The proton transfer in the isolated, mono and dehydrated forms, isolated dimers of N-Hydroxy Methylen Formamide (NHMF) have been completely investigated in the present study using Density Functional Theory (DFT), Möller-Plesset perturbation (MP2) and Hartree-Fock (HF) methods with the 6-31G and 6-311G basis sets. The barrier heights for both H2O-assisted and auto-assistance reactions are signif...

Synthetic approaches to the VANOL and VAPOL ligands are developed which are straightforward, inexpensive, efficient, and amenable to large-scale preparation of the ligands since minimum chromatographic purification is required. The key step in each synthesis is a cycloaddition/electrocyclic ring-opening/electrocyclic ring closure/tautomerization cascade that provides a direct one-step route to ...

Using ambient atmosphere instead of pure nitrogen environment enabled efficient recording of room temperature fluorescence from single molecules of porphycenes, chromophores with a high triplet formation efficiency. Double hydrogen transfer between two chemically identical trans tautomers has been demonstrated for parent porphycene and three alkyl derivatives by the analysis of spatial patterns...

The electrochemical cathodic reduction of cyclic imides (maleimides) to succinimides can be achieved chemoselectively in the presence of alkene, alkyne, and benzyl groups. The efficiency of the system was demonstrated by using a 3D electrode in a continuous flow reactor. The reduction of 3,4-dimethylmaleimides to the corresponding succinimides proceeds with a 3:2 diastereomeric ratio, which is ...

1,1-Divinyl-2-phenylcyclopropanes are entry points to a rich area of rearrangement chemistry. With N,N-diallyl amide substrates, tandem radical cyclizations can be initiated at room temperature. Warming provides products of pure thermal rearrangements with acids, ester, and amides. These isomerizations give vinylcyclopentenes resulting from divinylcyclopropane rearrangements and more deeply rea...

Oxybenzone is a common constituent of many commercially available sunscreens providing photoprotection from ultraviolet light incident on the skin. Femtosecond transient electronic and vibrational absorption spectroscopies have been used to investigate the nonradiative relaxation pathways of oxybenzone in cyclohexane and methanol after excitation in the UVA region. The present data suggest that...

The resonance theory is still very useful in understanding the valence electron structure. However, such a viewpoint not usually obtained by general-purpose quantum chemical calculations, instead requires rather special treatment as bond methods. In this study, we propose method based on second quantization to analyze results calculations from local point of view electronic structure and diazad...

The Old Yellow Enzyme has been shown to catalyze efficiently the NADPH-linked reduction of nitro-olefins. The reduction of the nitro-olefin proceeds in a stepwise fashion, with formation of a nitronate intermediate that is freely dissociable from the enzyme. The first step involves hydride transfer from the enzyme-reduced flavin to carbon 2 of the nitro-olefin. The protonation of the nitronate ...

We investigate the engraving of spectral holograms in porphyrin-derivative-doped solids, where a tautomerization process gives rise to persistent spectral hole burning at low temperature. Starting with a microscopic model of this process, we build a theory that connects conventional narrow-band hole burning with the engraving and retrieval of broadband holograms, in samples with possibly large ...

The title compound [systematic name: 3-hy-droxy-2-(4-methyl-sulfonyl-2-nitro-benzo-yl)cyclo-hex-2-enone], C14H13NO7S, is the enol form of a benzoyl-cyclo-hexa-nedione herbicide. As a result of this tautomerization, there is intra-molecular O-H⋯O hydrogen bond enclosing an S(6) ring motif. The cyclo-hexene ring has an envelope conformation, with the central CH2 C atom as the flap. Its mean plane...