title: Charge-assisted hydrogen bonding in salts of 2-amino-1H-benzimidazole with 3-phenylpropynoic acid and oct-2-ynoic acid.
abstract: The 100 K structures of two salts, namely 2-amino-1H-benzimidazolium 3-phenylpropynoate, C7H8N3(+)·C9H5O2(-), (I), and 2-amino-1H-benzimidazolium oct-2-ynoate, C7H8N3(+)·C8H11O2(-), (II), both have monoclinic symmetry (space group P21/c) and display N-H...O hydrogen bonding. Both structures show packing with corrugated sheets of hydrogen-bonded molecules lying parallel to the [001] direction. Two hydrogen-bonded ring motifs can be identified and described with graph sets R(2)(2)(8) and R(4)(4)(16), respectively, in both (I) and (II). Computational chemistry calculations performed on both compounds show that the hydrogen-bonded ion pairs are more energetically favourable in the crystal structure than their hydrogen-bonded neutral molecule counterparts.
authors: Department of Chemistry, University of Johannesburg, PO Box 524, Auckland Park, Johannesburg 2006, South Africa.
authors: Charmaine
authors: C
authors: Arderne
authors: Department of Applied Chemistry, University of Johannesburg, PO Box 524, Auckland Park, Johannesburg 2006, South Africa.
authors: Denise K
authors: DK
authors: Olivier
authors: Department of Applied Chemistry, University of Johannesburg, PO Box 524, Auckland Park, Johannesburg 2006, South Africa.
authors: Derek T
authors: DT
authors: Ndinteh
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry*; D039301:Computers, Molecular; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D015394:Molecular Structure; D011522:Protons; D012492:Salts / Q000737:chemistry
chemical_list: C000598897:2-amino-1H-benzimidazolium oct-2-ynoate; D001562:Benzimidazoles; D011522:Protons; D012492:Salts
keywords: DFT analysis; amine/acid salts; antimicrobial properties; computational chemistry; crystal structure; ion pairs; pharmacologically active compounds