Solid-state cyclization of Ala–Leu and Leu–Ala dipeptides, and self-assembly and luminescent properties of the cyclic dipeptide

Abstract

New biocompatible luminescent materials based on cyclic dipeptides were prepared. For this, the thermal properties of dipeptides L-alanyl–L-leucine and L-leucyl–L-alanine and the kinetics of their cyclization in the solid-state upon heating are studied for the first time. Using isoconversion kinetics approaches, the kinetic parameters of the reactions and the models describing these processes are determined. The influence of the amino acid residue sequence in dipeptide molecules on their thermal properties and the activation energy of the cyclization reaction is discussed. A way to control the self-assembly of a cyclic dipeptide to obtain various ordered structures is demonstrated. The microstructures of the cyclic dipeptides have luminescent properties and can be used in optical devices.