We evaluate the first excited-state (S-1) intermolecular potential energy surface for the fluorobenzene-Ar van der Waals complex using the coupled cluster method and the augmented correlation-consistent polarized valence double-zeta basis set extended with a set of 3s3p2d1f1g midbond functions. To calculate the S-1 interaction energies, we use ground-state interaction energies evaluated with the same basis set and the coupled cluster singles and doubles (CCSD) including connected triple excitations [CCSD(T)] model and interaction and excitation energies evaluated at the CCSD level. The surface minima are characterized by the Ar atom located above and below the fluorobenzene ring at a distance of 3.5060 A with respect to the fluorobenzene center of mass and at an angle of 5.89 degrees with respect to the axis perpendicular to the fluorobenzene plane. The corresponding interaction energy is -425.226 cm(-1). The surface is used in the evaluation of the intermolecular level structure of the complex, and the results are compared to the experimental data available and to those found in previous theoretical papers on ground-state potentials for similar complexes.

The latest results of voltammetric research on the ionic transfer process of ionisable drugs across bare and lipid-modified liquid-liquid interfaces are reviewed. In recent years, two voltammetric methods have been extensively applied to this purpose, i.e. the classical four electrode voltammetry at the interface between two immiscible electrolyte solutions, and the "three-phase electrode." Thus, a brief background of the methodologies and some successful examples of their application are highlighted in this work. Particular attention is given to the ionic transfer kinetics and to the electro-chemical characterization of the drug-membrane interactions between the ionized drugs and lipid-modified interfaces. Future trends in this area are also mentioned in connection with high-throughput assessment of ADMET properties of drugs.

The kinetics of the transfer of a series of hydrophilic monovalent anions across the water/nitrobenzene (W/NB) interface has been Studied by means of thin organic film-modified electrodes in combination with electrochemical impedance spectroscopy and square-wave voltammetry. The Studied ions are Cl-, Br-, I-, ClO4-, NO3-, SCN-, and CH3COO-. The electrode assembly comprises a graphite electrode (GE) covered with a thin NB film containing a neutral strongly hydrophobic redox probe (decamethylferrocene or lutetium bis(tetra-tert-butylphthalocyaninato)) and an organic supporting electrolyte. The modified electrode is immersed in an aqueous solution containing a supporting electrolyte and transferring ions, and used in a conventional three-electrode configuration. Upon oxidation of the redox probe, the overall electrochemical process proceeds as an electron-ion charge-transfer reaction coupling the electron transfer at the GE/NB interface and compensates ion transfer across the W/NB interface. The rate of the ion transfer across the W/NB interface is the limiting step in the kinetics of the overall coupled electron-ion transfer reaction. Moreover. the transferring ion that is initially present in the aqueous phase only at a concentration lower than the redox probe, controls the mass transfer regime in the overall reaction. A rate equation describing the kinetics of the ion transfer that is valid for the conditions at thin organic film-modified electrodes is derived. Kinetic data measured with two electrochemical techniques are in very good agreement.

The rovibrational spectrum of the He-HF van der Waals complex is calculated from an accurate intermolecular potential energy surface. This is obtained by fitting a considerable number of interaction energies evaluated at the Coupled Cluster Singles and Doubles level including connected triple corrections and with an augmented correlation consistent polarized valence quintuple zeta basis set extended with a set of 3s3p2d1f1g mid-bond functions. The basis set was selected after a systematic study carried out at four intermolecular geometries. The potential is characterized by two linear minima, i.e., He-HF and He-FH, with distances rom the He atom to the HF centre of mass of 3.1662 angstrom and 2.9989 angstrom and binding energies of -43.844 and -26.169 cm(-1), respectively. These results are compared to data available in the literature. An analytic fit to this potential energy surface is presented and used to compute several low-lying rovibrational energy states using coupled channel methods. These results are compared with fixed-frame diffusion Monte-Carlo calculations using a method developed specifically for linear molecules.

We evaluate the rovibrational spectrum of the He-HCl van der Waals complex from an accurate ground state intermolecular potential, obtained from CCSD(T) interaction energies. After a systematic basis set study, we select the aug-cc-pV5Z basis set extended with midbond functions. The potential is characterized by two linear minima, i.e., He-CIH and He-HCl,. with distances from the He atom to the HCl centre of mass of 3.349 and 3.832 angstrom, respectively; and energies of -32.74 and -31.16 cm(-1)., respectively. The rovibrational spectra for the different isotopic species are calculated. The results are compared to those previously available.

The carcinogenic potency (TD50) of a set of 62 nitrosocompounds is predicted, applying the QSAR theory. Around thousands of molecular descriptors obtained from the DRAGON 2.1 software are used in order to model the toxicological property bioassay in female rat and considering the water as route of administration. For building the regression model three different methods of variable selection are used, namely the Forward Stepwise Regression, the Genetics Algorithms, and an alternative of the Elimination Method: the Replacement Method. The Replacement Method is used, for the first time, to predict the carcinogenic potency, achieving the best results. The best obtained model had seven variables and it was able to explain 84.3% of the experimental variance after removing 6 chemicals, which are considered as outliers.

A multidisciplinary project was developed, combining the synthesis of a series of beta-nitrostyrene derivatives and the determination of their physicochemical parameters (redox potentials, partition coefficients), to the evaluation of the corresponding antibacterial activity. A complete conformational analysis was also performed, in order to get relevant structural information. Subsequently, a structure-property-activity (SPAR) approach was applied, through linear regression analysis, aiming at obtaining a putative correlation between the physicochemical parameters of the compounds investigated and their antibacterial activity (both against standard strains and clinical isolates). The beta-nitrostyrene compounds displayed a lower activity towards all the tested bacteria relative to the beta-methyl-beta-nitrostyrene analogues. This was observed particularly for the 3-hydroxy-4-methoxy-beta-methyl-beta-nitrostyrene (IVb) against the Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium). The SPAR results revealed the existence of a clear correlation between the redox potentials and the antibacterial activity of the series of beta-nitrostyrene derivatives under study.

A catanionic surfactant consists of paired oppositely charged surfactant ions, acting as counterions to each other. In this work, a series of catanionic surfactants with the cationic quaternary ammonium group and anionic sulfate group, with variation of chain length and number of chains, have been synthesized. The results of the Langmuir pressure-area isotherms, for compression and cycles of compression-decompression, have been used to discuss the effect of length and number of hydrophobic chains on the phase behavior and molecular organization of the spread catanionic film. The molecular desorption from the catanionic film, involving either dissolution of the catanionic surfactant or desorption of the organic counterion (short chain ionic moiety), is critically discussed.