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The intramolecular hydrogen bonding in the series of 4,6-dihaloresorcinols (with halogen atoms being F, Cl, Br, or I) is believed to play a noticeable role in determining the structural and electronic aspects. All theoretical levels employed in this work suggested that the intramolecular O–H...X-C bonding greatly stabilizes the anti (A) configuration that is at least 5 kcal/mol more stable than the syn (S) form, where such an interaction is absent. Vibrational spectroscopic examination of the OH stretching and bending modes suggested that the dibromo derivative encounters a relatively greater extent of intramolecular hydrogen bonding interaction compared to the corresponding molecules, which is in agreement with the ab initio MP4(SDQ) results. The A ↔ AS ↔ S interconversion barriers were predicted to be in the range of 5–10 kcal/mol, with the difluoro derivative corresponding to the smallest energy barriers in the series in the gas phase. The order of the frontier molecular orbitals and electrostatic potential maps showed a consistent correlation with the size and mass down the halogen group. The calculated infrared and Raman wavenumbers were compared with the experimentally observed ones to assist systematic assignments of the vibrational modes. Molecular docking analysis suggested that the difluoro derivative shall be a potent halo-substituted resorcinol candidate in the treatment of specific types of skin inflammation. [ABSTRACT FROM AUTHOR]

Pyrite scale formation is a critical problem in the hydrocarbon production industry; it affects the flow of hydrocarbon within the reservoir and the surface facilities. Treatments with inorganic acids, such as HCl, results in generation toxic hydrogen sulfide, high corrosion rates, and low dissolving power. In this work, the dissolution of pyrite scale is enhanced by the introduction of electrical current to aid the chemical dissolution. The electrolytes used in this study are chemical formulations mainly composed of diethylenetriamine-pentaacetic acid–potassium (DTPAK5) with potassium carbonate; diethylenetriamine pentaacetic acid sodium-based (DTPANa5), and l-glutamic acid-N, N-diacetic acid (GLDA). DTPA and GLDA have shown some ability to dissolve iron sulfide without generating hydrogen sulfide. The effect of these chemical formulations, disc rotational rate and current density on the electro-assisted dissolution of pyrite are investigated using Galvanostatic experiments at room temperature. The total iron dissolved of pyrite using the electrochemical process is more than 400 times higher than the chemical dissolution using the same chelating agent-based formulation and under the same conditions. The dissolution rate increased by 12-folds with the increase of current density from 5 to 50 mA/cm2. Acid and neutral formulations had better dissolution capacities than basic ones. In addition, doubling the rotational rate did not yield a significant increase in electro-assisted pyrite scale dissolution. XPS analysis confirmed the electrochemical dissolution is mainly due to oxidation of Fe2+ on pyrite surface lattice to Fe3+. The results obtained in this study suggest that electro-assisted dissolution is a promising technique for scale removal. [ABSTRACT FROM AUTHOR]

Structural and vibrational properties of resorcinol, its -OD isotopomer and dianion salt were compared with the help of quantum-chemical and spectroscopic techniques. The relative stability computed at the MP4/6-311++G(d,p) level predicted that the syn-syn rotameric form of the resorcinol molecule is about 0.7 kcal/mol higher in energy than the more stable anti-syn and anti-anti forms. Vibrational frequencies calculated for the optimized α-resorcinol and its -OD isotopomer unit cells showed that out-of-plane bending vibrations tend to shift to higher wavenumbers for the solid phase compared to the non-condensed phase indicating strong intermolecular packing forces. OH/OD isotopic shifts were identified for stretching and binding modes, which supported by DFT findings. Infrared, Raman and proton NMR data confirmed a notable change in the overall electronic properties of resorcinol upon the abstraction of the hydroxyl protons. In addition, resorcinol, in its three rotameric configurations, exhibited a stable complexation with keratin-7. While the highly electronegative nature of oxygen atoms contributed effectively to the binding affinity of resorcinol towards keratin-7, careful docking analysis showed that the steric factor play the major role in the keratolytic activity of resorcinol. [ABSTRACT FROM AUTHOR]