap value of 5.65, 4.9, 3.45 and 2.0 eV, which are in good agreement with the experimental values compared to other reported theoretical results. This study would be helpful for scientists in the future exploration of 2D III-nitrides for energy, catalysis, optics applications.

2-(((2,4-Dichlorophenyl)imino)methyl)-3,4-difluorophenol: X-ray, DFT, MEP, HOMO-LUMO, NLO, Hirshfeld Surfaces, ADMET Profiling, Target Identification, Antipsychotic Activity Against Dopamine D2 and Serotonin 5-HT2A Receptors

Halogenated compounds, especially fluorine and chlorine, play a key role in drug development. They account for a large proportion of all approved drug molecules. The importance of these two halogens stems from their remarkable effects on biological activity and pharmacokinetic properties. The study presented here aims to give the results obtained by the DFT methods and in silico medicinal evaluations of a newly synthesized small molecule. The small molecule belongs to the Schiff base class of organic compounds and is substituted with halogen atoms. The tetrahalogenated compound (THSB) Schiff base, 2-(((2,4-dichlorophenyl)imino)methyl)-3,4-difluorophenol, was first synthesized via the classical condensation method and then characterized by spectroscopic techniques. The THSB optimized by the B3LYP method was evaluated in terms of geometrical parameters, surface area (MEP and Hirshfeld analysis) and secondary interaction analysis, NLO properties, and electronic properties (HOMO-LUMO and UV-Vis). Second, THSB was evaluated regarding medicinal chemistry, physicochemical and pharmacokinetic properties, and toxicity (ADMET). Then, we comprehensively investigated the potential biological targets of THSB. Using the results of the SwissSimilarity analysis, we investigated the antagonistic effects of THSB against serotonin 5-HT2A and dopamine D2 receptors. Docking results were compared with the known antipsychotics, clozapine and risperidone. THSB showed a higher antagonistic effect than clozapine for the D2 receptor. However, risperidone proved to be the most effective antagonist for both targets. The binding energies of THSB, risperidone, and clozapine were -8.30, -11.84, and -8.07 kcal/mol, respectively, for D2; those of THSB, risperidone, and clozapine were -6.94, -11.47, and -10.10 kcal/mol, respectively, for 5-HT2A.

Synthesis, crystal structure, spectroscopy and quantum chemical investigations of hexahydroquinoline molecule

The synthesis and crystal structure of benzyl 4-([1,1'-biphenyl]-4-yl)-2-methyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate are described. Single crystal X-ray diffraction of title molecule was used to investigate the crystal structure. The most stable optimised structure was identified using the B3LYP/6-31 + G(d) method. IR, 1H-NMR and elemental analysis of the title compound were performed. Besides, frontier molecular orbitals, molecular electrostatic potential, and thermodynamic properties were investigated by theoretically. In order to explore the nonlinear optical properties were performed theoretically. Hirshfeld analysis was also performed to determine the interactions of the molecule.

A 1D Sb-containing hybrid organic-inorganic material: Synthesis, structural characterization, hirshfeld surface, thermal behavior, vibrational and optical properties

A novel interesting hybrid organic-inorganic material of Bis (2-amino-3-nitropyridinuim) pentachloroantimoinates (III) with the formula [C5H6N3O2]2SbCl5 was elaborated by slow evaporation at room temperature. This compound was crystallized in the monoclinic system with the P 21/c space group, as shown using the X-ray diffraction results. The parameters are the following: a = 16.484(6) Å, b = 7.7170 (19) Å, c = 16.159 (7) Å, β= 109.26(5)°, Z = 4 and V = 1940,5(14) Å3. The asymmetric unit consists of one Sb (III) cation surrounded by five Cl− and two protonated cations 2-amino-3-nitropyridinuim. The crystal packing cohesion was maintained by NH…Cl and NH…O hydrogen bonds to form a three- dimensional network. The infrared IR and Raman studies which were recorded at room temperature in the 4000–400 cm−1 and 0–4000 cm−1 frequency regions, respectively, confirmed the existence of vibrational modes that correspond to the organic and inorganic groups. The Hirshfeld analysis results show that the predominate interactions were H…Cl and O…H contacts (39.9, 14.5 % respectively). The Thermogravimetric analysis TGA shows that this compound remains stable up to about 150 °C. The optical properties were characterized experimentally by UV–visible absorption studies and photoluminescence measurements. The Photoluminescence spectrum manifests a broad and strong band of luminescence around 454 nm (2.73 eV), which can be even observed with the naked eye at room temperature and is due to exciton emission.

Long-Chain Bio-Based Nylon 514 Salt: Crystal Structure, Phase Transformation, and Polymerization.

Nylon 514 is one of the new long-chain bio-based nylon materials; its raw material, 1,5-pentanediamine (PDA), is prepared by biological techniques, using biomass as the raw material. The high-performance monomer of nylon 514, 1,5-pentanediamine-tetradecanedioate (PDA-TDA) salt, was obtained through efficient crystallization methods. Here, two crystal forms of PDA-TDA, anhydrous and dihydrate, were identified and studied in this paper. From the characterization data, their crystal structures and thermal behaviors were investigated. Lattice energy was calculated to gain further insight into the relationship between thermal stability and crystal structures. The contribution of hydrogen bonds and other intermolecular interactions to the crystal structure stability have been quantified according to detailed Hirshfeld and IRI analyses. Additionally, the transformation mechanism of the anhydrate and dihydrate was established through a series of well-designed stability experiments, in which the temperature and water activity play a significant role in the structural stability of crystalline forms. Eventually, we obtained nylon 514 products with good thermal stability and low absorption using stable dihydrate powders as monomers. The properties of nylon 514 products prepared by different polymerization methods were also compared.

The Molecular Structural Analysis of Biologically Important Catechol Molecule: An Integrative Perspective from Experiments and Futuristic Tools

Background: Catechol is a phenolic molecule found naturally in plants. It is also known as pyrogallic acid or 1, 2-dihydroxybenzene. Catechol is currently produced commercially by decarboxylating gallic acid at high temperatures and pressures. Aims and Objectives: This research aimed to understand the biological importance of catechol and perform molecular structural analysis on catechol molecules. Methods: Catechol (1, 2, dihydroxy benzene) was studied via computational analysis by employing the use of DFT and B3LYP methods. Hirshfeld analysis was carried out to investigate crystal intermolecular interactions, and the NBO study was performed to study chemical donating and accepting interactions. Moreover, the computational study was performed using FTIR, HNMR and other instrumentation like AIM theory for circular dichroism data. Results: Furthermore, the surface iso-projection study and binding energy results did prove to run in alignment with experimentally obtained values from the computational studies. Fukui functional study and molecular electrostatic potential were utilized in the study to investigate interactions between anionic and cationic sites of catechol. In addition, molecular dynamic simulations revealed that biomolecular stability was also present. Thus, the antibiotic efficacy of catechol displayed chemical oxidative interactions that exhibited close chemical correlations with ascorbic acid, ellagic acid, and gallic acid. Conclusion: The catechol has been examined experimentally and theoretically. The results were compared with catechol spectra, including IR and UV-visible spectra generated through computer analysis. The experimentally observed spectra were found to be in parallel with theoretical data. According to drug-likeness investigations, the following compounds, gallic acid, ellagic acid, and ascorbic acid, were found to be closely related to catechol as an antibiotic. Hence, it can be concluded that catechol, whether in its entirety or in a portion, is a potent antibacterial, anti-inflammatory, and anti-malarial drug.

P‐toluenesulfonychloride‐based niosomes for Amphotericin‐B against Leishmaniasis

AbstractNonionic‐surfactants have been reported as nanocarriers for delivering low bioavailable drugs at the target sites. In the current study, two new nonionic surfactants were synthesized to enhance the oral bioavailability of the low water‐soluble antifungal drug Amphotericin‐B. The hemolysis effect of nonionic surfactants on red blood cells and cytotoxicity against the 3T3 cell line was studied. Both surfactants have shown low hemolysis and cytotoxicity as compared to standard Tween 80. The morphology of drug‐loaded niosomes of nonionic surfactants 1 and 2 was studied by using atomic force microscopy (AFM), and both surfactants based vesicles were spherical, while their average sizes were measured by dynamic light scattering (DLS). The average size, zeta potential and polydispersity index (PDI) values of surfactants 1 and 2 were 282 ± 3 nm, −8 ± 1 mV, 0.26 and 287 ± 3 nm, −10 ± 1 mV, 0.24. The drug entrapment efficiency and critical micelle concentrations of nonionic surfactants were determined by using UV–visible spectroscopy. The structures of surfactants 1 and 2 were assessed through single‐crystal x‐ray crystallographic analysis, while Hirshfeld analysis was performed to study the intermolecular interactions of molecules, as well as the packing behavior of their crystals. The nonionic‐surfactant 1 was further tested for antileishmanial activity against Leishmania tropica promastigotes, in both drug‐loaded and unloaded niosomal vesicular forms. The nonionic surfactant 1 was found to be a potentanti‐leishmanial agent in the drug‐loaded form with IC50 = 3.02 ± 0.91 μM in comparison to their standard drugs Amphotericin‐B (IC50 = 3.8 ± 0.04 μM) and miltefosine (IC50 = 42.2 ± 0.6 μM) (p < 0.1). These results, therefore, form the basis of further results towards efficient drug delivery against tropical disease Leishmaniasis.

Comparative Analysis of Nickel-Phosphine Complexes with Cumulated Double Bond Ligands: Structural Insights and Electronic Interactions via ETS-NOCV and QTAIM Approaches.

This study presents a comprehensive analysis of nickel-phosphine complexes, specifically Ni(PH3)2(OCCH2), Ni(PH3)2(H2CCO), Ni(PH3)2(H2CCCH2), Ni(PH3)2(NNCH2), and Ni(PH3)2(η1-H2CNN). Utilizing ETS-NOCV analysis, we explored orbital energy decomposition and the Hirshfeld charges of the ligands, providing insights into the electronic structures and donor-acceptor interactions within these complexes. The interactions in the ketene and allene complexes exhibit similar deformation densities and NOCV orbital shapes to those calculated for Ni(PH3)2(NNCH2), indicating consistent interaction characteristics across these complexes. The total interaction energy for all η2 complexes is observed to be over 60 kcal/mol, slightly exceeding that of the analogous carbon dioxide complex reported earlier. Furthermore, the study highlights the stronger back-donation as compared to donor interactions across all η2 complexes. This is further corroborated by Hirshfeld analysis, revealing the charge distribution dynamics within the ligand fragments. The research offers new perspectives on the electron distribution and interaction energies in nickel-phosphine complexes, contributing to a deeper understanding of their catalytic and reactive behaviors.

Copper Coordination Dynamics: Synthesis and Structural Insights Utilizing DFT, Hirshfeld, and Antimicrobial Analysis

In this work, two copper coordination compounds, ([Cu(phen)(L)(OH)(NO3)]NO3–) (ML1) and ([Cu(L)4(H2O)2)](NO3–)2) (ML2), have been synthesized and characterized (SC-XRD). ML1 is a long polymeric chain with a stable distorted octahedral geometry that is assembled from ligands such as 1,10-phenanthroline (Phen), 2-amino-5-methyl-1,3,4-thiadiazole (L), hydroxide (OH), and nitrate (NO3–). In contrast, ML2 is made up of water molecules and L ligands, forming the usual octahedral geometry. Furthermore, in the crystal structures of ML1 and ML2, the nitrate anion is essential for the formation of distinct supramolecular clusters. To confirm the structural integrity, we applied Hirshfeld surface analysis and Density Functional Theory (DFT) computations. We also evaluated the antibacterial efficacy of these compounds computationally and experimentally, which confirmed their potential to serve as potent inhibitors of drug-resistant microbial infections.

O USO DAS FERRAMENTAS DA ANÁLISE DA SUPERFÍCIE DE HIRSHFELD NO ESTUDO DAS LIGAÇÕES NÃO-COVALENTES EM COMPLEXOS CORRELATOS

THE USE OF HIRSHFELD SURFACE ANALYSIS TOOLS IN THE STUDY OF NON-COVALENT BONDS IN RELATED COMPLEXES. The analysis of non-covalent interactions in crystalline structures through the Hirshfeld surface method using the CrystalExplorer® software has been widely used by the global scientific community over the past few decades. Although widely recognized, as far as we know, there has been no publication on this subject in the Química Nova journal. Therefore, in this work, we intended to demonstrate how these tools could be employed to study and compare the non-covalent bonds in 21 mononuclear complexes of the type [MY2(o-XPy)2], [MY2(m-XPy)2], and [MY2(p-XPy)2], where M = Zn2+ or Co2+, Y = Cl-, Br-, or I-; Py = pyridinic ligand ortho-, meta-, or para-monosubstituted by X, where X = Cl-, Br-, or I-. With a main emphasis on halogen bonds and π···π stacking interactions, the study demonstrates how Hirshfeld analysis can be used for a qualitative and quantitative comparison of non-covalent bonds, proving to be an important tool for a comprehensive understanding of the forces that stabilize these complexes in the solid-state. The study demonstrates the potential of Hirshfeld surface analysis as a valuable resource for synthetic chemists to select chemical species for rational synthesis and achieve desired properties or supramolecular arrays.

The role of intermolecular interactions in [Fe(X-salEen)2]ClO4 spin crossover complexes.

Two new spin crossover (SCO) Fe(III) compounds were prepared, their structures were analysed and their magnetic properties were investigated. An exhaustive analysis of the effects of halogen substitution and aromatic ring functionalisation on the magnetic properties of non-solvated Fe(III) perchlorate complexes has been performed. Through comparative analysis, different magnetic profiles were found for the compounds studied, namely F (1), Cl (2), H (3), Br (4a, 4b), and I (5). Using tools like Hirshfeld analysis, the study revealed patterns in octahedral distortions and deviations from the ideal octahedral geometry. The SCO phenomenon as the conducting wire in this study, emphasises the influence of intermolecular interactions on the low spin (LS) to high spin (HS) transitions in these halogen-substituted complexes. The prevalence of H⋯H contributions has been demonstrated, albeit being the weakest and an inverse strength relationship in H⋯X interactions ranging from F to I. The findings not only interpret the intricate balance between halogen substitution, functionalisation, and intermolecular interactions in modulating magnetic properties but also direct future works in designing similar molecular systems.