Abstract
Charge-transfer (CT) interaction of two artificial sweeteners, aspartame(Asp) and neotame (Neo), with three organic p-acceptors was investigated by UV-visible and Infrared (IR) spectrophotometric measurements. The target sweeteners interacted with the 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), chloranilic acid (CA), and picric acid (PA) molecules in methanol solvent at room temperature. Spectral results suggest that the unshared electron pair of nitrogen atoms (-NH2 in Asp molecule, and -NH in Neo molecule) donate electronic charge to the aromatic ring of the acceptor (Asp -> acceptor; Neo -> acceptor) forming the CT complex via a n -> pi* transition. The 1:1 Benesi-Hildebrand method was used to calculate several spectroscopic data, such as the formation constant (KCT) and the molar extinction coefficient (epsilon(max)), and other physical parameters. The correlation test indicates strong relationships among several of the physical parameters. (C) 2021 Elsevier B.V. All rights reserved.