Bis-dicyanomethylene substituted indosquaraine: Synthesis, spectral properties, molecular and crystal structure

The aim of this work was the synthesis of two new indolenin squaraines containing one or two mal-ononitrile residues in a four-membered ring and the study of their spectral properties, molecular and crystalline structure. The geometry optimization of the substituted squaraines was carried out by the DFT/ CAM-B3LYP method. Molecular and crystal structure of new dyes has been studied by X-ray method. It has been shown that these molecules exist in the di -cis conformation. (c) 2022 Elsevier B.V. All rights reserved.