The structure of N-allyl derivatives of (5-(2′-pyridyl)-[1,3,4]thiadiazol-2-yl) amine in solution and the solid state studied by the 1H, 13C, 15N NMR spectroscopy, X-ray crystallography and DFT computations

Abstract

The 2-N-allyl- 1 and (3-phenyl-allyl)- 2 (5-(2′-pyridyl)-[1,3,4]thiadiazol-2-yl)-amines were examined by the 1H, 13C, 15N NMR spectroscopy, X-ray diffraction and B3LYP/6-31G(d, p) computations. It has been found that all compounds exist in the egzo–amino tautomeric form a in a solution and in a solid state. Two different positions of the H6 atom have been found in the crystals, enabling formation of the polar ribbons 1 and the centrosymmetric dimers 2. The DFT calculations have shown the egzo–amino tautomeric form to be more stable than the egzo–imino form by 35 kJ/mol.