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For the first time, two distinct trends are clearly evidenced for the enthalpies and entropies of vaporization along the [Cnmim][Ntf2] ILs series. The trend shifts observed for Δ(l)(g)H(m)(o) and Δ(l)(g)S(m)(o), which occur at [C6mim][Ntf2], are related to structural modifications. The thermodynamic results reported in the present article constitute the first quantitative experimental evidence of the structural percolation phenomenon and make a significant contribution to better understanding of the relationship among cohesive energies, volatilities, and liquid structures of ionic liquids. A new Knudsen effusion apparatus, combined with a quartz crystal microbalance, was used for the high-accuracy volatility study of the 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide series ([Cnmim][Ntf2], where n = 2, 3, 4, 5, 6, 7, 8, 10, 12). Vapor pressures in the (450–500) K temperature range were measured, and the molar standard enthalpies, entropies, and Gibbs energies of vaporization were derived. The thermodynamic parameters of vaporization were reported, along with molecular dynamic simulations of the liquid phase structure, allowing the establishment of a link between the thermodynamic properties and the percolation phenomenon in ILs.

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The discovery of potent and selective monoamine oxidase-B inhibitors for the management of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases is still a challenging endeavor. Herein, we report the discovery of two new classes of potent and selective MAO-B inhibitors based on chromane-2,4-dione and chromone-3-carboxamide scaffolds.

The interactions between water and n-perfluoroalkanes or substituted R-(ω-)fluoroalkanes used in blood substitute formulations were investigated experimentally and using ab initio calculations. The solubility of water in C 6 -C 9 perfluoroalkanes and five C 8 analogues of substituted fluoroalkanes was measured in the temperature range between 288 and 318 K at atmospheric pressure, using a Karl Fischer coulometer. From these data, the thermodynamic functions and partial molar solvation quantities such as Gibbs energy, enthalpy, and entropy were determined and compared with the interaction energies in 1:1 water-fluoroalkane complexes in vacuum, obtained using B3LYP/6-311++G(d,p). The experimental solubility data indicates a significant specific interaction between the water and the R-(ω-)substitute atom (H, I, Br, or Cl) in the fluoroalkanes.

The thermodynamic and structural study of a series of polyphenylbenzenes, from benzene, n(Ph) = 0, to hexaphenylbenzene, n(Ph) = 6, is presented. The available literature data for this group of compounds was extended by the determination of the relevant thermodynamic properties for 1,2,4-triphenylbenzene, 1,2,4,5-tetraphenylbenzene, and hexaphenylbenzene, as well as structural determination by X-ray crystallography for some of the studied compounds. Gas phase energetics in this class of compounds was analyzed from the derived standard molar enthalpies of formation in the gaseous phase. The torsional profiles relative to the phenyl-phenyl hindered rotations in some selected polyphenylbenzenes, as well as the gas phase structures and energetics, were derived from quantum chemical calculations. In the ideal gas phase, a significant enthalpic destabilization was observed in hexaphenylbenzene relative to the other polyphenylbenzenes, due to steric crowding between the six phenyl substituents. A relatively low enthalpy of sublimation was observed for hexaphenylbenzene, in agreement with the decreased surface area able to establish intermolecular interactions. The apparently anomalous low entropy of sublimation observed for hexaphenylbenzene is explained by its high molecular symmetry and the six highly hindered phenyl internal rotations. For the series of polyphenylbenzenes considered, it was shown that the differentiation in the entropy of sublimation can be chiefly ascribed to the torsional freedom of the phenyl substituents in the gas phase and the entropy terms related with molecular symmetry.