The Studies of Structure of 2N‐(3‐phenyl‐allyl‐)(5‐phenyl‐[1,3,4] Thiadiazol‐2‐yl) Amine in Solution

Abstract

2N‐(3‐phenyl‐allyl‐)(5‐phenyl‐[1,3,4] thiadiazol‐2‐yl) amine was studied by means of the 1H, 13C, 15N NMR spectroscopy and DFT calculations. On the basis of the one‐dimensional 1H, 13C, 15N‐NMR and two‐dimensional 1H‐13C HMQC, 1H‐13C HMBC, 1H‐15N HMQC, 1H1H NOESY, 1H1H COSY correlation spectra the amine‐type and the imine‐type tautomers have been determined in the solution. Variety of structural forms including: biradical, ionic–biradical, and ionic structures of the amine‐type a and of the imine‐type b, c tautomers exist in the solution. According to the DFT computations the differences in the total energy between a and b, a and c, and b and c tautomers are equal to 1.5 kJ/mol, 1.2 kJ/mol, and 0.3 kJ/mol, respectively.