Now showing items 1-10 of 15
Neutral organic redox pairs based on sterically hindered hydroquinone/benzoquinone derivatives for dye-sensitized solar cells
Substituted derivatives of hydroquinone/benzoquinone were studied as organic redox mediators in the electrolyte for dye-sensitized solar cells (DSSCs). Thus, di-tert-butylhydroquinone (DTHQ), thymohydroquinone (ThymHQ) and ...
Reactivity and structure of derivatives of 2-hydroxy-1,4-naphthoquinone (lawsone)
The structures of two derivatives of 2-hydroxy-1,4-naphthoquinone (lawsone) are examined using the density functional theory (DFT) hybrid functional B3LYP. Using the optimized structure of lawsone acetate, the reactivity ...
Synthesis of 2-hydroxy-3-substituted naphthoquinones using the Heck reaction
An efficient Heck coupling of 2-hydroxy-3-iodo-naphthoquinone with a series of electron-deficient alkenes in aqueous solution has been accomplished. The method is characterized by simple conditions and facile work-up to ...
Grids III: Hydrogen Bridges in Introductory Chemistry
Cuadrículas III: Puentes de Hidrógeno en Química General
Based on IUPAC recommendations for the definition of the hydrogen bond, a series of grids is presented to provide instructors of introductory chemistry courses with visual examples of H-bridged systems. The grids ...
General Chemistry Without Orbitals
We illustrate the solutions of Schroedinger's equation for the hydrogen atom in coordinates of all four systems, and differentiate the applicability of orbitals in these four systems. We present reasons that future textbooks ...
Synthesis of Iodinated Naphthoquinones Using Morpholine-Iodine Complex
(Synthetic Communications Vol. 34, No. 18, pp. 3389–3397, 2004, 2004)
The efficient synthesis of 2‐hydroxy‐3‐iodo‐1,4‐naphthoquinone (3), 2‐amino‐3‐iodo‐1,4‐naphthoquinone (4), and 2‐iodo‐1,4‐naphthoquinone (5) have been developed using the parent naphthoquinone in combination with the ...
Grids II: Aromatic Acidity and Basicity
Cuadrículas II: Acidez y Basicidad Aromática
The effect of substituents on the acidity of benzoic acids and basicity of anilines has been organized in grids to demonstrate the inductive and resonance effects. The relation between structure and pKa is emphasized ...
Orbitals in general chemistry, Part III: Consequences for Teaching
In Part III of this series, we undertake a critique of the nature of application of orbitals to describe or to explain the structure and the binding within molecules and materials. Teaching orbitals in introductory chemistry ...
Orbitals in general chemistry, Part II: Mathematical Realities
In Part II of a three-part series, we discuss two factors absent from textbooks of general chemistry that are important in a discussion of teaching orbitals. First, atomic orbitals are shown systematically to comprise ...
Crystal structure of (E)-2-(tert-butylamino)-4-(tertbutylimino)naphthalen-1(4H)-one
The title compound, C18H24N2O, is the first example of a naphthoquinone imine derivative isolated in the 4-imine/2-amine tautomeric form having bulky alkyl substituents at the N atoms. The molecular conformation is stabilized ...