title: Substituent effects on hydrogen bonding of aromatic amide-carboxylate.
abstract: N-(p-benzoyl)-anthranilic acid (BAA) derivatives have been synthesized with different substituents (X: Br, Cl, OCH3, CH3), and their crystal structures have been analyzed in order to understand the variations in their molecular geometries with respect to the substituents by using (1)H NMR, (13)C NMR, IR and X-ray single-crystal diffraction. The carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in a centrosymmetric R2(2)(8) ring motifs for BAA-Br and BAA-Cl. However, no carboxylic acid group forms classic OH⋯O hydrogen bonded dimers in BAA-OCH3 and BAA-CH3. The asymmetric unit consists of two crystallographically independent molecules in BAA-OCH3. DFT computations show that the interaction energies between monomer and dimer are in the range of 0.5-3.8kcal/mol with the B3LYP/6-31+G*, B3LYP/6-31++G*, B3LYP/6-31++G**, and B3LYP/AUG-cc-pVDZ levels of theory. The presence of different hydrogen bond patterns is also governed by the substrate. For monomeric compounds studied herein, theoretical calculations lead to two low-energy conformers; trans (a) and cis (b). Former one is more stable than latter by about 4kcal/mol.
authors.affiliation: Department of Chemistry, Faculty of Arts and Sciences, University of Balikesir, TR 10145 Balikesir, Turkey.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Sen
authors.affiliation: Department of Physics, University of Mugla Sitki Kocman, TR48000 Mugla, Turkey; Department of Physics, Faculty of Arts and Sciences, University of Balikesir, TR 10145 Balikesir, Turkey.
authors.forename: Hulya
authors.initials: H
authors.lastname: Kara
authors.affiliation: Department of Chemistry, Faculty of Arts and Sciences, University of Balikesir, TR 10145 Balikesir, Turkey; Havran Vocational School, University of Balikesir, TR 10560 Havran, Balikesir, Turkey. Electronic address: azizoglu@balikesir.edu.tr.
authors.forename: Akın
authors.initials: A
authors.lastname: Azizoglu
keywords: Computational methods; Crystal structure; DFT; Hydrogen bonding