Specific Features of Intramolecular Proton Transfer Reaction in Schiff Bases

Author: Koll Aleksander  

Publisher: MDPI

E-ISSN: 1422-0067|4|7|434-444

ISSN: 1422-0067

Source: International Journal of Molecular Sciences, Vol.4, Iss.7, 2003-06, pp. : 434-444

Access to resources Favorite

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

The differences between the intramolecular proton transfer in Mannich and Schiff bases are discussed. The tautomeric forms being in equilibrium in both types of molecules are seriously different. In Mannich bases there are in equilibrium the forms of phenols and phenolates. In Schiff bases each of tautomers is strongly influenced by resonance between zwitterionic and keto structures. Despite the common opinion that the proton transfer forms in compounds with internal π-electronic coupling are mainly keto forms it is shown in this work, that in Schiff bases the content of keto structure is slightly less than zwitterionic one. Almost equal participation of both forms leads to effective resonance between them and stabilization of intramolecular hydrogen bond in this way.

Related content