A rotational study of the AlaAla dipeptide

Abstract

Herein, we present the first rotational study of the AlaAla dipeptide, brought into the gas phase by laser ablation. Two different structures have been unveiled in the isolated environment of a supersonic expansion by Fourier transform microwave spectroscopy. These structures have been identified through their rotational and ¹⁴N quadrupole coupling constants. The flexibility of the –NH₂ and –COOH ends allows the formation of strong intramolecular interactions giving rise to five- and seven-membered ring configurations.