Interactions Of Aromatic Rings Research Articles

Investigation of Chrysene heterodimers complexes potential energy surface using ab initio computational methods

Numerous chemical and biological entities are greatly impacted by non-covalent interactions in terms of their stability and structure. One such example is the interaction of aromatic rings. These interactions are highly valued in the domains of astrochemistry, biology, chemistry, biochemistry, and material science. The main goals of this study are to explore the Potential Energy Surface (PES) of Chrysene (Chy) heterodimers, identify the most stable configurations among the Chy-Bz, Chy-Np, and Chy-Anth heterodimer complexes, and analyze the inter-molecular interactions between these molecules. This analysis was conducted utilizing ab initio computational techniques. On their PES, the Chy-Np heterodimer exhibited four minima, while the Chy-Bz and Chy-Anth heterodimer complexes showed three. Compared to conformers oriented perpendicularly, co-facial arrangement conformers in Chy heterodimer complexes have stable structures. The global minimum structure of Chy-Bz has been determined to be the face isomer, while Chy-Np and Chy-Anth have global minimum structures of the cross isomer. The binding energies of the structures generated by MP2 are higher than those of DFT-D3, DFT-D4, and SCS-MP2. Optimized geometries and binding energies of larger hydrocarbon aromatic systems are explained in detail by B3LYP-D3 and the recently created B3LYP-D4.

Surface methodology for optimized adsorption of hazardous organic pollutant from aqueous solutions via novel magnetic metal organic framework: Kinetics, isotherm study, and DFT calculations

An efficient way to remove Janus Green B (JGB) dye from contaminated water sources is using of magnetic cerium (III) metal–organic framework (MCe-MOF). Analytical methods such as PXRD, TEM, FESEM, FT-IR, PZC, and XPS were used in the characterization of the MCe-MOF microspheres in order to assess the phase, crystallinity, shape, surface characteristics, and chemical composition of the MCe-MOF material. Impressive physical characteristics of the synthesized MCe-MOF material included a high surface area of 1340.05 m2/g. Conversely, MCe-MOF’s magnetic saturation (MS) was measured at 36.47 emu.g−1. The purpose of the study was to determine if MCe-MOF could effectively remove JGB dye from wastewater by adsorption. Adsorption settings that were studied included pH, adsorbent dose, beginning dye concentration, contact time, and temperature. The JGB electrical characteristics, reactivity, and shape were ascertained through the application of density functional theory (DFT). The placement of electrophilic and nucleophilic attack sites is in good agreement with the molecular orbitals (HOMO and LUMO) and MEP results, according to DFT. Based on the findings, MCe-MOF had a high capacity for adsorbing JGB dye, with an adsorption data fit by pseudo-second-order kinetic models and the Langmuir isotherm. It was evident from the adsorption energy of 27.8 kJ.mol−1 that chemisorption was the mode of adsorption. The optimal conditions for attaining a high adsorption capacity were found to be pH 8 and 0.02 g of MCe-MOF dose. The adsorption process of JGB dye onto MCe-MOF was seen to be spontaneous, endothermic, and random, as indicated by the temperature-dependent increases in the thermodynamic parameters ΔGo, ΔHo, and ΔSo. The adsorption process was optimized through the application of Response Surface Methodology and Box-Behnken design (RSM, BBD). The successful removal of dyes from the MCe-MOF material was made possible by these methods. While π-π bonding happens through the interaction of aromatic rings, chemisorption entails the formation of chemical interactions between the adsorbate and adsorbent. Electrostatic interactions arise from the attraction or repulsion of charges between the adsorbate and adsorbent, and pore-filling happens when the adsorbate fills the adsorbent’s pores. For the removal of JGB dye from wastewater, MCe-MOF exhibits great potential as an adsorbent because of its numerous adsorption processes and high adsorption capacity.

Synthesis, Structural Characterization, and Hirschfeld Surface Analysis of a New Cu(II) Complex and Its Role in Photocatalytic CO2 Reduction.

A new Cu(II) complex, [CuL1L2(CH3COO)2(H2O)]·H2O, was synthesized by the reaction of Cu(CH3COO)2·H2O, 6-phenylpyridine-2-carboxylic acid (HL1), and 4-[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]pyridine (L2) in ethanol-water (v:v = 1:1) solution. The Cu(II) complex was characterized using elemental analysis, IR, UV-vis, TG-DTA, and single-crystal X-ray analysis. The fluorescence properties of the copper complex were also evaluated. The structural analysis results show that the Cu(II) complex crystallizes in the triclinic system with space group P-1. The Cu(II) ion in the complex is five-coordinated with one O atom (O2) and one N atom (N1) from one 6-phenylpyridine-2-carboxylate ligand (L1), one N atom (N2) from 4-[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]pyridine ligand (L2), one O atom (O4) from acetate, and one O atom (O5) from a coordinated water molecule, and it adopts a distorted trigonal bipyramidal geometry. Cu(II) complex molecules form a two-dimensional layer structure through intramolecular and intermolecular O-H…O hydrogen bonding. The two-dimensional layer structures further form a three-dimensional network structure by π-π stacking interactions of aromatic rings. The analysis of the Hirschfeld surface of the Cu(II) complex shows that the H…H contacts made the most significant contribution (46.6%) to the Hirschfeld surface, followed by O…H/H…O, N…H/H…N and C…H/H…C contacts with contributions of 14.2%, 13.8%, and 10.2%, respectively. In addition, the photocatalytic CO2 reduction using Cu(II) complex as a catalyst is investigated under UV-vis light irradiation. The findings reveal that the main product is CO, with a yield of 10.34 μmol/g and a selectivity of 89.4% after three hours.

Fabrication, physicochemical characterization and theoretical studies of some new mixed ligands complexes based on N-(1H-benzimidazol-2-yl)-guanidine and 1, 10-phenanthroline: DNA interaction, biological applications and molecular docking approach

The fabrication and structural identification of mixed ligand chelates resulting from 1-(1H-benzimidazol-2-yl) guanidine (BIG = main ligand) and 1,10-Phenanthroline (phen) (secondary ligand). The tested compounds were investigated using TGA, CHN, spectra analysis (FT-IR, Mass spectra, NMR), melting point, magnetic moments, molar conductance, Ultraviolet–Visible spectroscopy as well computational studies. The conductance results showed that the tested Pd(II), VO(II) and Ag(I) chelates have electrolytes in fresh solutions of DMSO lies in the range 38.12–118.87 Ω−1 cm2 mol−1 except, Cu(II) chelate is a non-electrolyte it is value equal 15.16 Ω−1 cm2 mol−1. FT-IR spectrum displays that the tested main ligand is coordinated with metal ions in a bi-dentate behavior with N, N donor sites of the HN=C and C=N. While the second ligand coordinated with metal ions through its N2 atom in the pyridine ring. Moreover, the obtained analytical data regarding complexation in solution, molar ratio and continuous variation methods suggest 1M: 1 L molar ratio. Also the stability constant of tested complexes was identified in solution state and the formation constants (Kf) were evaluated by applying continuous-variation method. Stability of complexes was arranged by BIGPAg > BIGPVO > BIGPCu > BIGPPPd in agreement with Kf values. The pH profile revealed that the wide range of pH stability of the tested complexes is at pH = 4- 10 in most of them. Magnetic and electronic spectra are applied to deduce the coordinating ability of the tested ligands and the geometric structure of the studied chelates. That data of magnetic susceptibility for ternary mixed chelates are locked to an octahedral geometry for Cu(II) & VO(II) chelates due to the data of (μeff = 1.8 and 1.83 B.M) respectively and Pd(II) and Ag(I) chelates are diamagnetic with square planar and tetrahedral geometry, respectively. The TGA study of these studied complexes displays that the hydrated H2O, acetate, nitrate, and acetylacetonate anions are removed in the first (45°C-180°C) and second degradation steps followed directly by degradation of the studied ligands in the following stages. The thermodynamic factors, like ΔS*, ΔH*, E*, A and ΔG* are evaluated from the TGA curves and explained. The DFT/B3LYP computation method was applied for the estimation of the MEP, (HUMO & LUMO) energy for the studied compounds. In-silico assay was executed by two different approaches over compounds to evaluate their biological behavior and degree of interaction with biological systems, before practical application. BIGPPd complex displayed priority in interaction with various protein. In-vitro assay was then carried out for compounds against different microbes and BIGPPd showed high antimicrobial activity with inhibition zones are established to be 45.75 ± 0.10 and 41.95 ± 0.05 mm against B. Cereus and G. Candidum at 25 µg/mL. Also, their cytotoxic behavior was examined against MCF-7, HepG2 and HCT-116 carcinoma cell lines, high cytotoxicity was clearly recorded with BIGPPd complex with IC50% are established to be (5, 6.25 and 7.14 µg/mL) respectively. Furthermore, antioxidant activity was examined, and the complexes exhibited high reactivity with trapping free radicals. The BIGPPd exhibited significant free radical scavenging activity with an IC50 value of 20.15 μg/ml. The interaction of metal chelates with DNA was detected by gel electrophoreses, viscosity and spectral studies. Spectrophotometric titration and viscosity studies expose that each of tested complex is an avid binder to DNA. The intrinsic binding constants were calculated for all the tested compounds could bind to Ct-DNA generally through replacement, intercalative mode & minor groove binding of interactions with the sequence: BIGPVO (6.05×104) > BIGPCu > BIGPPd> BIGPAg >BIG (1.16×103). This may be due to enhanced hydrophobic & electrostatic interaction of aromatic rings. Finally, such complexes may be considered as a promising bioactive agent.

Identification of the myxobacterial secondary metabolites Aurachin A and Soraphinol A as promising inhibitors of thymidylate kinase of the Monkeypox virus.

Thymidylate kinase (TMPK) of monkeypox virus (MPXV) has emerged as a promising target for potential therapeutics due to its significant role in pyrimidine metabolism. While smallpox drugs are advised for treating monkeypox, the European Medicine Agency has sanctioned Tecovirimat due to its potent nanomolar activity. Nonetheless, there is a need for monkeypox-specific therapeutic options. In this work, we employed docking-based virtual screening and molecular dynamics (MD) simulations to identify myxobacterial secondary metabolites as promising anti-viral natural compounds capable of inhibiting thymidylate kinase. The computational pharmacokinetics and manual curation of top-scoring compounds identified six lead compounds that were compared in terms of protein-ligand contacts and protein-essential dynamics. The study shows that among the six candidates, Aurachin A and the Soraphinol analogues such as Soraphinol A and Soraphinol C remain very stable compared to other compounds, enabling the active site integrity via a stable dynamics pattern. We also show that other compounds such as Phenoxan, Phenylnannolone C, and 8E-Aurafuron B remain unstable and have a negative impact on the active site integrity and may not be suitable binders for TMPK protein. Analyzing the Aurachin A and Soraphinol A binding, the established hydrogen bonds with Arg93 and the conserved hydrophobic interaction with Tyr101 are consistent with previous experimental interactions. Additionally, a deeper insight into the indole and the aromatic ring interaction through π-π stacking and π-cation interactions, as well as the background of Aurachin A and Soraphinol A as a bioactive compound, has significant implications not only for its potential as a promising drug but also for directing future drug discovery efforts targeting the TMPK protein.

Synthesis and Thermal Studies of Two Phosphonium Tetrahydroxidohexaoxidopentaborate(1-) Salts: Single-Crystal XRD Characterization of [iPrPPh3][B5O6(OH)4]·3.5H2O and [MePPh3][B5O6(OH)4]·B(OH)3·0.5H2O.

Two substituted phosphonium tetrahydoxidohexaoxidopentaborate(1-) salts, [iPrPPh3][B5O6(OH)4]·3.5H2O (1) and [MePPh3][B5O6(OH)4]·B(OH)3·0.5H2O (2), were prepared by templated self-assembly processes with good yields by crystallization from basic methanolic aqueous solutions primed with B(OH)3 and the appropriate phosphonium cation. Salts 1 and 2 were characterized by spectroscopic (NMR and IR) and thermal (TGA/DSC) analysis. Salts 1 and 2 were thermally decomposed in air at 800 °C to glassy solids via the anhydrous phosphonium polyborates that are formed at lower temperatures (<300 °C). BET analysis of the anhydrous and pyrolysed materials indicated they were non-porous with surface areas of 0.2-2.75 m2/g. Rhe recrystallization of 1 and 2 from aqueous solution afforded crystals suitable for single-crystal XRD analyses. The structure of 1 comprises alternating cationic/anionic layers with the H2O/pentaborate(1-) planes held together by H-bonds. The cationic planes have offset face-to-face (off) and vertex-to-face (vf) aromatic ring interactions with the iPr groups oriented towards the pentaborate(1-)/H2O layers. The anionic lattice in 2 is expanded by the inclusion of B(OH)3 molecules to accommodate the large cations; this results in the formation of a stacked pentaborate(1-)/B(OH)3 structure with channels occupied by the cations. The cations within the channels have vf, ef (edge-to-face), and off phenyl embraces. Both H-bonding and phenyl embrace interactions are important in stabilizing these two solid-state structures.

The kinetics of aggregation of the Aβ1-40 peptide monitored by magnetooptical methods

Protein misfolding leads to the formation of amyloid fibrils, which presence is characterized for many serious diseases affecting millions of people worldwide. In the presented study we used, for the first time, magnetooptical (MO) methods such as Faraday and Cotton-Mouton effects (FE and CME respectively) to monitor the aggregation processes of one of the most studied peptides, amyloid β1-40 (Aβ1-40) which is associated with Alzheimer’s disease. Through the anisotropy of optical polarizability and magnetic susceptibility, CME is very sensitive to the shape of the studied species, which allows us to monitor their changes. The impact of incubation time (up to 40 days) and temperature (8, 23, 36 °C) on the aggregation of Aβ1-40 was evaluated by the measured coefficients that describe both effects. CME is found more suitable for monitoring protein aggregation than FE. Formation of Aβ1-40 fibrils and kinetic profile was also confirmed using the Thioflavin T fluorescence assay. Furthermore, CME was successfully used to demonstrate the self-assembly of phenylalanine, which is recognized as the crucial amino acid in the aggregation process of Aβ1-40. Our observations demonstrate the possible role of π-π interaction of aromatic rings in the self-assembly of amyloid fibrils.

Crystal structures of the sulfones of 2,3-diphenyl-2,3-di-hydro-4H-1,3-benzo-thia-zin-4-one and 2,3-diphenyl-2,3-di-hydro-4H-pyrido[3,2-e][1,3]thia-zin-4-one.

The title sulfones, 2,3-diphenyl-2,3-di-hydro-4H-1,3-benzo-thia-zine-1,1,4-trione, C20H15NO3S, and 2,3-diphenyl-2,3-di-hydro-4H-pyrido[3,2-e][1,3]thia-zine-1,1,4-trione, C19H14N2O3S, crystallize in space group P21/n with two mol-ecules in each of the asymmetric units and have almost identical unit cells and extended structures. In both structures, the thia-zine rings exhibit a screw-boat pucker. The inter-molecular inter-actions observed are C-H⋯O-type hydrogen bonds and parallel partial π-π stacking between the fused aromatic rings (benzo- or pyrido-) of the core of the mol-ecules within each asymmetric unit, and also connecting to mol-ecules with translational periodicity in the a-axis direction in what can be described as columns (two per asymmetric unit) of stacked mol-ecules with alternating chirality. The pendant phenyl groups of both mol-ecules do not participate in aromatic ring inter-actions.

Lignin nanoparticle-decorated nanocellulose cryogels as adsorbents for pharmaceutical pollutants

Adsorption is a relatively simple wastewater treatment method that has the potential to mitigate the impacts of pharmaceutical pollution. This requires the development of reusable adsorbents that can simultaneously remove pharmaceuticals of varying chemical structure and properties. Here, the adsorption potential of nanostructured wood-based adsorbents towards different pharmaceuticals in a multi-component system was investigated. The adsorbents in the form of macroporous cryogels were prepared by anchoring lignin nanoparticles (LNPs) to the nanocellulose network via electrostatic attraction. The naturally anionic LNPs were anchored to cationic cellulose nanofibrils (cCNF) and the cationic LNPs (cLNPs) were combined with anionic TEMPO-oxidized CNF (TCNF), producing two sets of nanocellulose-based cryogels that also differed in their overall surface charge density. The cryogels, prepared by freeze-drying, showed layered cellulosic sheets randomly decorated with spherical lignin on the surface. They exhibited varying selectivity and efficiency in removing pharmaceuticals with differing aromaticity, polarity and ionic characters. Their adsorption potential was also affected by the type (unmodified or cationic), amount and morphology of the lignin nanomaterials, as well as the pH of the pharmaceutical solution.Overall, the findings revealed that LNPs or cLNPs can act as functionalizing and crosslinking agents to nanocellulose-based cryogels. Despite the decrease in the overall positive surface charge, the addition of LNPs to the cCNF-based cryogels showed enhanced adsorption, not only towards the anionic aromatic pharmaceutical diclofenac but also towards the aromatic cationic metoprolol (MPL) and tramadol (TRA) and neutral aromatic carbamazepine. The addition of cLNPs to TCNF-based cryogels improved the adsorption of MPL and TRA despite the decrease in the net negative surface charge. The improved adsorption was attributed to modes of removal other than electrostatic attraction, and they could be π-π aromatic ring or hydrophobic interactions brought by the addition of LNPs or cLNPs. However, significant improvement was only found if the ratio of LNPs or cLNPs to nanocellulose was 0.6:1 or higher and with spherical lignin nanomaterials. As crosslinking agents, the LNPs or cLNPs affected the rheological behavior of the gels, and increased the firmness and decreased the water holding capacity of the corresponding cryogels. The resistance of the cryogels towards disintegration with exposure to water also improved with crosslinking, which eventually enabled the cryogels, especially the TCNF-based one, to be regenerated and reused for five cycles of adsorption-desorption experiment for the model pharmaceutical MPL. Thus, this study opened new opportunities to utilize LNPs in providing nanocellulose-based adsorbents with additional functional groups, which were otherwise often achieved by rigorous chemical modifications, at the same time, crosslinking the nanocellulose network.

A comprehensive review on the nature and synthetic organic compounds as corrosion inhibitors

Although corrosion is an inevitable part of daily life, it is always kept under control due to its technical, financial, and aesthetic significance. Erosion is a gradual phenomenon stimulated by anxiety about energy. Defense against corrosive environments on metals is inhibition. One of the most common and financially viable methods of preventing corrosion in metallic materials is the use of corrosion inhibitors (CIs). One of the five ways to prevent material corrosion, along with material selection, design, cathodic protection, and coating, is to use organic CIs. Particles with an unoccupied orbit on a metal substrate depend on adsorption values on the steel surface through the interactions of heteroatoms (N, O2, P, S), heterocyclic and aromatic rings, and conjugated double bonds. Through these interactions, molecules are attracted to the metal surface, where they bind and form an inhibitory barrier. This reduces the metal's corrosion rates as well as improves inhibition effectiveness. This review included a presentation of the CI compound's history before moving on to a discussion of how inhibition efficiency is affected by structure, substitution, heteroatoms, and molecular chain length. Weight loss (WL), electrochemical impedance spectroscopy (EIS), and dynamic active polarization techniques are used in a comparative investigation of the inhibitory performance of corrosion-inhibited compounds. Adsorption isothermal concepts and blocking processes. This paper discusses corrosion processes and scaling, various experimental corrosion techniques, the relationship between anticorrosion structure and effectiveness, and the process of novel inhibitors.

Robust immobilization of Au nanoparticles on snowflake structured covalent organic frameworks for highly shape-selective catalysis of cyclization reaction

Isoflavones, which are secondary metabolites, mostly possess potential in antioncogenic, cardiovascular action and antioxidant, etc. However, at present, the direct extraction of isoflavones from plants using enzymatic reaction is not only limited in source, but also low in efficiency. Therefore, it is a challenge to prepare isoflavones efficiently from easily available raw materials by chemical catalysis. In this work, a smart strategy of “amino acid regulated snowflake-structured covalent organic frameworks as alternative catalytic support” is proposed, which can control the pore size and disperse Au nanoparticles (NPs) by strong coordination between Au NPs and amino side chains. Importantly, it is interesting that the catalyst has good synergistic effects with shape-selective catalysis (99% vs 7%), pi-pi interaction of aromatic rings and excellent spatial confinement effect (20 Å vs 16 Å) during cyclization reaction using Au@COFs-01. In additon, the turnover frequency (TOF) can be enhanced to 530 h−1. Moreover, Au@COFs-01 can be easily regenerated for five cycles. The reaction mechanism and structure–activity relationship can be proposed by experimental and theoretical calculations. This method of constructing biomimetic COFs with biomass materials provides the basis for the application and design of novel COFs.

Synthesis, characterization and biocompatibility of guar gum-benzoic acid

A novel chemical functionalization of guar gum (GG) by benzoic acid (BA) via nucleophilic substitution reaction in aqueous solution has been reported. BA moieties are chosen due to coordination chemistry of carboxylic acid moieties, hydrophobicity and intermolecular interaction of aromatic rings. The presence of conjugated BA on guar gum-benzoic acid (GG-BA) with grafting density of 5.5% is confirmed by 1H NMR. Amorphous GG-BA with irregular morphology has been studied by UV–Vis, FTIR, XRD, SEM, TEM, TGA, computational chemistry and contact angle measurement. GG-BA in a concentration range from 0 to 4000 μg mL−1 has good biocompatibility to mouse embryonic fibroblasts (MEF), human mammary epithelial cells (MCF-10A) after 48 and 72 h of treatment using WST-1 assay. GG-BA shows great potential for the development of biomaterials such as bioadhesives, hydrogels, and coacervates.

Synthesis and crystal structure of racemic (R*,R*)-2,2'-(1,4-phenyl-ene)bis-(3-phenyl-2,3,5,6-tetra-hydro-4H-1,3-thia-zin-4-one).

In the racemic title compound, C26H24N2O2S2, one of the thia-zine rings shows a twisted boat conformation (Q = 0.743 Å, θ = 92.1°) and the other a half-chair puckering (Q = 0.669 Å, θ = 54.3°). The terminal phenyl rings are almost parallel to each other [dihedral angle 21.71 (10)°]. Both of these rings are orthogonal to the central phenyl ring, subtending a dihedral angle of about 78° in each case. The extended structure is consolidated by C-H⋯O and C-H⋯S hydrogen bonds as well as aromatic ring inter-actions of parallel-displaced and T-type. The mol-ecule has approximate C2 local symmetry but this is not carried over to its three-dimensional structure or the inter-molecular inter-actions.

Bridging the Void: Halogen Bonding and Aromatic Interactions to Program Luminescence and Electronic Properties of π-Conjugated Materials in the Solid State

π-Conjugated materials are promising candidates for emerging organic optoelectronic devices empowered by molecular design. The unsolved challenges of predicting and controlling their packing as solids, central to their properties and performance, currently limits their practical application. As noncovalent interactions drive packing, control over such interactions are critical to bridging from chemical structure to functional properties. In molecular crystals, halogen bonding and interactions of aromatic rings have emerged as versatile tools for noncovalent control with tailored luminescence and electronic properties. Here, we describe how the interplay of these directional and tunable interactions can engineer properties, including stimuli-responsive behavior. Halogen bonding can provide robust designs for directing 2D molecular assembly, whereas the intentional interactions of aromatic rings can yield metastable, switchable packing modes, as well as programmed stacking between layers of chromophores. Examples, herein, demonstrate clear relationships between assembly by design and resulting solid-state properties, and strategies presented offer guidance for future designs of π-conjugated molecular materials using specific aromatic interactions and halogen bonding.

Supramolecular construction of a cyclobutane ring system with four different substituents in the solid state

Methods to form cyclobutane rings by an intermolecular [2 + 2] cross-photoreaction (CPR) with four different substituents are rare. These reactions are typically performed in the liquid phase, involve multiple steps, and generate product mixtures. Here, we report a CPR that generates a cyclobutane ring with four different aryl substituents. The CPR occurs quantitatively, without side products, and without a need for product purification. Generally, we demonstrate how face-to-face stacking interactions of aromatic rings can be exploited in the process of cocrystallization and the field of crystal engineering to stack and align unsymmetrical alkenes in CPRs to afford chiral cyclobutanes with up to four different aryl groups via binary cocrystals. Overall, we expect the process herein to be useful to generate chiral carbon scaffolds, which is important given the presence of four-membered carbocyclic rings as structural units in biological compounds and materials science.

Synthesis and characterization of Fe(III), Pd(II) and Cu(II)-thiazole complexes; DFT, pharmacophore modeling, in-vitro assay and DNA binding studies

New pharmacologically active complexes were prepared from Pd (II), Fe (III), and Cu (II)ions with 2-amino-6-oxo-3-(piperidinylamidino)-4-(4methoxyphenyl)-6,7-dihydro-pyrano[2,3-d]-5,7thiazol ligand (MPTP). The ligand acted as neutral bidentate with the metals via NH and NH2 groups. FT-IR spectra, CHN-analysis, TGA, UV–Vis, molar conductance and 1H &13C NMR spectra were used to characterize the new compounds. Also stability constant of MPTP-complexes was identified in solution and pH-profile indicates high stability of complexes. Computational study was implemented to extract significant features for MPTP and its complexes. In addition to, essential maps were demonstrated over formulated chk-file. In-silico assay was executed by two different approaches over compounds to evaluate their biological behavior and degree of interaction with biological systems, before practical application. MPTPPd complex displayed priority in interaction with amino acid residues and drug-like feature. In-vitro assay was then carried out for compounds against different microbes and MPTPPd and MPTPCu showed high antimicrobial activity. Also, their cytotoxic behavior was examined against MCF-7, HCT-116, and HepG2 carcinoma cell lines, high cytotoxicity was clearly recorded with MPTPPd and MPTPCu complexes. Furthermore, antioxidant activity was examined and the complexes exhibited high reactivity with trapping free radicals. The interaction of metal chelates with DNA was detected by gel electrophoreses, viscosity and spectral studies. Spectrophotometric titration and viscosity studies expose that each of tested complex is an avid binder to DNA. This may be due to enhanced hydrophobic & electrostatic interaction of aromatic rings. Finally, such complexes may be considered as a promising bioactive agents.

Interactions of aromatic rings in the crystal structures of hybrid polyoxometalates and Ru clusters

Computational analysis for π–π interaction energies of {(arene)Ru}2+ containing complexes and relative group 5 hybrid polyoxometalates reveals different frameworks. Some perspectives on πOF materials processing and crystal engineering were discussed.

An analysis of structural, spectroscopic, quantum chemical and in silico studies of ethyl 3-[(pyridin-2-yl)amino]propanoate: A potential thrombin inhibitor

In the present investigation, we report an analysis of the structural, spectroscopic characterization, reactivity parameters, topological studies, and molecular docking studies of the synthesized ethyl 3-[(pyridin-2-yl)amino]propanoate (abbreviated to EPYAPP), C10H14N2O2. The molecular and crystal structure was determined by using the single-crystal X-ray diffraction technique. The whole molecule is planar with r.m.s.d. of all the non-hydrogen atoms being 0.041(2) Å. Further, the dihedral angle between the planes of the aromatic ring and the side chain is 1.6(1)o. The crystal structure features a pair of N-H…N hydrogen-bonded dimers connected via two C-H...π (π electrons of the aromatic ring) interactions to form a two-dimensional zig-zag sheet propagating parallel to the bc plane. The qualitative and quantitative estimation of close contacts in the solid phase of the title compound was performed through the 3D-Hirshfeld surface analysis and 2D-finger print plots. The quantum chemical calculations of the EPYAPP compound were performed at DFT/B3LYP/6-311++G(d,p) method at the ground state in the gas phase. The detailed investigation of each vibrational wave number was carried out by using the VEDA4 package, and theoretical results showed an excellent mutual agreement with the experimental spectral data. The HOMO-LUMO orbital energy calculations, chemical reactivity descriptors, and natural bond orbital analysis were also performed. Prone reactive sites of the title compound have been identified by the molecular electrostatic surface potential and Fukui functions, which are mapped to the electron density surfaces. Hydrogen bond dissociation energies and bond dissociation energies for all other single bonds were further calculated for the EPYAPP molecule in order to examine the autoxidation mechanism and degradation properties. The title compound forms a stable complex with human alpha thrombin (PDB code: 1PPB) (binding energy -7.03 kcal/mol)) antagonist and could be a lead compound for developing new thrombin inhibitor or anti-thrombotic drugs.

Molecular dynamics simulations of a stacked $$\uppi $$-conjugated soft material: binding energy and preferential geometry for self-assembly

Understanding intermolecular interactions among supramolecular self-assembled organization and identifying the molecular structure relevant to the self-assembly are crucial for designing materials with desired functionalities. Interactions of aromatic rings in a peptide–perylenediimide conjugate (P-1) are investigated using dispersion-corrected density functional theory. The binding energies of fully optimized dimeric P-1 are calculated to identify the most stable conformation of the dimer. We show that the dispersion correction terms have significant contributions to the total energies of the dimers. The combined results from electronic structure calculations and molecular dynamics simulations demonstrate that the stacked dimer with negative inter-planar angle with clock-wise rotation has stronger binding energy than the dimer with positive inter-planar angle. The excess stability of the dimer with clock-wise rotation is attributed to the intra- and inter-molecular $$\uppi $$ – $$\uppi $$ stacking of the side aromatic rings of the dimer facilitated by formation of less number of hydrogen bonds. The stacked P-1 dimer with negative inter-planar angle and stronger binding energy is identified as the building block of a super structure with left-handed helical arrangements. Our calculations will build the first step towards understanding the molecular origin of the stability of a specific super structure of P-1 over the other, as obtained in the experiment relevant to material science and technology.

X-Ray Structure, DFT Study of p-Chlorobenzoic Acid, and the Effect of In Silico Molecular Docking on Tankyrase I Enzyme

p-Chlorbenzoic acid carries a 4-chloro position atom where it may be important in coordinated with and control certain biological parameters , it can inhibit the action of specific enzyme in organisms. X‑ray data collection gives information about the analysis of the covalent and the non-covalent interactions in 3D quantitatively. Recrystallization of p-chlorobenzoic acid was carried out to remove any impurities and to be prepared in pure crystal form. X-ray analytical technique studied the structure and geometrical parameters. The experimental data were compared with the calculated ones for the optimized structure obtained from density functional theory (DFT) studies. X-ray structure of p-chlorobenzoic acid is found in dimer form stabilized with intermolecular H-bond interaction. Infrared spectra and thermal analysis of this compound were studied. DFT calculations were carried out and structural geometrical parameters were evaluated. In-silico molecular docking of tested ligand in Tankyrase I enzyme shows a number of hydrogen bond interactions, chlorine and aromatic ring interaction and polar contact, these predicted interactions can inhibit the active sites of amino acids of Tankyrase I enzyme, so this inhibition can control some biological activities especially anticancer effect.