Abstract Tautomerism is one of the most important phenomena to consider when designing biologically active molecules. In this work, we use NMR spectroscopy, IR, and X-ray analysis as well quantum-chemical calculations in gas phase a solvent study tautomerism 1- (2-, 3- 4-pyridinecarbonyl)-4-substituted thiosemicarbazide derivatives. The tautomer containing both carbonyl thione groups turned out...

A novel alkyl chain-functionalized manganese complex with dioxolene ligands shows a bimodal three-membered valence tautomerism, one of which synchronizes with a cooperative solid-melt phase transition and the other occurs in the melt noncooperatively.

We report a state-of-the-art spectroscopic study of an archetypical barbaralone, conclusively revealing the valence tautomerism phenomena for this bistable molecular system. The two distinct 1- and 5-substituted tautomers have been isolated in supersonic expansion first time successfully characterized by high-resolution rotational spectroscopy. This work provides irrefutable experimental eviden...

The glyceraldehyde conversion in terms of dehydration, keto-enol tautomerism, and retro-aldol reaction has been discussed by means of ab initio density functional theory calculation to elucidate the catalytic water molecule influence on the pathways. The optimized structures of reactants, products, and transition state structure on the glyceraldehyde conversion pathways were fully optimized wit...

A novel lanthanide molecular cluster pair (MCP), displaying single molecule magnet behaviour, was assembled using the novel o-vanilloyl hydrazone ligand, versatile in terms of denticity, tautomerism and the rotatable C-C bond.

We explore tautomerism and its consequences in the first example of diamino-benzoquinonediimine bearing both electron-donating electron-withdrawing groups on same 6-? electron subunit.

Knowledge about tautomer forms of a structure is important since, e.g., a property prediction for a molecule can yield to different results which depend on the individual tautomer. Tautomers are isomers that can be transformed to each other through chemical equilibrium reactions. In this paper the first exact Branch-and-Bound (B&B) algorithm to calculate tautomer structures is proposed. The alg...

A potential end-point in the miniaturization of electronic devices lies in the field of molecular electronics, where molecules perform the function of single components. To date, hydrogen tautomerism in unimolecular switches has been restricted to the central macrocycle of porphyrin-type molecules. The present work reveals how H-tautomerism is the mechanism for switching in substituted quinone ...

Tautomerism in organic chemistry has been extensively studied in condensed phase by spectrometric methods, mainly by IR and NMR techniques. Mass spectrometry studies start 40 years ago but just recently it has been recognized the importance of the mass spectral data for the study of tautomerism in the gas phase. Mass spectrometry can provide valuable information in regard to tautomeric equilibr...