THE ZWITTERION STRUCTURE OF IMIDAZOL-1-YLACETIC ACIDS IN THE SOLID-STATE AND IN SOLUTION

The crystal zwitterion structures of imidazol-1-ylacetic acid 1 and (/-)-3-ethoxycarbonyl-2-imidazol-1-ylpropionic acid 2 have been determi ned by X-ray diffraction analysis. Spectroscopic C-13 NMR studies in t he solid state, by the CP/MAS technique, and in solution have revealed the presence of the zwitterion structure in H2O and D2O solutions. Re sults have been complemented with O-17 NMR and IR data.