Electrostatic Potential Surface Research Articles

Novel quinazolinone derivatives as anticancer agents: Design, synthesis, biological evaluation and computational studies

A novel series of quinazoline-pyrimidine derivatives (3a-3i) linked to different aryl substitutions were designed and synthesized as promising anti-cancer candidates. The Chemical structures of the new compounds were confirmed by IR, 1HNMR, 13CNMR, and Mass spectroscopy. Antiproliferative activities of all synthesized compounds were evaluated against MCF-7 and SW480 cell lines by the MTT method. The biological results exhibited IC50 values in the range of 1.1 to 59.0 μM. Compounds 3d and 3f were found to be the most active compounds against the SW480 cell line, with IC50 = 1.1 and 8 μM respectively. Furthermore, in silico analyses of the Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) profiles of the synthesized compounds exhibited that our molecules have acceptable predictive ADMET features. The results of the docking studies were in line with biological outputs, Density functional theory (DFT) studied 3a and 3d's reactivity descriptors at the B3LYP/6-31G** level of theory. HOMO, LUMO, and electrostatic surface potential energy were also examined. According to DFT calculations, compound 3d exhibits higher reactivity than compound 3a, which is consistent with the experimental observations. Molecular dynamic simulation of the potent synthetic compound (3d) and native ligand (Erlotinib) was performed to validate the docking study and also, RMSD, RMSF, total hydrogen bond, and clusters were analyzed.

Surface hydroxylation mechanism of Zr[formula omitted]X(OH)[formula omitted] (X = C, N, or B) MXenes: A promising catalyst for CO[formula omitted] conversion into formic acid

Electrocatalytic transformation of CO2 to formic acid is typically realized via bi-hydrogenation process, which is remarkably challenging because of high thermodynamic stability and chemical inertness of the intermediate. Here, we explored the surface hydroxylation mechanism for CO2 conversion into formic acid over OH-terminated MXenes that can effectively circumvent the thermodynamic sink of the conventional bi-hydrogenation process by capturing additional hydrogen from the surface. The observed unique CO2RR activity can be attributed to the reactive H atom on the OH-terminated MXenes. The facile capture of (H) from OH-terminated MXenes confirm the viability of surface-hydroxylation mechanism. In addition, the ultra low work functions (1.72–2.27 eV) of such materials demonstrate the significance of functional groups in deciding the surface electrostatic potential of MXenes during the etching process. Overall, the present study bypass the thermodynamic constraints hampering the formation of formic acid by eliminating the intermediate step in the CO2 hydrogenation reaction and is likely to have considerable implications in the fields of catalytic chemistry and CO2 conversion.

SPECTROSCOPIC, NLO, NBO, BIOCHEMICAL INVESTIGATION OF 3-(HYDROXYMETHYL)-3-METHYL-2,6-DIPHENYLPIPERIDIN-4-ONE

The piperidine put deep attention to research due to their pharmacological activity and hence drug designing. The derivatives of piperidine have important activities against cancers and tumor disease. Cancer is the most difficult disease in the world (WHO) which is basically considered to be the uncontrolled growth of abnormal cells. In present communication structural and vibrational features of piperidine derivatives 3-(hydroxymethyl)-3-methyl-2,6-diphenylpiperidin-4-one has been computed based on theoretical quantum chemical approach. The primary aspects of piperidine derivatives 3-(hydroxymethyl)-3-methyl-2,6-diphenylpiperidin-4-one structure has been calculated by using optimized geometry, spectroscopic behavior, chemical reactivity and molecular docking analysis. The info about coupled of modes were founded in vibrational features of the molecule. The stability of the chemical reactivity of 3-(hydroxymethyl)-3-methyl-2,6-diphenylpiperidin-4-one was predicted by using HOMO-LUMO energy gap. The molecular electrostatic surface potential (MESP) plot utilizes overall picture of accretion of charges on separate atoms in molecule which very useful predict the nucleophilic and electrophilic charge center. The pharmacological importance of piperidine derivatives 3-(hydroxymethyl)-3-methyl-2,6-diphenylpiperidin-4-one is established by calculated biological activity. The inhibition properties and chemical reactivity of piperidine derivatives 3-(hydroxymethyl)- 3-methyl-2,6-diphenylpiperidin-4-one are well-known by chemical reactivity descriptors by using HOMO-LUMO energies. The inhibition potentials of piperidine derivatives 3-(hydroxymethyl)- 3-methyl-2,6-diphenylpiperidin-4-one are established by calculated lipophilicity, aqueous solubility, and binding affinity. The docking of molecule has been also performed with suitable target.

Spectroscopic, quantum chemical investigation and molecular docking studies on N-(2-benzoylamino) phenyl benzamide: A novel SARS-CoV-2 drug.

The present work describes the structural and spectral properties of N-(2-benzoylamino) phenyl benzamide (NBPB). The geometrical parameters of NBPB molecule such as bond lengths, bond angles and dihedral angles are calculated and compared with experimental values. The assigned vibrational wave numbers are in good agreement with the experimental FTIR and FT Raman spectra. The vibrational frequency of C=O stretching was downshifted to a lower wave number (red shift) due to mesomeric effect. The UV-Vis spectrum of the title compound was simulated and validated experimentally. The energy gap and charge transfer interaction of the title molecule were studied using frontier molecular orbital analysis. The electrophilic and nucleophilic reactivity sites of NBPB were investigated through the analysis of the molecular electrostatic potential surface and the Fukui function. An assessment of the intramolecular stabilization interactions of the molecule was performed using natural bond orbital analysis. The drug-likeness parameter was calculated. To investigate the inhibitory potential of the molecule, molecular docking analysis was conducted against SARS-CoV-2 proteins, revealing its capability to serve as a novel inhibitor against SARS-CoV-2. The high binding affinity of NBPB molecule was due to the presence of hydrogen bonds along with different hydrophobic interactions between the drug and the SARS-CoV-2 protein receptor. Hence, the title molecule is identified to be a potential candidate for SARS-CoV-2.

Indapamide analogue a promising drug: Synthesis, a novel crystal structure, HSA/DFT/XRD, greener pastures biological study

A new indoline derivative, N-allyl-4-chloro-3-(N,N-diallylsulfamoyl)-N-(2-methylindolin-1-yl)benzamide (ASIB), indapamide analogue, has been synthesized via the N-allylation reaction and characterized by ESI-MS, IR, 1H & 13C NMR. The geometric parameters of the title compound, whose crystallographic structure has been defined by X-ray diffraction, have been calculated by Density Functional Theory (DFT), B3LYP, 6–311++G(d,p) basis set. For these operations, the data obtained by X-ray diffraction was used as initial values, and the calculated geometric parameters and experimental results were compared. In order to understand intermolecular interactions, Molecular Electrostatic Potential (MEP) and Hirshfeld Surface Analysis (HSA) studies were figured out for the molecule. Frontier Molecular Orbitals (FMO's) were created, and Energy Gap between Lowest Unoccupied Molecular Orbital (LUMO) and Highest Occupied Molecular Orbital (HOMO) was calcculated. Adapting Greener Pastures Biological Study (GPBS) aims to conduct a fair comparative study using accessible computer-aided software. ASIB, Indapamide, Asunaprevir, Danoprevir, and Vaniprevir were docked together using the same conditions and parameters to ensure a fair comparison. The binding scores against 6LU7 were −6.6, −7.1, −8.4, 7.6, and −7.9 kcal/mol−1 for ASIB, Indapamide, Asunaprevir, Danoprevir, and Vaniprevir, respectively. A relation between the molecule's binding score was due to the hydrophobic and hydrogen interactions between the ligand and the receptor's active amino acid residues. Worth pointing out here that the free energy and environmentally friendly in Silico molecular docking method aims mainly to rank ASIB, and Indapamide with respect to the approved drugs used in this study. Results support further investigation of ASIB as non-toxic a Diuretic, anti-COVID-19 and powerful antiviral drug as an indapamide derivative. Way2drug-PASS, Pro Tox-II and SwissADME are online software tools used in this study. Absorption, distribution, metabolism, excretion and toxicity (ADMET) properties of ASIB and its starting material (Indapamide) were compared.

Spectroscopic investigations, quantum chemical, molecular docking and drug likeness studies of t-butyl-3,4,5-trimethyl-2-pyrrole carboxylate

The geometrical structure of t‑butyl‑3,4,5-trimethyl-2-pyrrole carboxylate (TBTPC) was computed by DFT calculations using the B3LYP method and the 6–311++G(d,p) basis set using the Gaussian 09 software. Vibrational wavenumbers were assigned using the VEDA 4.0 program. Natural bond orbital (NBO) analysis predicts the hyper-conjugative interaction and stabilization interaction of the TBTPC compound. HOMO, LUMO, and other molecular properties were calculated. The density of states (DOS) spectrum was also predicted. The ultraviolet-visible spectrum has been experimentally and theoretically validated and simulated. The electrophilic and nucleophilic reactive sites of the TBTPC molecule were determined using the Fukui function calculation and the molecular electrostatic potential (MEP) surface. Molecular docking analysis of the TBTPC ligand helps to investigate its inhibitory nature against Lysine-specific demethylase 1A (LSD1), α-amylase, BCL-1, and monoamine oxidase (MAO). From the molecular docking results, TBTPC has promising inhibition activity against gastric cancer.

Synthesis, Molecular Docking, and Biological Evaluation of Novel Anthranilic Acid Hybrid and Its Diamides as Antispasmodics.

The present article focuses on the synthesis and biological evaluation of a novel anthranilic acid hybrid and its diamides as antispasmodics. Methods: Due to the predicted in silico methods spasmolytic activity, we synthesized a hybrid molecule of anthranilic acid and 2-(3-chlorophenyl)ethylamine. The obtained hybrid was then applied in acylation with different acyl chlorides. Using in silico analysis, pharmacodynamic profiles of the compounds were predicted. A thorough biological evaluation of the compounds was conducted assessing their in vitro antimicrobial, cytotoxic, anti-inflammatory activity, and ex vivo spasmolytic activity. Density functional theory (DFT) calculation, including geometry optimization, molecular electrostatic potential (MEP) surface, and HOMO-LUMO analysis for the synthesized compounds was conducted using the B3LYP/6-311G(d,p) method to explore the electronic behavior, reactive regions, and stability and chemical reactivity of the compounds. Furthermore, molecular docking simulation along with viscosity measurement indicated that the newly synthesized compounds interact with DNA via groove binding mode. The obtained results from all the experiments demonstrate that the hybrid molecule and its diamides inherit spasmolytic, antimicrobial, and anti-inflammatory capabilities, making them excellent candidates for future medications.

Alternative splicing of a single exon causes a major impact on the affinity of Caenorhabditis elegans tropomyosin isoforms for actin filaments.

Tropomyosin is generally known as an actin-binding protein that regulates actomyosin interaction and actin filament stability. In metazoans, multiple tropomyosin isoforms are expressed, and some of them are involved in generating subpopulations of actin cytoskeleton in an isoform-specific manner. However, functions of many tropomyosin isoforms remain unknown. Here, we report identification of a novel alternative exon in the Caenorhabditis elegans tropomyosin gene and characterization of the effects of alternative splicing on the properties of tropomyosin isoforms. Previous studies have reported six tropomyosin isoforms encoded by the C. elegans lev-11 tropomyosin gene. We identified a seventh isoform, LEV-11U, that contained a novel alternative exon, exon 7c (E7c). LEV-11U is a low-molecular-weight tropomyosin isoform that differs from LEV-11T only at the exon 7-encoded region. In silico analyses indicated that the E7c-encoded peptide sequence was unfavorable for coiled-coil formation and distinct from other tropomyosin isoforms in the pattern of electrostatic surface potentials. In vitro, LEV-11U bound poorly to actin filaments, whereas LEV-11T bound to actin filaments in a saturable manner. When these isoforms were transgenically expressed in the C. elegans striated muscle, LEV-11U was present in the diffuse cytoplasm with tendency to form aggregates, whereas LEV-11T co-localized with sarcomeric actin filaments. Worms with a mutation in E7c showed reduced motility and brood size, suggesting that this exon is important for the optimal health. These results indicate that alternative splicing of a single exon can produce biochemically diverged tropomyosin isoforms and suggest that a tropomyosin isoform with poor actin affinity has a novel biological function.

Cancer-associated somatic mutations in human phosphofructokinase-1 reveal a critical electrostatic interaction for allosteric regulation of enzyme activity.

Metabolic reprogramming, including increased glucose uptake and lactic acid excretion, is a hallmark of cancer. The glycolytic "gatekeeper" enzyme phosphofructokinase-1 (PFK1), which catalyzes the step committing glucose to breakdown, is dysregulated in cancers. While altered PFK1 activity and expression in tumors have been demonstrated, little is known about the effects of cancer-associated somatic mutations. Somatic mutations in PFK1 inform our understanding of allosteric regulation by identifying key amino acid residues involved in the regulation of enzyme activity. Here, we characterized mutations disrupting an evolutionarily conserved salt bridge between aspartic acid and arginine in human platelet (PFKP) and liver (PFKL) isoforms. Using purified recombinant proteins, we showed that disruption of the Asp-Arg pair in two PFK1 isoforms decreased enzyme activity and altered allosteric regulation. We determined the crystal structure of PFK1 to 3.6Å resolution and used molecular dynamic simulations to understand molecular mechanisms of altered allosteric regulation. We showed that PFKP-D564N had a decreased total system energy and changes in the electrostatic surface potential of the effector site. Cells expressing PFKP-D564N demonstrated a decreased rate of glycolysis, while their ability to induce glycolytic flux under conditions of low cellular energy was enhanced compared to cells expressing wild-type PFKP. Taken together, these results suggest that mutations in Arg-Asp pair at the interface of the catalytic-regulatory domains stabilizes the t-state and presents novel mechanistic insight for therapeutic development in cancer.

Theoretical and experimental cocrystal screening of temozolomide with a series of phenolic acids, promising cocrystal coformers

The virtual cocrystal screening approach based on molecular electrostatic potential surface (MEPS) maps is a fast and feasible computational method to estimate the probability of cocrystal formation by calculating the difference in the interaction site pairing energies of monomers and that of their assemblies prior to experimental screening. In this paper, we report 12 cocrystal forms of temozolomide with mono-, di-, and trihydroxy benzoic acids, namely, 3‑hydroxy-, 2,4-dihydroxy-, 2,5-dihydroxy-, 2,6-dihydroxy-, 3,4-dihydroxy-, and 3,4,5-trihydroxy-benzoic acids, as well as benzoic acid, as pharmaceutical coformers for the first time. 10 single crystals out of the 12 cocrystal forms were obtained and unequivocally determined by single-crystal X-ray diffraction, which clarified spatial arrangements, molecular conformations, and supramolecular synthons. MEPS further gains some insights into the sites of hydrogen bonding interactions for exploring combination patterns in these assemblies. Modulated stability of TMZ was successfully achieved by cocrystallization with these acids.

Ag‐based bimetallic clusters as catalysts for p‐nitrophenol reduction by glycerol: A DFT investigation

AbstractReducing p‐nitrophenol (PNP) to p‐aminophenol is an industrially relevant synthesis. Nevertheless, only a few heterogeneous catalysts have been evaluated for the reduction of PNP by glycerol. Appropriate quantum computational studies can screen potential catalysts for this crucial green reaction. The present research investigates the catalytic activities of Pd@Ag and Ni@Ag core‐shell nanogeometries toward PNP reduction by glycerol through density functional theory (DFT) calculations. The central atom of a geometry‐optimized 13‐atom Ag cluster was replaced by Pd and Ni atoms to create the core‐shell morphologies. The interaction energies of PNP and glycerol with each of the (metal/bimetallic) clusters were evaluated by DFT calculations to find the best PNP and glycerol molecule orientation with the respective bimetallic cluster. Electrostatic potential surface and natural bond orbital analyses were performed to study the charge distribution and transfer between atomic orbitals. The frequencies of vibrational modes in isolated PNP/glycerol structures were compared to those when these molecules were in the presence of the different metal clusters to infer the effect of the interactions. All performed analyses indicated improved catalytic activity toward PNP reduction by glycerol upon Ni‐doping of the Ag13 cluster.

Efficient removal of tetracycline by a novel bimetallic nickel/copper-loaded biochar: The crucial roles of π-π interaction and complexation

The development of a novel type of high-efficient biochar (BC) is important for the removal of tetracycline (TC). In this study, a bimetallic nickel/copper-loaded BC (Ni/Cu-BC) was synthesized, which had not been used for TC removal and lacked research on its safety and stability. The adsorption process was more likely to be monolayer chemical adsorption from the experiment. The density functional theory (DFT) calculation revealed that the interaction energy (Eads), energy gap (Eg) and dipole moment (P(D)) confirmed that the bimetallic loading improved the adsorption strength of the BC to TC. Moreover, the distribution of Ni/Cu-BC surface charge was considerably different from BC after bimetallic loading, and local polarization occurred according to the analysis of molecular surface electrostatic potential (ESP). It was demonstrated that the π-π interaction and complexation played a crucial role in the removal of TC. Finally, the functional groups of Ni/Cu-BC in removal were in the following order: CO > CC > NH2 > MO > CO. This study proves that Ni/Cu-BC is a novel, high-efficient, safe and reusable adsorbent. Overall, this study provides a new perspective on the design of BC and develops its environmental applications.

Multiphase Porous Electrode Theory for the Next Generation of SOFC/SOEC Electrodes

The mixed-ionic electronic conduction (MIEC) of gadolinium doped ceria (CGO) under reduced oxygen conditions makes it an excellent fuel electrode material for SOFC/SOEC applications. As part of a composite electrode (Ni/CGO), the nickel phase offers a fast electronic conduction pathway to the current collector and may act as an electrocatalyst at the three-phase boundary. Although the Ni/CGO cermet provides superior electrochemical performance compared with older technologies such as Ni/YSZ, the models used to study MIEC materials do not capture the unique transport and kinetic physics which makes them an excellent choice for the next generation of fuel electrodes. Within the framework of multiphase porous electrode theory, this work provides a novel set of differential-algebraic equations which captures the effects of the activation overpotential on electronic defect concentration, electrostatic surface potential and ionic transport to accurately predict the current-voltage behaviour of the Ni/CGO electrode. Moreover, through concerted electron and proton tunnelling events, we unify the theory of the electrostatic surface potential with proton-coupled electron transfer kinetics.

Observation of Termination-Dependent Topological Connectivity in a Magnetic Weyl Kagome Lattice.

Engineering surfaces and interfaces of materials promises great potential in the field of heterostructures and quantum matter designers, with the opportunity to drive new many-body phases that are absent in the bulk compounds. Here, we focus on the magnetic Weyl kagome system Co3Sn2S2 and show how for the terminations of different samples the Weyl points connect differently, still preserving the bulk-boundary correspondence. Scanning tunneling microscopy has suggested such a scenario indirectly, and here, we probe the Fermiology of Co3Sn2S2 directly, by linking it to its real space surface distribution. By combining micro-ARPES and first-principles calculations, we measure the energy-momentum spectra and the Fermi surfaces of Co3Sn2S2 for different surface terminations and show the existence of topological features depending on the top-layer electronic environment. Our work helps to define a route for controlling bulk-derived topological properties by means of surface electrostatic potentials, offering a methodology for using Weyl kagome metals in responsive magnetic spintronics.

Effect of Total Dose Irradiation on Parasitic BJT in 130 nm PDSOI MOSFETs.

In this work, the effects of total dose irradiation on the parasitic bipolar junction transistor (BTJ) in 130 nm PDSOI MOSFETs were investigated. The experimental results demonstrate that irradiation-induced oxide-trap charges can modify the E-B junction barrier, and thereby make the common-emitter gain β0 of the parasitic BJT in NMOS device increase, while decreasing it in a PMOS device. Additionally, irradiation-generated oxide-trap charges in shallow trench isolation (STI) elevate the surface electrostatic potential of the gate above the STI sidewall, thus providing an additional channel from the emitter to the collector. Moreover, these charges may generate parasitic reverse conductive paths at the STI/Si interface under high dose irradiation, thereby enhancing the leakage current in the front gate channel and diminishing the significance of the parasitic BJT. Under irradiation, the electric field intensity difference between two biases leads to higher β0 of the parasitic BJT in PG-biased devices than in ON-biased ones. Furthermore, the lifting effect of irradiation on β0 increases in wide or short channel irradiated devices, which can be explained using simulations and an emitter current crowding effect model.

Panchromatic Light-Capturing Bis-styryl BODIPY-Perylenediimide Donor-Acceptor Constructs: Occurrence of Sequential Energy Transfer Followed by Electron Transfer.

Two wide-band-capturing donor-acceptor conjugates featuring bis-styrylBODIPY and perylenediimide (PDI) have been newly synthesized, and the occurrence of ultrafast excitation transfer from the 1 PDI* to BODIPY, and a subsequent electron transfer from the 1 BODIPY* to PDI have been demonstrated. Optical absorption studies revealed panchromatic light capture but offered no evidence of ground-state interactions between the donor and acceptor entities. Steady-state fluorescence and excitation spectral recordings provided evidence of singlet-singlet energy transfer in these dyads, and quenched fluorescence of bis-styrylBODIPY emission in the dyads suggested additional photo-events. The facile oxidation of bis-styrylBODIPY and facile reduction of PDI, establishing their relative roles of electron donor and acceptor, were borne out by electrochemical studies. The electrostatic potential surfaces of the S1 and S2 states, derived from time-dependent DFT calculations, supported excited charge transfer in these dyads. Spectro-electrochemical studies on one-electron-oxidized and one-electron-reduced dyads and the monomeric precursor compounds were also performed in a thin-layer optical cell under corresponding applied potentials. From this study, both bis-styrylBODIPY⋅+ and PDI⋅- could be spectrally characterizes and were subsequently used in characterizing the electron-transfer products. Finally, pump-probe spectral studies were performed in dichlorobenzene under selective PDI and bis-styrylBODIPY excitation to secure energy and electron-transfer evidence. The measured rate constants for energy transfer, kENT , were in the range of 1011 s-1 , while the electron transfer rate constants, kET , were in the range of 1010 s-1 , thus highlighting their potential use in solar energy harvesting and optoelectronic applications.

Adsorption of Tunable aryl alkyl ionic liquids (TILs) on the graphene and Defective graphene nanosheets: A DFT Study

Optical and electronic characteristics of the graphene nanosheets (GNS) could be altered by some structural defects such as double-vacancy and Stone-Wales ones. The physisorption manner of [MPI][BF4], [MPT1][BF4], [MPT2][BF4], and [MPTT][BF4] ionic liquids on intact and defective GNS surfaces were investigated using M06-2X/cc-pVDZ computational method. Capability for adsorption on the DV and SW graphene surfaces by TILs is increased by about 1.0–4.3 and 0.4–2.0 kcal/mol respectively. The electrostatic potential of the GNS-DV surface is more negative than the GNS-SW one which enables it to interact with cation parts of the adsorbed TILs so extensively. The highest adsorption energy belongs to the [MPI][BF4]/GNS-DV system. Adsorption of the TILs on the GNS surfaces leads to a decrease in the energy of the LUMO molecular orbital as well as their energy gap of them. Results revealed that the electrical conductivity, as well as absorption spectra of the GNS surfaces, are affected by TILs adsorption and defect nature.

Experimental and computational studies of two binuclear Co(II) and Ni(II) bis(salamo)‐like complexes

Acetate‐bridged binuclear Co(II) and Ni(II) complexes, [Co2(L)(μ‐OAc)(EtOH)] (1) and [Ni2(L)(μ‐OAc)(EtOH)] (2) were synthesized via the reaction of a new bis(salamo)‐like ligand with two different metal(II) acetates. X‐ray single crystal diffraction analyses showed that two metal(II) ions (Co or Ni) occupy two sets of N2O2 cavities, respectively. The acetate group bridges the two metals, and the ethanol oxygen atom participates in the coordination. Furthermore, UV–vis titration experiments clearly indicated that the complexation between H3L and M(II) ions leads to the 1:2 complexes [(L)M2]+ through a highly synergistic process. Bond valence sum (BVS) calculations exhibited that the Co(II) and Ni(II) ions are divalent. Secondly, the ligand H3L highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO‐LUMO) gap analysis and surface electrostatic potential were theoretically analyzed by theoretical calculation (density functional theory), and the reactivity of M(II) ions and the ligand in the complex formation process was demonstrated. Finally, the microscopic properties of the complexes were deeply understood through the calculation of the weak intramolecular interactions and the unstressed regions outside the complexes.

On the Importance of Halogen and Chalcogen Bonds in the Solid State of Nucleic Acids: A Combined Crystallographic and Theoretical Perspective.

In this work, intra- and intermolecular halogen and chalcogen bonds (HlgBs and ChBs, respectively) present in the solid state of nucleic acids (NAs) have been studied at the RI-MP2/def2-TZVP level of theory. To achieve this, a Protein Data Bank (PDB) survey was carried out, revealing a series of structures in which Br/I or S/Se/Te atoms belonging to nucleobases or pentose rings were involved in noncovalent interactions (NCIs) with electron-rich species. The energetics and directionality of these NCIs were rationalized through a computational study, which included the use of Molecular Electrostatic Potential (MEP) surfaces, the Quantum Theory of Atoms in Molecules (QTAIM), and Non Covalent Interaction plot (NCIplot) and Natural Bonding Orbital (NBO) techniques.

Equilibrium solubility, solvent effect, equation correlation, and thermodynamic properties of cyclododecanone in twelve organic solvents

The solubility of cyclododecanone (CDON) was determined in twelve solvents containing acetonitrile, acetone, toluene, ethyl acetate, cyclohexane, 1,2-dichloroethane, methanol, ethanol, n-propanol, i-propanol, n-butanol and i-butanol. The temperature range for the remaining solvents used in the experiment was 278.15–313.15 K, except for cyclohexane (283.15–313.15 K). The CDON solubility in solvents measured increased with growing temperature. The CDON solubility varies considerably in different solvents. Among the single solvents selected, CDON was most soluble in 1,2-dichloroethane and least in acetonitrile. The solubility in 1,2-dichloroethane is about 2–3 times higher than in acetonitrile. The carbonyl oxygen of CDON readily combines with alcoholic solvents to form hydrogen bonds. Hansen solubility parameters (HSP) and the physiochemical properties of the solvents explain the solvent effect in diverse solvents. To understand CDON dissolution, the electrostatic potential energy surfaces of CDON and the solute–solvent interactions were analyzed at the molecular level on the basis of density functional theory (DFT). Analysis of solvation effects revealed that variations in the CDON dissolution are influenced by a combination of factors rather than a single one. In addition, the Van't Hoff equation, modified Apelblat equation, Yaws equation, λh equation, Wilson model and Jouyban model were utilized to correlate the experimentally obtained value. The computational data show that the ARD (0.88%) and RMSD (0.24%) of Wilson model are the smallest among the selected equations with the best correlation. The apparent thermodynamic properties of CDON dissolution were further accounted for Van't Hoff equation, and the CDON dissolution was observed to be endothermic and entropy-driven.