Intermolecular Interaction Energies Research Articles

Molecular Hydrogen Acts as a Hydrogen Bond Proton Acceptor: From Protonated Betaine Tagging to the Weakest Hydrogen Bond.

In an attempt to gain further insights into the intermolecular interactions implied by Rizzo's group's cautionary tale related to molecular tagging in infrared multiple photon dissociation (IRMPD) spectroscopy with molecular messengers [Masson, A. . J. Chem. Phys. 2015, 143, 104313], in the present study, we provide an in-depth analysis of the noncovalent interaction between the molecular hydrogen and protonated betaine molecule in the gas phase. We aim to shed some new light on the fundamental issues concerning the wide diapason of hydrogen-bonding-type intermolecular interactions, with a wide variety of proton acceptors. We demonstrate that in the course of tagging the protonated betaine with molecular hydrogen from the OH group side, it is the σ bond of molecular hydrogen that plays the role of hydrogen-bonding proton acceptor. The tagging thus induces a small yet significant red shift of the protonated betaine O-H stretching mode. We investigate the performance of a wide range of density functional theory (DFT) functionals for the calculation of anharmonic vibrational frequency shifts of the studied system, which are essential for the correct interpretation of the experimental IRMPD data. For an accurate prediction of the OH stretching frequency shifts, specifically designed functionals such as Handy's group HCTH/407 should be applied. The empirical dispersion correction enhances the systematic overestimation of the anharmonic frequency shift, characteristic of the most widely used DFT functionals. Combining the full-wave function approach with the charge field perturbation and natural bond orbital (NBO) deletion analyses, we demonstrate that the frequency shift in the OH-tagged structure is governed by the σHH → σ*OH intermolecular charge transfer. This interaction stabilizes the OH-tagged dimer as well, in contrast to the dipole-quadrupole electrostatic interaction energy term. Topological analysis of the electron density reveals the presence of an intermolecular bond critical point with a positive value of the density Laplacian very close to the lower limit for hydrogen bonds. NCI analyses demonstrate that the OH···H2 interaction is weaker than the intramolecular CH···O one within the protonated betaine molecule, with the through of reduced density gradient appearing at less negative sign(λ2)·ρ values. Analyzing the O-H stretching vibrational potential with the second-generation absolutely localized molecular orbitals energy decomposition analysis (ALMO-EDA 2) revealed that in the case of betaineH(+) tagged from the OH group side, the permanent electrostatics (ΔEelec), polarization (ΔEpol), and charge-transfer (ΔEct) contributions to the total intermolecular interaction energy contribute favorably to the weak hydrogen bond formation and to the red shift of the fundamental O-H stretching frequency, the ΔEct contribution being the most significant in the last context. The Pauli repulsion term, on the other hand, favors an O-H stretching frequency blue shift as a consequence of the vibrational confinement effects.

Phase behaviour and internal mechanism of action of two solvents for the separation of butanol isomers from industrial wastewater

Industrial wastewater usually contains large amounts of butanols which form azeotropic mixtures with water. Efficiently and cleanly separating these azeotropes while saving energy is an urgent problem to solve. This study used two types of solvents to measure the ternary liquid-liquid equilibrium (LLE) data for extracting n-butanol, sec-butanol, and tert-butanol from water at 298.2 K and 101.3 kPa. The obtained data was correlated with NRTL and UNIQUAC models to obtain relevant binary interaction parameters. The reliability of the binary interaction parameters was verified using a Gibbs energy topology-based mixture surface analysis method. The root mean square deviations of the two models were less than 0.0061 and 0.0072, respectively, indicating that both the NRTL and UNIQUAC models could correlate the experimental data well. The extraction performance was evaluated using the distribution coefficient (D) and the separation factor (S). Isopentyl acetate showed better extraction performance, and the differences in the molecular structures of butanols also showed regularity during the extraction process. Combined with quantum chemistry calculations, the hydrogen bond donors and acceptors between six ternary systems were analyzed using the COSMO-SAC method. The intermolecular interaction energies were calculated using the Dmol3 module. Finally, through IGMH and AIM analysis, it was proved that the difference in hydrogen bond strength between isopentyl acetate/ethyl acetate and butanols with different molecular structures is the reason for this difference. This study provides basic data and parameters for the design of butanols extraction processes through a combination of experiments and quantum chemistry calculations.

Effect of functionalization on the adsorption performance of carbon nanotube as a drug delivery system for imatinib: molecular simulation study

In this study, efficiency of functionalized carbon nanotube as a potential delivery system for imatinib anti-cancer drug was investigated. Accordingly, carboxyl and hydroxyl functionalized carbon nanotube were inspected as a notable candidate for the carriage of this drug in aqueous media. For this purpose, possible interactions of imatinib with pure and functionalized carbon nanotube were considered in aqueous media. The compounds were optimized in gas phase using density functional calculations. Solvation free energies and association free energies of the optimized structures were then studied by Monte Carlo simulation and perturbation method in water environment. Outcomes of quantum mechanical calculations presented that pure and functionalized carbon nanotubes can act as imatinib drug adsorbents in gas phase. However, results of association free energy calculations in aqueous solution indicated that only carboxyl and hydroxyl functionalized carbon nanotubes could interact with imatinib. Monte Carlo simulation results revealed that electrostatic interactions play a vital role in the intermolecular interaction energies after binding of drug and nanotube in aqueous solution. Computed solvation free energies in water showed that the interactions with functionalized carbon nanotubes significantly enhance the solubility of imatinib, which could improve its in vivo bioavailability.

A Rotational Study of 2-tert-Butylphenol and Its 1 : 1 Argon Complex.

The chirped-pulse Fourier Transform microwave spectrum of 2-tert-butylphenol, an industrial intermediate for the production of antioxidants, has been investigated in the 2-8 GHz frequency range. The spectral analysis has allowed obtaining precise structural information on the most stable conformer and its complex with argon. The conformation of the monomer reveals that the hydroxyl group is coplanar with the ring but points in the opposite direction to the tert-butyl group, reducing steric interactions. In the tert-butyl group one methyl group is coplanar and the other two are symmetrically staggered respect to the ring. The complex shows the rare gas sitting above the aromatic ring. Interestingly, neither the monomer nor the complex exhibit large-amplitude hydroxyl torsion motions, previously observed in 2,6-disubstituted phenols such as 2,6-di-tert-butylphenol or propofol. The experimental results are supported by computational calculations, validating the molecular structure. Additionally, symmetry-adapted perturbation theory has allowed determining the van der Waals intermolecular interaction energy of the complex.

Computational insight into the spectroscopic and molecular docking analysis of estrogen receptor with ligand 2,3-dimethyl-N[2-(hydroxy)benzylidene] aniline

A comprehensive approach encompassing a blend of spectral techniques and Density Functional Theory (DFT) was employed to elucidate the electronic, vibrational, structural, and nonlinear optical properties of 2,3-dimethyl-N[2-(Hydroxy)benzylidene] aniline (DNHBA). The investigation of this chemical compound involved a meticulous examination using spectroscopic techniques (FTIR, FT-Raman). The DFT calculations utilized the B3LYP method in conjunction with 6-311G (d, p) basis sets. The findings were substantiated by comparing the estimated vibrational frequencies and molecule geometry with experimental data. Using the Time Dependent −Density Functional Theory (TD-DFT) method to calculate the energy band gap of the compound at different solvents. We looked into frontier molecular orbitals (FMO) Molecular electrostatic potential (MEP) and natural bond analysis (NBO) to determine the compound’s kinetic stability and chemical reactivity. Hirshfeld surface (HS) analysis calculated the O–H..O, H-H and intermolecular interaction energy of the compound. The electron density distribution, interactions, and excitation within the title molecule are illustrated by performing topological analyses (RDG, ELF and LOL) using the Multiwfn software. In addition to these assessments, molecular dynamics provides an understanding of the system's dynamic development over a predefined duration during which atoms and molecules are permitted to interact. Utilizing the molecular docking approach allows us to energize the atomic-level interplay between small molecules and proteins within the binding sites of target proteins. This approach enhances our comprehension of vital biochemical processes associated with the behavior of small molecule. The intricacy and hazards associated with drug discovery and development processes have increased dramatically, leading to higher drug research costs.

Molecular dynamics simulation of the effects of base oils in barium-based greases on tribological properties based on IR and GC/MS data

Twelve kinds of base oils were characterized by a series of analytical methods to obtain detailed composition and structure information. Mineral oil and poly alpha olefin oil were mainly composed of long-chain alkanes, while ester oil was mainly composed of ester compounds. Ten of the 12 base oils were selected to synthesize barium lubricating greases. Both base oils and greases were evaluated by molecular simulation, and the corresponding molecular models were constructed based on the structural information of base oils. Grease models constructed by barium 12-hydroxystearate and ester oil exhibited the largest surface adsorption energy and intermolecular interaction energy, respectively, because polar groups in lubricant tend to adsorb on metal surface and form an absorbing film. Comparing physicochemical properties of the synthesized barium lubricating greases. The temperature resistance of grease presents a positive correlation with the simulated intermolecular interaction energy.

Valorization and protection of anthocyanins from strawberries (Fragaria×ananassa Duch.) by acidified natural deep eutectic solvent based on intermolecular interaction

This study introduces an innovative approach for the valorization and protection of anthocyanins from ‘Benihoppe’ strawberry (Fragaria × ananassa Duch.) based on acidified natural deep eutectic solvent (NADES). Choline chloride-citric acid (ChCl-CA, 1:1) was selected and acidified to enhance the valorization and protection of anthocyanins through hydrogen bond. The optimal conditions (ultrasonic power of 318 W, extraction temperature of 61 °C, liquid-to-solid ratio of 33 mL/g, ultrasonic time of 19 min), yielded the highest anthocyanins of 1428.34 μg CGE/g DW. UPLC-Triple-TOF/MS identified six anthocyanins in acidified ChCl-CA extract. Stability tests indicated that acidified ChCl-CA significantly increased storage stability of anthocyanins in high temperature and light treatments. Molecular dynamics results showed that acidified ChCl-CA system possessed a larger diffusion coefficient (0.05 m2/s), hydrogen bond number (145) and hydrogen bond lifetime (4.38 ps) with a reduced intermolecular interaction energy (−1329.74 kcal/mol), thereby efficiently valorizing and protecting anthocyanins from strawberries.

Effects of waste wood oil content on thermodynamic and structural properties of bio-asphalt and interactions between components: a molecular dynamic simulation study

ABSTRACT This study fully intends to elucidate the mechanism of waste wood oil (WWO) modifier content on the microscopic action of bio-asphalt by utilising molecular dynamics simulations. Molecular models of virgin asphalt and its components, WWO modifier, and bio-asphalt with different WWO contents were created and verified by the fluctuation parameters, radial distribution function (RDF), and thermodynamics parameters. In addition, the influence of WWO content on thermodynamic and structural properties of bio-asphalt and interactions between components was quantitatively evaluated through Hansen solubility parameter, intermolecular interaction energy, mean square displacement, RDF, and fraction of free volume. The simulation findings show that the compatibility of bio-asphalt is associated with the composition of the asphalt molecule and the compatibility ranking is not affected by the WWO content. In addition, the WWO modifier is most compatible with the resin and least with the saturate. The interaction energy between virgin asphalt and WWO and the particle migration in the asphalt models increases with increasing WWO content. Furthermore, the introduction of WWO increases the first RDF peak intensity of each asphalt component. An increase in WWO content does not change its own chemical composition. Moreover, the free volume of the system decreased as the WWO was added.

Crystal-Structure Control of Molecular Semiconductors by Methylthiolation: Toward Ultrahigh Mobility.

ConspectusThe crystal structure of organic semiconductors has been regarded as one of the crucial factors for realizing high-performance electronic devices, such as organic field-effect transistors. However, although the control of crystal structures of organic semiconductors has been examined in the last two decades of intensive efforts of the development of organic semiconductors, active measures to control crystal structures enabling high carrier mobility are still limited. In 2016, our research group noticed that regioselective methylthiolation could provide a selective crystal structure change from an ordinary herringbone structure to a pitched π-stacking structure, similar to the crystal structure of rubrene, in the benzo[1,2-b:4,5-b']dithiophene (BDT) system. Following this serendipitous finding, our group systematically investigated the relationship between the molecular and crystal structures of a range of methylthiolated aromatic and heteroaromatic compounds.This Account provides a comprehensive overview of our research efforts and advancements in the development of methylthiolated small-molecule-based organic semiconductors (molecular semiconductors). We first describe the outline of the past development of molecular semiconductors, focusing on the types of crystal structures of high-performance molecular semiconductors. Then, we describe our findings on the drastic crystal structure change in the BDT system upon methylthiolation, detailing the causes of the change in terms of the intermolecular contacts and intermolecular interaction energies. This is followed by the confirmation of the generality of the crystal-structure change by methylthiolation of a series of acene and heteroacenes, where the herringbone structure in the parent system is unexceptionally transformed into the pitched π-stacking structure, a promising crystal structure for high-mobility molecular semiconductors well exemplified by the prototypical molecular semiconductor, rubrene. In fact, the methylthiolated anthradithiophene afforded comparable high mobility to rubrene in single-crystal field-effect transistors. Then, we demonstrate that the sandwich herringbone structures of peri-condensed polycyclic aromatic hydrocarbons, including pyrene, perylene, and peropyrene, change into brickwork crystal structures upon methylthiolation and that, among these compounds, very promising molecular semiconductors, methylthiolated pyrene and peropyrene, showing ultrahigh mobility of 30 cm2 V s-1, are realized.Through the studies, by gaining insights into the underlying mechanisms driving the crystal structure changes, we lay a strong foundation for tackling challenges related to controlling the crystal structures and developing high-performance molecular semiconductors. This will be a distinct approach from the past activities in the development of molecular semiconductors that mainly focused on molecules themselves, including their synthesis, properties, and characterization. We thus anticipate that our findings and the present Account will open the door to a new era of the development of molecular semiconductors.

Structural and Dynamic Analyses of Pathogenic Variants in PIK3R1 Reveal a Shared Mechanism Associated among Cancer, Undergrowth, and Overgrowth Syndromes.

The PI3K enzymes modify phospholipids to regulate cell growth and differentiation. Somatic variants in PI3K are recurrent in cancer and drive a proliferative phenotype. Somatic mosaicism of PIK3R1 and PIK3CA are associated with vascular anomalies and overgrowth syndromes. Germline PIK3R1 variants are associated with varying phenotypes, including immunodeficiency or facial dysmorphism with growth delay, lipoatrophy, and insulin resistance associated with SHORT syndrome. There has been limited study of the molecular mechanism to unify our understanding of how variants in PIK3R1 drive both undergrowth and overgrowth phenotypes. Thus, we compiled genomic variants from cancer and rare vascular anomalies and sought to interpret their effects using an unbiased physics-based simulation approach for the protein complex. We applied molecular dynamics simulations to mechanistically understand how genetic variants affect PIK3R1 and its interactions with PIK3CA. Notably, iSH2 genetic variants associated with undergrowth destabilize molecular interactions with the PIK3CA receptor binding domain in simulations, which is expected to decrease activity. On the other hand, overgrowth and cancer variants lead to loss of inhibitory interactions in simulations, which is expected to increase activity. We find that all disease variants display dysfunctions on either structural characteristics or intermolecular interaction energy. Thus, this comprehensive characterization of novel mosaic somatic variants associated with two opposing phenotypes has mechanistic importance and biomedical relevance and may aid in future therapeutic developments.

Experimental and theoretical studies of methyl 1-(2-chloroacetyl)-4-hydroxy-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate: Insights from synthesis, spectroscopic, crystal structure, Hirshfeld surface, DFT, ELF, RDG, IRI, ADMET and docking studies

Methyl 1-(2-chloroacetyl)-4‑hydroxy-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate (compound 2) was synthesized by the condensation of 3-carboxymethyl-2,6-diphenylpiperidine-4-one with chloroacetylchloride, and characterized by FT-IR spectroscopy. Further confirmation of the molecular structure was obtained by the single crystal X-ray diffraction (SC-XRD) technique. The study revealed that the piperidine ring adopts boat conformation with equatorial orientation of two phenyl rings at C-2 and C-6. Intermolecular contacts and hydrogen bonding interactions were explored by Hirshfeld surface and 2D fingerprint analyses, showing that the major contact were H∙∙∙H (57.7 %), C∙∙∙H/H∙∙∙C (14.2 %), O∙∙∙H/H∙∙∙O (15.3), Cl∙∙∙H/H∙∙∙Cl (7.1 %) and C∙∙∙Cl/Cl∙∙∙C (12.7 %). Intramolecular interaction was examined through the Radiant density gradient (RDG), Interaction region indicator (IRI), Electron localization function (ELF), and localized orbital locator (LOL) to understand hyperconjugration and π-electrons delocalization in the molecule. DFT studies such as structure optimization, HOMO-LUMO orbital analysis and molecular electrostatic potential were conducted for the title compound. The topology of the molecular arrangement and intermolecular interaction energies were determined through 3D energy framework analysis. Subsequently, the compound 2 was subjected to ADMET analysis to extend its scope of bioavailability. Molecular docking studies were then employed using the tyrosine kinase inhibitor, epidermal growth factor receptor (EGFR) enzymes (PDB ID: 4WKQ and 6JOL). The study revealed significant interactions between the title ligand structure and active sites of selected proteins complex.

Exploring the Reactivity of Donor-Acceptor Systems through a Combined Conceptual and Constrained DFT Approach.

In the context of the conceptual density functional theory (cDFT) and based on the computational efficiency of the constrained DFT (CDFT), we demonstrate that chemical reactivity can be governed by the difference between the local interacting chemical potentials of the reactants (referred as Edual), in agreement with Sanderson's equalization principle. In a proof-of-concept study, we investigated illustrative examples involving typical non-covalent donor-acceptor systems and reactive systems are provided. For the selected systems, our approach reveals significant mimicking between Edual and the DFT-computed intermolecular interaction energy profiles. We further evaluate the influence of the Coulomb and exchange-correlation contributions in Edual. These latter results suggest that numerous potential energy surfaces of clusters can be explored using a Sanderson-like model only based on classical interactions between molecular orbitals domains. To conclude, this study achieved a deeper understanding of the principles of cDFT and assessed, in a wider context, its efficiency in predicting the chemical reactivity.

Exploring the effect of substituents on the supramolecular assemblies built by non-covalent interactions in three closely related 1,3,4-oxadiazole-2(3H)-thione derivatives: An evaluation of antimicrobial and anti-proliferative activities

Three closely related 1,3,4-oxadiazole-2(3H)-thione N-Mannich bases were synthesized and characterized by spectroscopic and single crystal X-ray diffraction methods. X-ray analysis reveals that the title molecules adopt l-shaped conformation, and a slight structural deviation around substituent groups is noted. The Hirshfeld surface and 2D fingerprint plots demonstrate the effect of substituents (piperidine, morpholine, and thiomorpholine) on the intermolecular interactions. The CLP-PIXEL energy analysis identified the most significant interactions in the molecular dimers (that characterize the crystal packing) with respect to the total intermolecular interaction energies. These dimers are held together by various non-covalent interactions including C–H⋅⋅⋅S/N/O/Cl/π interactions in addition to unconventional lone pair⋅⋅⋅π interactions. A molecule with thiomorpholine substituent is favoured by two σ-hole interactions (Cl⋅⋅⋅Cl halogen bond and S⋅⋅⋅N chalcogen bond) in the solid state. Furthermore, the molecular electrostatic potential (MEP) surfaces and deformation electron density help to describe the existence of σ-hole on the Cl and thione S atoms. Noncovalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) methods are used to delineate the nature of observed noncovalent interactions in the molecular dimers. In vitro data of antibacterial and anti-proliferative activities indicate that compound with morpholine substituent showed a moderate antibacterial activity against all tested Gram-positive bacterial strains. However, molecules with piperidine and thiomorpholine showed notable effectiveness against the HepG-2 cell line. Molecular docking analysis was performed with two liver cancer targets, VEGFR2 and RET, in order to understand the interactions between the ligand and the active site residues of these targets.

A Machine Learning Force Field for Bio-Macromolecular Modeling Based on Quantum Chemistry-Calculated Interaction Energy Datasets.

Accurate energy data from noncovalent interactions are essential for constructing force fields for molecular dynamics simulations of bio-macromolecular systems. There are two important practical issues in the construction of a reliable force field with the hope of balancing the desired chemical accuracy and working efficiency. One is to determine a suitable quantum chemistry level of theory for calculating interaction energies. The other is to use a suitable continuous energy function to model the quantum chemical energy data. For the first issue, we have recently calculated the intermolecular interaction energies using the SAPT0 level of theory, and we have systematically organized these energies into the ab initio SOFG-31 (homodimer) and SOFG-31-heterodimer datasets. In this work, we re-calculate these interaction energies by using the more advanced SAPT2 level of theory with a wider series of basis sets. Our purpose is to determine the SAPT level of theory proper for interaction energies with respect to the CCSD(T)/CBS benchmark chemical accuracy. Next, to utilize these energy datasets, we employ one of the well-developed machine learning techniques, called the CLIFF scheme, to construct a general-purpose force field for biomolecular dynamics simulations. Here we use the SOFG-31 dataset and the SOFG-31-heterodimer dataset as the training and test sets, respectively. Our results demonstrate that using the CLIFF scheme can reproduce a diverse range of dimeric interaction energy patterns with only a small training set. The overall errors for each SAPT energy component, as well as the SAPT total energy, are all well below the desired chemical accuracy of ~1 kcal/mol.

Reliable Dimerization Energies for Modeling of Supramolecular Junctions.

Accurate estimates of intermolecular interaction energy, ΔE, are crucial for modeling the properties of organic electronic materials and many other systems. For a diverse set of 50 dimers comprising up to 50 atoms (Set50-50, with 7 of its members being models of single-stacking junctions), benchmark ΔE data were compiled. They were obtained by the focal-point strategy, which involves computations using the canonical variant of the coupled cluster theory with singles, doubles, and perturbative triples [CCSD(T)] performed while applying a large basis set, along with extrapolations of the respective energy components to the complete basis set (CBS) limit. The resulting ΔE data were used to gauge the performance for the Set50-50 of several density-functional theory (DFT)-based approaches, and of one of the localized variants of the CCSD(T) method. This evaluation revealed that (1) the proposed "silver standard" approach, which employs the localized CCSD(T) method and CBS extrapolations, can be expected to provide accuracy better than two kJ/mol for absolute values of ΔE, and (2) from among the DFT techniques, computationally by far the cheapest approach (termed "ωB97X-3c/vDZP" by its authors) performed remarkably well. These findings are directly applicable in cost-effective yet reliable searches of the potential energy surfaces of noncovalent complexes.

Unveiling the therapeutic potential of BAP from crystallographic analysis to protein docking and anticancer assessment in MCF-7 human breast cancer cells

The 4-aminoantipyrine derivatives comprising both N- and O-donor modes generate novel coordination assemblies which tend to exhibit anti-tumor activities. Crystallographic study of 1,5-Dimethyl-4- [(2-oxo-1,2-diphenyl ethylidene) amino]-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (BAP) is reported. Hirshfeld surface analysis is employed to analyze molecular electrostatic potential, inter-molecular interaction energies, and H-bonded framework. To investigate the adaptability and specificity of BAP with different protein interactions, we ran molecular docking simulations using a single ligand and many different protein targets. In this docking study, BAP crystal was selected due to its importance in cancer research, and with the different protein targets 1TNF, 2TUN, 1TNR, 5TSW, 6GK0, 6IUL, 6 K04 and 6 K05 are included. TNF-alpha, a cytokine essential for the immune system and inflammatory reactions, is generated by activated immune cells and is crucial for preventing infections and controlling cell proliferation. TNF inhibitors have improved the treatment of various ailments. TNF-alpha dysregulation is a major area of study in immunology and immunotherapy. Dihydroorotate dehydrogenase, mitochondrial enzyme, and Natterin-like proteins are also important in epigenetics and drug development. BET family proteins, including BRD2, are crucial in disease connections, cell cycle control, and gene regulation. The Swiss ADME method, which assesses medication similarity, strongly implies that the BAP may be a potential option for the treatment of breast cancer. After screening chemical libraries, BAP was shown to be an antagonist of this protein–protein interaction. In this study, the yellow tetrazolium salt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) evaluation on MCF-7 human breast cancer cells to investigate the feasible anticancer characteristics and cytotoxicity of the BAP complex.

Self-assembled Supramolecular Frameworks and Interaction Energy Studies of Acridine and Dihydroxynaphthalene based Cocrystals

Three cocrystals of acridine with 2,7-dihydroxynaphthalene (Ia and Ib) in two different polymorphs and 1,5-dihydroxynaphthalene (II) have been synthesized and characterized by single crystal x-ray diffraction method. Two polymorphs of acridine,2,7-dihydroxynaphthalene cocrystal crystallizes in same sapcegroup P-1 with different unit-cell parameters. In (Ia) the O‒H group form a syn-anti conformation whereas in (Ib) the O‒H group form an anti-anti conformation leads to the polymorphic structure of acridine, 2,7-dihydroxynaphthalene. This study reveals that the influence of π…π and C‒H…π interactions in the formation of one-, two-, and three-dimensional supramolecular frameworks when the classical hydrogen bonds such as O‒H…N and C‒H…O are limited to discrete motifs. The acridine molecules form continuous π…π stacking in the crystal structure of (Ia) and discrete π…π stacking in the crystal structure of (Ib) and (II). The conformational flexibility of the substituted hydroxy group has an influence in the supramolecular frameworks of the three-dimensional crystal structure. The intermolecular interaction energy calculation between the molecular pairs has been carried out to study the strength of the interaction and its dependence on the geometrical parameters.

Ammonium carboxylate salts: the additivity of intermolecular interaction energies in charged organic compounds

The supramolecular organization of organic salts has been widely researched, revealing recurring patterns in crystalline lattices that describe their supramolecular properties.

The crystal structure of hexaphenylbenzene under high hydrostatic pressure

High-pressure single-crystal X-ray diffraction, intermolecular interaction energy calculations, and density functional theory are used to examine the structure and emission properties of hexaphenylbenzene during hydrostatic compression to 4.14 GPa.

Novel supramolecular co-crystal of 8-hydroxyquinoline with acetone-(2,4-dinitrophenyl)hydrazone: One pot synthesis, structural characterization, Hirshfeld surface and energy framework analysis, computational investigation and molecular docking study

Inspired by Betti reaction, a novel co-crystal of 8-hydroxyquinoline with acetone-(2,4-dinitrophenyl) hydrazone (I) was isolated in a one-pot 3 component assembly by reacting 8-hydroxyquinoline (8-HQ) with 2,4-dinitrohydrazine (DNPH) and formaldehyde. The crystal structure of (I) was characterized by single crystal X-ray diffraction analysis which shows that the hydrogen bonding and π-π stacking are the main driving forces for the co-crystal building. The topology of the intermolecular interaction energies in the crystal packing was analyzed and exposed using 3D energy framework analysis. The calculations of the studied molecule at the B3LYP levels in the 3-21g, 6-31g and 6-31++g** basis sets were made using the Gaussian package program. Theoretical calculations were executed to develop optimized geometry, frontier molecular orbital analysis and the NLO properties of the considered molecule, Furthermore, Molecular docking calculations were made. Afterwards, the interactions occurring in the docking calculation against the anti-oxidant protein (ID: 1HD2, 3NRZ, 4Z8D) were examined in detail with Schrödinger maestro.