The reaction of cerium(IV) ammonium nitrate (CAN) with a range of N-(p-anisyl)azoles in acetonitrile or methanol solvents leads to N-dearylation releasing the parent NH-azole and p-benzoquinone in comparable yields. The scope and limitations of the reaction are explored. It was successful with 1-(p-anisyl)pyrazoles, 2-(p-anisyl)-1,2,3-triazoles, 2-(p-anisyl)-2H-tetrazoles, and 1-(p-anisyl)penta...

IR spectroscopy of nucleobases in the gas phase reflects simultaneous advances in both experimental and computational techniques. Important properties, such as excited state dynamics, depend in subtle ways on structure variations, which can be followed by their infrared signatures. Isomer specific spectroscopy is a particularly powerful tool for studying the effects of nucleobase tautomeric for...

5-Furan-2-yl[1,3,4]oxadiazole-2-thiol (Ia) and 5-furan-2-yl-4H-[1,2,4]-triazole-3-thiol (Ib) were synthesized from furan-2-carboxylic acid hydrazide. Mannich bases and methyl derivatives were then prepared. The structures of the synthesized compounds were confirmed by elemental analyses, IR and (1)H-NMR spectra. Their thiol-thione tautomeric equilibrium is described.

The mol-ecule of the title compound, C(27)H(24)N(4)O(5), exists in the keto-enamine tautomeric form, stabilized by an intra-molecular N-H⋯O hydrogen bond. An intra-molecular C-H⋯·O hydrogen bond also occurs. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into chains.

Tautomeric switching is observed in a series of benzimidazole-based anion receptors upon addition of basic anions. An N-methylbenzimidazole based receptor selectively interacts with dihydrogen phosphate over a variety of other putative anionic guests via a combination of donated and accepted hydrogen bonds.

The title compound, C(16)H(17)NO, is a Schiff base which adopts the phenol-imine tautomeric form in the solid state. The mol-ecule is almost planar, with a dihedral angle of 4.61 (4)° between the aromatic rings. The molecular structure is stabilized by an intramolecular O-H⋯N hydrogen bond which generates a six membered ring.

An elusive free 4-(isopropylamino)imidazol-2-ylidene is engaged in a tautomeric equilibrium with its mesoionic tautomer, 4-(isopropylamido)imidazolium, which displays the typical reactivity of a cyclic diaminocarbene; once coordinated to a Rh(I) centre, it undergoes a smooth 4e(-) oxidation of its backbone to yield an amido-amidino-carbene, a weak electron donor viable only in its complexed form.

In the title compound, C(14)H(12)BrNO, is a Schiff base which adopts the phenol-imine tautomeric form in the solid state. The dihedral angle between the two aromatic rings is 34.26 (9)° and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring.