Strength Of Intermolecular Interactions Research Articles

Cocrystallization of Dasatinib with different acids improves the solubility and physicochemical properties: A combined experimental and theoretical studies

Dasatinib (DAS) is a tyrosine kinase inhibitor that is categorized as a class-II drug by Biopharmaceutical Classification System (BCS). It is used to treat Chronic Myeloid Leukemia (CML). The present work aimed to use the cocrystallization technique to enhance DAS's physicochemical characteristics. By applying the slow evaporation approach, we reported three DAS cocrystals with different structures of co-formers such as 4 hydroxybenzoic acid, 4-chlorobenzene acid, and Sorbic acid. Single Crystal X-ray Diffraction (SCXRD), Powder X-ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC), Thermo Gravimetric Analysis (TGA), and Fourier Transform Infrared Spectroscopy (FT-IR) were used to analyze the three obtained cocrystals. The solubility of DAS cocrystals was investigated and found to be ideally enhanced up to 6-fold, 4.5-fold, and 3.5-fold higher than DAS. According to the findings, the DAS cocrystal system has strong hydrogen bonding and stacking interactions. We also performed quantum chemical calculation and quantum theory of atoms in molecules (QTAIM) analysis to understand the strength of intermolecular interactions. From this study, we observed that cocrystallization was a promising technique for changing the physicochemical properties of DAS.

Geometrical and temperature impact on elucidation of intermolecular interactions for the binary mixtures of morpholine with aliphatic esters by thermodynamic, FTIR and DFT study

Abstract In this investigation, the binary solutions of morpholine (MP) with tert-butyl acetate (TBA), iso-butyl acetate (IBA), butyl acetate (BA) and butyl acrylate (BAC) were prepared for the densities (ρ) and speeds of sound (u) measurements at T = (303.15, 308.15, 313.15 and 318.15) K over the entire composition range and at atmospheric pressure (P = 0.1 MPa). From these data, excess thermodynamic properties such as excess molar volume ( V m E ${V}_{m}^{E}$ ), excess isentropic compressibility ( κ S E ${\kappa }_{S}^{E}$ ) and excess speeds of sound ( u E ${u}^{E}$ ) were calculated to elucidate the strength and types of intermolecular interactions between the component molecules. Redlich-Kister (RK) equation and Prigogine–Flory–Patterson (PFP) theory was applied to correlate the excess parameters and excess volumes, respectively. Further, intermolecular free length theory and collision frequency theory were used to correlate the speed of sound data. Shifting of bands (δν), bond length and hydrogen bond strength between the atoms were calculated from the experimental FTIR and DFT theoretical studies. The systematic increasing order of the intermolecular hydrogen bond strength between the two atoms in the studied binary systems as follows: TBA > IBA > BA > BAC.

Vibrational spectra and quantum chemical investigations on nicotinium nitrate monohydrate single crystal for anti bacterial studies

Nicotinium Nitrate Monohydrate (NNM) was grown by slow evaporation method. The arrangment of the molecules and hydrogen bonding intractionsin the grown crystal were analyzed using single crystal XRD. The structure, functional groups (vibrational analysis) and electronic properties (Mulliken and HOMO-LUMO analysis) were calculated by the density functional theory (DFT)/B3LYP/wB97XD method using 6–311++G (d,p) basis set. Also, the binding energy and the effect of basis set superposition error (BSSE) on the ring motifs have been investigated. The intermolecular interactions and charge delocalization density of NNM crystal have been analyzed using NBO 3.1 program. The strength of intermolecular interaction was further analyzed by 3D Hirshfeld surface analysis using fingerprint plot. Improved solubility of the title crystal NNM shows an enhanced physio-chemical activity compared to pure vitamin B3 (Nicotinic acid). The antibacterial activity of NNM crystal increased against Staphylococcus aureus a gram-positive bacteria when compared with pure nicotinic acid.

Chaos in coupled atom–molecular Bose–Einstein condensates

We investigate the chaotic dynamics of a coupled three-level atom–molecular Bose–Einstein condensate system composed by one molecular mode and two atomic modes. With the increase of atom–molecular coupling strength, we reveal the emergence of chaotic oscillations of the relative population difference between two atomic modes, which can be proven by the broad windows with a huge number of frequencies in spectral density and the chaotic trajectories in phase space diagrams. The different effects of initial states on atomic population oscillations are revealed, where for more particles in the initial state of the molecular model, chaos appears in the larger parameter region of system dynamics. Furthermore, we find that strong intermolecular interaction strength can suppress chaos resulting from strong atom–molecule coupling. This is due to the difficult transformation between atomic and molecular modes, as well as the relatively independent dynamic evolution of atoms and molecules.

Experimental and theoretical analyses and investigation of intermolecular interactions and antibacterial activity of a novel proton transfer compound:8-hydroxyquinolinium oxalate monohydrate

A novel proton transfer compound, 8-hydroxyquinolinium oxalate monohydrate was synthesised by solid state grinding of 8-hydroxyquinoline and oxalic acid. The resulting compound is characterised by single crystal X-ray diffraction (SXRD), FT-IR, UV–Visible, TG/DTG, DTA and DSC analyses. The compound crystallizes in monoclinic crystal system with space group P21/n. The carboxylate oxygen O2 which acts as a tetrafurcated acceptor of four hydrogen bonds is the main feature of the crystal structure. The molecules are linked together by O–H⋯O, N–H⋯O and C–H⋯O hydrogen bonds. Carbonyl-carbonyl interactions play a crucial role in stabilising the crystal packing. Hirshfeld surface analysis and the associated finger print plots facilitates the comparison of intermolecular interactions. The nature of charge density distribution and topological parameters of the proton transfer region N1–H1A⋯O2 hydrogen bond reveals that the bond has considerable covalent character. Natural Bond Orbital (NBO) has been extended to analyse the nature and strength of intermolecular interactions. Topology analysis using ELF and LOL reveals electron localisation and depletion regions. ADMET analysis reveals that the compound satisfies Lipinski’s rule of five and drug likeness. Antibacterial activity was screened against 3 g positive - Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus and 2 g negative strains- Klebsiella pneumonia and Salmonella typhi by employing disc diffusion method.

Control of the Crystal Morphology and Polymorphic Form of a Dithiadiazolyl Radical Using Co-sublimation

Crystals of the elusive α-polymorph of the dithiadiazolyl radical p-NCC6F4CNSSN• (1) have been isolated from co-sublimations of 1 with a second radical, 2,6-C6H4F2CNSSN• (2). Co-sublimation of 1 and 2 also results in control of the morphology of crystals of the β-polymorph of 1, yielding blocks of 1β instead of the long needles more commonly obtained. An analysis of the intermolecular interaction strengths in the two polymorphs gives insight into a proposed mechanism for polymorph control.

Unraveling the Nature and Strength of Non-covalent Interactions on the Surface of Fullerenes.

The nature and strength of the noncovalent intermolecular interactions on the surface of fullerenes must be understood for the application of these molecules in pharmaceuticals and materials chemistry. Consequently, experimental and theoretical evaluations of such weak interactions have been conducted in parallel. Nevertheless, the nature of these interactions remains a topic of ongoing debate. In this context, this concept article summarizes recent advances in experimental and theoretical efforts aimed at characterizing the nature and strength of non-covalent interactions on fullerene surfaces. Specifically, this article summarizes recent studies conducted on host-guest chemistry based on various macrocycles and on catalyst chemistry based on conjugated molecular catalysts composed of fullerenes and amines. In addition, conformational isomerism analyses performed using fullerene-based molecular torsion balances and state-of-the-art computational chemistry are reviewed. These studies have enabled a comprehensive evaluation of the contributions of electrostatic, dispersive, and polar interactions on the surface of fullerenes.

Molecular interaction studies in binary liquid mixtures containing ethyl acetate with n-octanol at different temperatures

Abstract: Experimental values of ultrasonic velocity (u), density (ρ) and viscosity () for the binary mixture Ethyl acetate (1) + n-Octanol (2) were measured over the whole composition range at temperature T = (295.15, 298.15,301.15 and 305.15) K and at the atmospheric pressure. From the experimental data excess sound velocity (uE), excess viscosity (), excess free volume ( and excess internal pressure (PiE) were calculated. These results have been fitted to the Redlich-Kister polynomial equation. Excess viscosity (), excess free volume ( and excess internal pressure (PiE) were found to be negative for all temperatures. Excess sound velocity (uE), excess viscosity (), excess free volume ( and excess internal pressure (PiE) were plotted against the mole fraction of ethyl acetate over the whole composition range at 295.15, 298.15, 301.15 and 305.15 K. They have been analysed to discuss the nature and strength of intermolecular interactions in these mixtures.

Biomolecular condensate growth inside nucleus is regulated by the interplay of the intermolecular interaction strength and local chromatin density.

Biomolecular condensate growth inside nucleus is regulated by the interplay of the intermolecular interaction strength and local chromatin density.

Role of halogen atoms in the mechanical properties of para-substituted benzaldehyde oximes

The mechanical properties of 4-halogen-substituted benzaldehyde oxime crystals depend upon the halogen atom providing different strengths of intermolecular interactions.

Gold(III) derivatives as the noncovalent interaction donors: theoretical study of the π-hole regium bonds.

Except for the well-known σ-hole regium bonds formed by metal nanoparticles and M(I) (M = Cu, Ag, and Au) derivatives, the existence of π-hole regions located above and below the Au atom in gold(III) derivatives suggests that gold(III) also functions as an efficient electrophilic site. In this study, a comprehensive analysis was conducted on the electrophilicity of trichloro-(p-toluonitrilo-N)-gold(III) derivatives AuL3(NCC6H4X) (L = Cl, Br, CN; X = NH2, CH3, CF3, NC, and CN) and the nature of π-hole regium bonds in the AuL3(NCC6H4X)⋯LB (LB = NH3, N(NH3)3, CH2O, C2H2, C2H4, C6H6) and (AuCl3(NCC6H4Y))n (Y = Cl, CN, NC, NO2; n = 2, 3)) complexes. The characteristics of the π-hole regium bonds were studied with respect to the influence of ligands and substituents, the strength of intermolecular interactions between Au(III) derivatives and Lewis bases, and those in the polymers. In the case of the AuL3(NCC6H4X)⋯NH3 complexes, the strength of the regium bonds increases gradually in the order of L = Cl < Br < CN and X = NH2 < CH3 < CF3 ≈ NC < CN. The ligands (L) attached to the Au atom exert a significant effect on the strength of the π-hole regium bonds in comparison to the substituents (X) on the benzene ring. The regium bonds are primarily dominated by electrostatic interaction, accompanied by moderate contribution from polarization. Linear relationships were identified between the electrostatic energies and the local most positive potentials over the Au atom, as well as between the polarization energies and the amount of charge transfer. Most of the π-hole regium bonds in the AuL3(NCC6H4X)⋯LB complexes exhibit the characters of closed shell noncovalent interactions. In the polymers (AuCl3(NCC6H4Y))n, weak face-to-face π-π stacking interactions are also present, in addition to regium bonds. The trimers displayed a slightly negative cooperativity in comparison to the dimers.

Spin-orbit coupling in molecular complexes beyond van der Waals regime: Key factors for further splitting of 2P3/2 ground state

We report a joint spectroscopic and theoretical study probing spin-orbit coupling (SOC) in a variety of molecular complexes between an iodine atom and a ligand (L) with L ranging from Ar, HF to formic/acetic acids, and glycine/N-methylated glycine derivatives. Cryogenic photoelectron spectroscopy of L·I- (L=HCOOH, CH3COOH) reveals three distinct peaks, identified as three SOC states, denoted as X(1/2), A(3/2), and B(l/2) for the corresponding neutrals. The X and A separation ΔEXA is measured to be 0.10 eV for both, whereas the X and B gap ΔEXB is 0.98 and 0.97 eV for formic and acetic acid, respectively. These new ΔEXA values are compared with the previously reported values for the molecular complexes L·I· with L=Ar, HF, glycine, and A-methylated glycines. All together these complexes encompass a diversity of intermolecular interactions, from van der Waals to weak and strong hydrogen bonding. While the ΔEXB remains similar, the ΔEXA is shown to be extremely sensitive to the type of ligands and interactions, spanning from 5 meV to 150 meV. High-level relativistic quantum calculations including explicit SOC formulism nicely reproduce all experimental SOC splitting. A direct correlation between the magnitude of ΔEXA with the intermolecular interaction strength or bond distance of the neutral complexes—the stronger interaction (shorter bond length), the greater splitting, is established.

Synthesis, structural and theoretical investigations on 3-diethyl 2-({4-[3-ethoxy-2-(ethoxycarbonyl)-3-oxo-2-phenylpropyl]-2,5-dimethylphenyl}methyl)-2-phenylpropanedioate

Because bioactive ester derivatives are important pharmacophores, the current study focuses on the synthesis and evaluation of their pharmacological activity. In this case, novel 1,3-diethyl 2-(4-[3-ethoxy-2-(ethoxycarbonyl)-3-oxo-2-phenylpropyl]-2,5-dimethylphenylmethyl)-2-phenylpropanedioate (C36H42O8) was synthesized in good yield. Elemental analysis, mass spectroscopy, FT-IR and NMR spectroscopy are used to analyse the compound. The X-ray diffraction examination of a single crystal indicates that the molecular structure crystallises in the monoclinic space group P21/n, with half of the molecule being crystallographically unique (Z' = 0.5) with Z = 2. Surprisingly, the inversion centre is located at the centre of the methyl-substituted benzene ring, which generates the entire molecule via symmetry operation. Crystallographic and computational chemistry technologies are used to examine the nature and strength of intermolecular interactions amongst inversion-related dimers (Hirshfeld surface, energy framework, QTAIM and NCI analysis). Koopman's approximation was used to calculate the frontier molecular orbitals, HOMO-LUMO energy gap, and associated reactive parameters. Furthermore, molecular docking experiments demonstrated the compound with Antieczematic proteins as well as protein-ligand interactions, hydrogen bond interactions are delibrated.

Periodic Density Functional Theory Calculations of Uranyl Tetrachloride Compounds Engaged in Uranyl-Cation and Uranyl-Hydrogen Interactions: Electronic Structure, Vibrational, and Thermodynamic Analyses.

Solid-state uranyl hybrid structures are often formed through unique intermolecular interactions occurring between a molecular uranyl anion and a charge-balancing cation. In this work, solid-state structures of the uranyl tetrachloride anion engaged in uranyl-cation and uranyl-hydrogen interactions were studied using density functional theory (DFT). As most first-principles methods used for systems of this type focus primarily on the molecular structure, we present an extensive benchmarking study to understand the methods needed to accurately model the geometric properties of these systems. From there, the electronic and vibrational structures of the compounds were investigated through projected density of states and phonon analysis and compared to the experiment. Lastly, we present a DFT + thermodynamics approach to calculate the formation enthalpies (ΔHf) of these systems to directly relate to experimental values. Through this methodology, we were able to accurately capture trends observed in experimental results and saw good quantitative agreement in predicted ΔHf compared to the value calculated through referencing each structure to its standard state. Overall, results from this work will be used for future combined experimental and computational studies on both uranyl and neptunyl hybrid structures to delineate how varying intermolecular interaction strengths relates to the overall values of ΔHf.

Pressure, directional dependent mechanical anisotropies and phase transition studies of β-5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO) and 2,4,6-triamino-1,3,5-trinitrobenzene (TATB)

This work highlights the effect of pressure ranging from 0 to 9 GPa on structural, directional dependent mechanical properties and unravel the previously unknown phase transitions of two important high energy molecular solids namely monoclinic-β-Nitrotriazole (NTO) and 2,4,6-triamino-1,3,5-trinitrobenzene (TATB). The projected augmented plane wave method with generalized gradient approximation Perdew–Burke–Ernzerhof functional with the D2 van der Waals corrections method of Grimme is used to reproduce the experimental data within ∼1% error. The structural optimization results reveal that β-NTO undergoes a previously unknown structural phase transition at 9 GPa which is evident from the abrupt change of calculated lattice vectors, volume (V), lattice angle β at 9 GPa. The single crystal elastic properties analysis also supports these findings and NTO voilate the Born’s mechanical stability criteria at 9 GPa. Besides to it, all the calculated volumetric and directional dependent shear modulus (G), bulk modulus (B), compressibility results of β-NTO in (100), (010), (001) planes also suggest a possible phase transition around 9 GPa. The directional dependent polycrystalline compressibility anisotropy analysis of TATB with pressure in (100), (010), (001) planes unreveal the origin of experimentally reported new phase transition around 4 GPa. The calculated Pugh B/G ratio suggests that, both the materials found to be brittle in the studied pressure range except NTO at 9 GPa. The degree of mechanical anisotropy of β-NTO found to increase with increasing pressure from (100)–(010)–(001) planes, while the TATB anisotropy results were found to be relatively small and stable. The Young’s modulus (E), Poisson’s ratio (σ), P-wave modulus, universal elastic anisotropy (A ), Chung-Buessen anisotropy (A ), Vickers hardness coefficient (H ), sound velocities ((V ) average, (V ) longitudinal, (V ) transverse) and (θ D ) Debye temperature are also predicted. The calculated intermolecular interaction strength contribution to the total Hirsh Field Surface at different pressures confirms the initial decomposition mechanism of NTO, TATB and the results are good in agreement with previous observations. Thus our work has accentuated the reasons behind the impact and friction sensitivity differences of β-NTO, TATB through the two new phase transitions.

B- and Al-Doped Porous 2D Covalent Organic Frameworks as Nanocarriers for Biguanides and Metformin Drugs.

Nanostructures such as nanosheets, nanotubes, nanocages, and fullerenes have been extensively studied as potential candidates in various fields since the advancement of nanoscience. Herein, the interaction between biguanides (BGN) and metformin (MET) on the modified covalent organic framework (COF), COF-B, and COF-Al was investigated using density functional theory at the ωB97XD/6-311+G (d, p) level of computation to explore a new drug delivery system. The electronic properties evaluation reveals that the studied surfaces are suited for the delivery of both drug molecules. The calculated adsorption energies and basis set superposition errors (BSSE) ranged between -21.20 and -65.86 kJ/mol. The negative values obtained are an indication of excellent interaction between the drug molecules and the COF surfaces. Moreover, BGN is better adsorbed on COF-B with Eads of -65.86 kJ/mol, while MET is better adsorbed on COF-Al with Eads = -47.30 kJ/mol. The analysis of the quantum theory of atom in molecules (QTAIM) explained the nature and strength of intermolecular interaction existing between the drug molecules BGN and MET with the adsorbing surfaces. The analysis of noncovalent interaction (NCI) shows a weak hydrogen-bond interaction. Other properties such as quantum chemical descriptors and natural bond orbital (NBO) analysis also agree with the potential of COF surfaces as drug delivery systems. The electron localization function (ELF) is discussed, and it confirms the transitions occurring in the NBO analysis of the complexes. In conclusion, COF-B and COF-Al are suitable candidates for the effective delivery of BGN and MET.

Modulating Aggregation in Microemulsions: The Dispersion by Competitive Intermolecular Interaction Model.

A phenomenological model has been developed for the mechanism of action of phase modifiers as additives that control aggregation phenomena within water-in-oil emulsions. The "Dispersion by Competitive Intermolecular Interaction" model (DCI) explicitly considers the strength and prevalence of different intermolecular interactions that influence the molecular association of amphiphiles, the resulting distribution of aggregate size, and interaggregate interactions that influence phase phenomena. The existing "cosolvent" and "cosurfactant" association models, which describe the distribution of these amphiphiles within the solution, are re-examined in the context of intermolecular interactions. The different contributions of intermolecular interactions to the potential energy landscape of molecular association create distinct regimes within the DCI model that explain prior observations of cosolvent and cosurfactant behavior. The specific system under consideration, the N,N,N',N'-tetraoctyl diglycolamide amphiphile extractant with tributyl phosphate or dihexyl octanamide phase modifier additives, represents a new regime-labeled the polar disruption regime-where strong hydrogen bonding of the phase modifier with the polar-solutes disrupts the internal hydrogen bonding network of the polar micellar core, thereby decreasing aggregate size and narrowing the polydispersity in solution.

Hydrogen bond network reconstruction of lignite for efficient moisture removal via deep-eutectic-solvent-assisted hydrothermal treatment

The hydrogen bond formed between water molecules and oxygen functional groups was an important factor for the moisture content of lignite. Deep eutectic solvent (DES, synthesized at a molar ratio of 1: 2 by ChCl and ZnCl2) with abundant hydrogen bond acceptors and donors was employed to facilitate the removal of moisture in lignite under hydrothermal treatment (HT) condition. At the same upgrading temperature, the dehydration efficiency of lignite upgraded by DES-assisted HT (DES-HT) was higher than HT method. The dehydration efficiency of DES-HT method was increased from 63.99 % (HT) to 68.03 % as the moisture content of upgraded lignite decreased from 8.02 % (HT) to 7.12 % (DES-HT) at 300 °C. Meanwhile, dehydration efficiency of molecular water was increased from 61.34 % (HT) to 66.06 % since the molecular water content of upgraded lignite decreased from 1.79 % (HT) to 1.57 % (DES-HT). In addition, the contents of free water and capillary water in lignite which was upgraded by DES-HT were also lower than those in lignite upgraded by HT. Characterization of upgraded coal via elemental analysis and X-ray photoelectron spectroscopy revealed that DES could weaken the stability of oxygen functional groups and thus promote the decomposition of hydrophilic functional groups such as C-OH/COC and OC-OH. Density functional theory calculations identified that DES could reconstruct the hydrogen bond network with moisture and weaken the intermolecular interaction strength between oxygen functional groups and water molecules during HT process. As a result, both total moisture content and molecular water content of lignite could be removed more effectively by DES-HT.

Planarity is one of the essential requirements for fluorescence in Red Fluorescent Protein chromophore analogs

Synthesis and photophysical properties of four red fluorescent protein (RFP) chromophore analogs are reported. The analogs in crystals are held by different non-covalent intermolecular interactions such as C–H....O hydrogen bonding, C–H....π, π....π, and halogen bonding interactions, stabilizing the molecular stacks. The carbonyl group in the imidazol-5(4H)-one ring generates diverse packing systems in the compound via intermolecular C–H....O hydrogen bonds. Compounds 1 and 2 adopt a non-planar geometry, while 3 and 4 are slightly bent. Compound 3 shows a donor-acceptor type of π-π interactions resulting in a lateral offset stacking that is stabilized by strong π-π stacking between the imidazolin-5-one ring and methoxy substituted benzene, along with halogen....halogen bonding interactions. Compound 4 displays a strong π-π stacking between two imidazol-5(4H)-one rings. The Hirshfeld surfaces of two-dimensional fingerprint plots were used to analyze the strength of intermolecular interactions in the structures. The photoluminescence is also tuned in these molecules by appropriate substitution. Thus, the azine compounds are completely non-fluorescent compared to the other two.

Quantitative analysis of intermolecular interactions in crystalline substituted triazoles

This manuscript comprehensively examines four triazole derivatives using Hirshfeld surface and fingerprint analysis, PIXEL energy for molecular pairs, lattice energies for crystal packing, atoms-in-molecules (AIM) topological analysis, and noncovalent interaction (NCI) plots for intermolecular interactions. The fingerprint plots of the Hirshfeld surface analysis provide a quantitative picture of various substituent effects on the noncovalent interactions that contribute to the crystal packing stabilization of these four structures (TN1–TN4). The PIXEL method provides the intermolecular interaction energies for the molecular dimers observed in these structures. The nature and strength of intermolecular interactions at the (3, -1) bond critical point have been studied using the approach of atoms-in-molecules (AIM) via a topological analysis of the electron density distribution. The topology parameters suggested that the intermolecular interactions are classified as closed-shell interactions, and NCI plots were employed to identify the nature of the involved noncovalent interactions. Therefore, a detailed computational analysis renders insights into the electronic characteristics of different noncovalent interactions in the solid state of the structures in the current investigation.