Thermophysical and Transport Properties of the BaCl2-CsCl High Temperature Ionic Liquid Mixtures

High temperature ionic liquids (HTILs) densities and transport properties for mixtures BaCl2‑CsCl, x(BaCl2) = 0-1, have been studied as a function of composition and temperature. In terms of Arrhenius theory, the temperature correlation of all measured properties was made and discussed. Thermodynamic properties (isothermal compressibility, molecular volume, lattice energy, heat capacity, molar Gibbs energy, enthalpy and entropy) were derived for all the studied HTILs from experimental data. The viscosity isotherms show negative deviations from linearity, while conductivity isotherms have positive deviations which may be related to the formation of highly negative changed ion associated species. The evolution of the excess quantities: viscosity deviation (Δη), excess molar viscosity (ΔEη), excess molar conductivity (ΔEκ), show a very good parallelism. The linear behavior between conductivity and viscosity was determined using the fractional Walden rule and the average slope was found far from unity.

Phase diagram of solid hints new fundamental constant and sees atomic orbital

Cold and pressure transform gas into liquid and then into solid. Van der Waals understood the phase diagram of liquefiable gas with the molecular volume and intermolecular attraction, however, was silent on how solid behaved1. Unfortunately, solid-state phase diagram have remained uncomprehended mystery; only its straight boundary2,3 was explained by struggle of order vs. chaos. Here we show that the volume of orbital overlap has its own energy, with the universal density 8.941 eV/Å3 announced as new fundamental atomic constant that determines the transition temperature TC. Furthermore, we devised solid-state tomography, valid to 5 TPa, - imaging orbital through the baric dependencies of TC. Triangle-shaped pattern of the diagram is explained by the only possible way, just as only one plane passes through triangle: -inflation of the intersection volume during the transition determines hysteresis, but its disappearance does triple point; -approaching ions, whose orbitals overlap, curves the line from zero-field-cooling (ZFC) TC to triple point; -the straight line between zero-field-heating (ZFH) TC and triple point is a consequence of straightening tilting angle. Diamond melting point, calculated from volumes of the tetrahedral covalent bonds, excellently agrees with real; furthermore, the points up to 2 TPa agree with experiment4. Our findings open up way to interpret antiferromagnetism and steric effect in mono, binary, and ternary transition-metal oxides and sulfides5-11, and advance in unravelling unconventional superconductivity12,13, ascertaining the roles of s- and p-hybridizations. Thereby, the importance of the solid-state tomography for organic conductors12,13 being high-compressible and interior of stars can scarcely be exaggerated.

Ideal Gas Reference for Association and Dissociation Reactions: I. Basic Concepts

Starting with a distance-based definition of molecules consisting of non-interacting atoms, which is in line with IUPAC terminology, we construct an ideal gas reference for chemical association and dissociation reactions. The corresponding ideal equations for equilibria and kinetics reveal the mathematical structure, known for real systems, in comprehensible clarity. The ideal gas reference corresponds to the limit of an entirely flat potential energy surface of the system where chemical equilibria and kinetics are determined by "unspecific" particle number combinatorics according to the reaction stoichiometry. The ideal equilibrium and rate constants provide a reference for the definition of excess equilibrium and rate constants of real reactions that quantify all "system-specific" contributions resulting from the particular shape of the potential energy surface. The ideal gas reference therefore enables a distinction between unspecific and system-specific aspects in the equilibria and kinetics of chemical association/dissociation reactions. Whereas conventional equilibrium and rate constants suffer from incompatibility between reactions of different stoichiometry, excess equilibrium and rate constants can be consistently compared across different reaction orders. Furthermore, whereas the conventional treatment requires an arbitrary specification of reference concentrations, e.g. at standard conditions, the ideal gas framework introduces an intrinsic concentration scale that is equal to the inverse of a molecular volume.

Interaction of cisplatin anticancer drug with C20 bowl: DFT investigation

This study investigated the cisplatin (anticancer drug) interaction with C20 bowl and C20H10(Bowl) molecule including hydrogen-saturated with using mPW1PW91 functional. The stability of the various isomers of drug interaction with C20 bowl was investigated. The interaction energy values were estimated in these systems. Changes in the structural parameters and the frontier orbital energy and HOMO-LUMO gap values were evaluated. Charge transfer between fragments were shown with electrophilicity-based charge transfer (ECT). The Octanol–water partition coefficient (log P) and molecular volume (Vm) of these drug precursor molecules were studied. Also, Pt-C bond characterizations were illustrated using QTAIM analysis. The results showed that C20 bowl can be a promising nanocarrier for cisplatin anticancer drug.

Molecular electrostatic potential and pattern recognition models to design potentially active pentamidine derivatives against Trypanosoma brucei rhodesiense

Molecular electrostatic potential (MEP) and pattern recognition (PR) were used to draw potentially active pentamidine derivatives against Trypanosome brucei rhodesiense (T. b. rhodesiense). PR models: Principal Component Analysis, PCA model; Hierarchical Cluster Analysis, HCA model; K-Nearest Neighbor, KNN model; Soft Independent Modeling of Class Analogy, SIMCA model; and Stepwise Discriminant Analysis, SDA model, were built by reducing the dimensionality of a data matrix to twenty-eight pentamidine derivatives and allowed the compounds to be classified into two classes: more active and less active, according to their degrees of activity against T. b. rhodesiense. The study outlined that the properties HOMO (highest occupied molecular orbital) energy, VOL (molecular volume), and ASA_P (water accessible surface area of all polar (½qi½³0. 2) atoms) are the most relevant for the construction of the models. The key structural features required for biological activity investigated through MEP were used as guidelines in the design of thirteen new compounds, which were evaluated by PR models as more active or less active against T. b. rhodesiense. The application of PR models indicated nine promising compounds (29, 30, 31, 32, 33, 36, 37, 39, and 40) for synthesis and biological assays.

Synthesis, DFT Study and Bioactivity Evaluation of New Butanoic Acid Derivatives as Antiviral Agents

In the present work, at first, density functional theory (DFT) calculations were utilized for the molecular design of the four new butanoic acid derivatives at B3LYP/6-31+G(d) level of theory. After DFT calculations, synthesis, FT-IR, 1H NMR, and 13C NMR spectra of corresponding molecules were presented. The NBO analysis and electronic properties of the four new synthesized butanoic acid (1, 2, 3, 4) were carried out to compare their stability and reactivity. Finally, the values of octanol/water partition coefficient (miLogP), the molecular polar surface area (TPSA), the number of atoms of the molecule (natoms), the number of hydrogen bond acceptors (nON), the number of hydrogen bond donors (nOHNH), the number of violations of the Ro5 (nviolations), the number of rotatable bonds (nrotb), the molecular volume (Vm), the molecular weight (MW) and bioactivity scores were estimated and discussed.

Calculation of Mass Transfer and Cell-Specific Consumption Rates to Improve Cell Viability in Bioink Tissue Constructs

Biofabrication methods such as extrusion-based bioprinting allow the manufacture of cell-laden structures for cell therapy, but it is important to provide a sufficient number of embedded cells for the replacement of lost functional tissues. To address this issue, we investigated mass transfer rates across a bioink hydrogel for the essential nutrients glucose and glutamine, their metabolites lactate and ammonia, the electron acceptor oxygen, and the model protein bovine serum albumin. Diffusion coefficients were calculated for these substances at two temperatures. We could confirm that diffusion depends on the molecular volume of the substances if the bioink has a high content of polymers. The analysis of pancreatic 1.1B4 β-cells revealed that the nitrogen source glutamine is a limiting nutrient for homeostasis during cultivation. Taking the consumption rates of 1.1B4 β-cells into account during cultivation, we were able to calculate the cell numbers that can be adequately supplied by the cell culture medium and nutrients in the blood using a model tissue construct. For blood-like conditions, a maximum of ~106 cells·mL−1 was suitable for the cell-laden construct, as a function of the diffused substrate and cell consumption rate for a given geometry. We found that oxygen and glutamine were the limiting nutrients in our model.

Determination With QSAR of Biological Activity and Relations of Between Molecular Descriptions of 5,8-Quinolinequinones Derivatives

In this study, some electronic, hydrophobic and termochemical parameters of 28 different 5,8-quinolinequinones derivatives having diversity substituents have been calculated by using DFT (B3LYP) / 6-31G (d, p) method and basis set. Relationships between different molecular descriptives have been studied with used like molecular polarizability (α), dipole moment (μ), EHOMO, ELUMO, molecular volume (Vm), ionization potential (IP), electron affinity (EA), electronegativity (χ), molecular hardness (η), molecular softness (S), electrophilic index (Ꞷ), molar refractivity (MR), octanol–water partition coefficient (logP), thermochemical properties (entropy (Se), capacity of heat (C)); as to investigate activity relationships with molecular structure. In addition, The QSAR/QSPR between molecular properties and biological activity (Anti-proliferative and Anti-inflammatory activity) has investigated, where R, R2, F and P have taken into account in order to find a statistically correct model in QSAR studies. The dependence of the electronegative parameter on both electronic and thermochemical parameters was the most correlated parameter.

Molecular Dynamics Simulations Reveal Interactions of an IgG1 Antibody With Selected Fc Receptors

In a survey of novel interactions between an IgG1 antibody and different Fcγ receptors (FcγR), molecular dynamics simulations were performed of interactions of monoclonal antibody involved complexes with FcγRs. Free energy simulations were also performed of isolated wild-type and substituted Fc regions bound to FcγRs with the aim of assessing their relative binding affinities. Two different free energy calculation methods, Molecular Mechanical/Generalized Born Molecular Volume (MM/GBMV) and Bennett Acceptance Ratio (BAR), were used to evaluate the known effector substitution G236A that is known to selectively increase antibody dependent cellular phagocytosis. The obtained results for the MM/GBMV binding affinity between different FcγRs are in good agreement with previous experiments, and those obtained using the BAR method for the complete antibody and the Fc-FcγR simulations show increased affinity across all FcγRs when binding to the substituted antibody. The FcγRIIa, a key determinant of antibody agonistic efficacy, shows a 10-fold increase in binding affinity, which is also consistent with the published experimental results. Novel interactions between the Fab region of the antibody and the FcγRs were discovered with this in silico approach, and provide insights into the antibody-FcγR binding mechanism and show promise for future improvements of therapeutic antibodies for preclinical studies of biological drugs.