The Role of Small Molecules Containing Fluorine Atoms in Medicine and Imaging Applications.

The fluorine atom possesses many intrinsic properties that can be beneficial when incorporated into small molecules. These properties include the atom's size, electronegativity, and ability to block metabolic oxidation sites. Substituents that feature fluorine and fluorine-containing groups are currently prevalent in drugs that lower cholesterol, relieve asthma, and treat anxiety disorders, as well as improve the chemical properties of various medications and imaging agents.

New Diethyl Ammonium Salt of Thiobarbituric Acid Derivative: Synthesis, Molecular Structure Investigations and Docking Studies.

The synthesis of the new diethyl ammonium salt of diethylammonium(E)-5-(1,5-bis(4-fluorophenyl)-3-oxopent-4-en-1-yl)-1,3-diethyl-4,6-dioxo-2-thioxohexaydropyrimidin-5-ide 3 via a regioselective Michael addition of N,N-diethylthiobarbituric acid 1 to dienone 2 is described. In 3, the carboanion of the thiobarbituric moiety is stabilized by the strong intramolecular electron delocalization with the adjacent carbonyl groups and so the reaction proceeds without any cyclization. The molecular structure investigations of 3 were determined by single-crystal X-ray diffraction as well as DFT computations.

Substituent effects on exchange coupling: 5-Aryl-substituted semiquinones and their complexes with MnII and CuII.

A series of functionalized radical anion semiquinone (SQ-Ar) ligands and their MnII- and CuIIhydro-tris(3-cumenyl-5-methylpyrazolyl)borate (TpCum,MeMII) complexes were prepared and characterized. The semiquinone ligands have substituted phenyl rings (Ar = -C6H5NO2, -C6H5OMe, -C6H5-tert-Bu, etc.) attached to the SQ 5-position.

Design, synthesis, and properties of conformationally fixed semiquinone monoradical species.

The design of novel, functionalized semiquinone (SQ) ligands which combine structural rigidity and electron-withdrawing, electron-donating, and electroneutral substituents enables investigation of multiple structure-property relationships and building blocks for new materials, including components of sensors, switches, and molecular spintronics. Along these lines, we report the synthesis of several new SQ ligands containing fused heterocyclic ring systems. Using both electron paramagnetic resonance spectroscopy and quantum chemical calculations, we show how spin density is affected by the fused ring system substituents.