Theoretical Study on the Conformational Equilibrium of 1’, 2' and 3'-Nitro-4-hydroxy-3-methoxy Chalcone Isomers

• Published in: Orbital : The Electronic Journal of Chemistry Vol. 13; no. 2 SI; p. 182
• Main Authors: Emiliano, Hualace Vinicius, Guaringue, Raphaela Pereira, Rozada, Thiago de Castro, Fiorin, Barbara Celania
• Format: Journal Article
• Language: English
• Published: Universidade Federal de Mato Grosso do Sul 01-06-2021
• Subjects: Analysis; Chalcones; Conformational Analysis; Density functionals; NBO; Theoretical Calculation
• ISSN: 1984-6428; 1984-6428
• DOI: 10.17807/orbital.v13i2.1548

This paper presents the conformational analysis of three chalcone compounds, 1'-nitro-4-hydroxy-3-metoxychalcone (o-CHAL), 2'-nitro-4-hydroxy-3-metoxychalcone (mCHAL) and 3'-nitro-4-hydroxy-3 metoxychalcone (pCHAL). By employing theoretical calculations, the most stable conformers of each compound were obtained. The natural bond orbital (NBO) analyses were carried out with all compounds using the Density Functional Theory (DFT) and the M06-2X method combined with the basis set 6-311++G (2d,dp) in isolated phase and indicated greater electron delocalization in s-cisconformers. The theoretical calculations provided the parameters that led to more stable s-cisin conformational equilibrium for all the isomers under investigation. However, the s-transconformer population was influenced by the position of the nitro group in the ring A, for mainly o-Chal. Keywords Conformational Analysis Chalcones Theoretical Calculation NBO