“…In solutions, the above-mentioned compounds almost always occur as a mixture of two amide conformers (E N-ë(O) -and Z N-ë(O) -conformers) of E ë=N isomer; their ratio changes with the nature of the substituents in acyl and ylidene fragments, the nature of the solvent, and the temperature [13][14][15]. In solutions, the above-mentioned compounds almost always occur as a mixture of two amide conformers (E N-ë(O) -and Z N-ë(O) -conformers) of E ë=N isomer; their ratio changes with the nature of the substituents in acyl and ylidene fragments, the nature of the solvent, and the temperature [13][14][15].…”