Determination of primordial radionuclide concentrations in UAE groundwater using high-resolution gamma-ray spectrometry

Journal of Radioanalytical and Nuclear Chemistry - Groundwater is the most valuable resource in arid regions, such as UAE. Estimations of natural radionuclide concentrations are important to...     

Determining the Tensile Properties and Dispersion Characterization of CNTs in Epoxy Using Tem and Raman Spectroscopy

Mechanics of Composite Materials - In this work, transmission electron microscopy (TEM) and Raman spectroscopy were used to assess the dispersion quality of carbon nanotubes (CNTs) in an epoxy...     

Solvent and structural effects in tautomeric 3-cyano-4-(substituted phenyl)-6-phenyl-2(1H)-pyridones: experimental and quantum chemical study

The tautomeric equilibria between 2-pyridone and 2-hydroxypyridine forms of methoxy, chloro, and nitro derivatives of 3-cyano-4-(2-, 3-, and 4-substituted phenyl)-6-phenyl-2(1H)-pyridones were evaluated from UV/Vis spectral data. Linear solvation energy relationships of Kamlet–Taft and Catalán-rationalized solvent have influence on tautomeric equilibria. Transmission of substituent effect was analyzed by the Hammett equation. Quantum chemical calculations were performed by density functional theory (B3LYP). The experimental data were interpreted with the aid of time-dependent density functional method. Electron density distribution was analyzed by Bader’s analysis. It was found that substituents of different electronic properties change the extent of conjugation, and affect intramolecular charge transfer character. Theoretical calculations and experimental results gave insight into the influence of the molecular conformation on the transmission of substituent effects, as well as on contribution of different solvent–solute interactions.