This study was motivated by our recent observation that the analytical reagent Nitron (2) is an "instant carbene", whose reaction with coinage metal salts MX afforded complexes of its carbenic tautomer 1,4-diphenyl-3-phenylamino-1,2,4-triazol-5-ylidene (2'). Our aim was to establish an alkyl homologue of 2 in order to achieve a carbenic tautomer of higher donicity. For this purpose 1-tert-butyl...

1,2,3-Triazoles have come to the forefront as compounds of import in a vast number of applications. The fundamental properties of these species, however, remain largely unknown. Herein, the gas phase properties of 4-phenyl-1,2,3-triazole, benzotriazole, and a series of 1-phenylbenzotriazoles are described. Proton affinity and acidity values are computed and measured. Furthermore, ion-molecule r...

Solutions of sodium salicylate in anhydrous polar solvents exhibit a weak, temperature-dependent absorption band (λmax ≈ 325 nm) lying in the Stokes gap between the main absorption (296 nm) and the fluorescence band (396 nm, acetonitrile). This weak, longer wavelength absorption band is hardly observable in aqueous solution, but its intensity increases with temperature and increases with polari...

Surface-enhanced Raman scattering (SERS) spectra of a metal-complexing ligand, immobilized to a silver electrode surface, exhibits significant structural changes upon application of modest potentials. A detailed spectroscopic investigation shows that the potential applied to the electrode surface governs the tautomerization equilibrium of the immobilized ligand, p-((8-hydroxyquinoline)azo)benze...

It is well known that histidine is involved in many biological functions due to the structural versatility of its side chain. However, probing the conformational transitions of histidine in proteins, especially those occurring on an ultrafast time scale, is difficult. Herein we show, using a histidine dipeptide as a model, that it is possible to probe the tautomer and protonation status of a hi...

Adsorption of 4-imidazolemethanol (ImMeOH) on a copper electrode has been investigated by in situ isotope-edited (H/D and (63)Cu/(65)Cu) surface enhanced Raman spectroscopy (SERS) in aqueous solutions at physiological pH (7.0) in a potential window from -0.500 to -1.100 V. Theoretical modeling by DFT calculations at the B3LYP/6-311++G(d,p) level for light atoms and LANL2DZ with ECP for copper a...

Ureido pyrimidinedione derivatives with phenyl, 1-naphthyl and 2-naphthyl substituents form stable dimers via quadruple hydrogen bonding, but the 1-naphthyl derivative presents an unexpected tautomer in the solid state.