Geometry and conformations of benzenecarboxylic acids

• Main Authors: IVAN GUTMAN, DALIBOR BADJUK, ZORAN MARKOVIC
• Format: Article
• Language: English
• Published: Serbian Chemical Society 2004-11-01
• Series: Journal of the Serbian Chemical Society
• Subjects: benzenecarboxylic acids; phthalic acid; trimesic acid; conformation; rotamer
• Online Access: http://www.shd.org.yu/HtDocs/SHD/Vol69/No11/V69-No11-06.pdf

The geometry, conformations and energy of mono-, di-, and tri-carboxylic derivatives of benzene were studied by means of the AM1 molecular-orbital method. Whereas the species having no carboxylic groups in the ortho-position (benzoic, isophthalic, terephthalic, and trimesic acids) are planar in all their (stable) conformations, those possessing carboxylic groups in the ortho-position (phthalic, 1,2,3-benzenetricarboxylic, and 1,2,4-benzenetricarboxylic acids) assume a non-planar geometry, with one carboxyl group almost orthogonal to the plane of the benzene ring. Various rotamers of each of the studied benzenecarboxylic acids have nearly the same energy.