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 H-1, C-13, N-15 NMR spectroscopy, X-ray crystallography and DFT computations

摘要

The 2-N-allyl-1 and (3-phenyl-allyl)-2 (5-(2'-pyridyl)-[1,3,4]thiadiazol-2-yl)-amines were examined by the H-1, C-13, N-15 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. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 26]