Acta Crystallographica Section B

Structural Science

Volume 57, Part 2 (April 2001)

research papers

Acta Cryst. (2001). B57, 201-212 [ doi:10.1107/S010876810001853X ]

Salts of 3,5-dinitrobenzoic acid with organic diamines: hydrogen-bonded supramolecular structures in one, two and three dimensions

C. J. Burchell, C. Glidewell, A. J. Lough and G. Ferguson

Abstract: The trigonally trisubstituted carboxylic acid 3,5-dinitrobenzoic acid, (O₂N)₂C₆H₃COOH, forms 2:1 salts with a range of organic diamines L, with the general composition [LH₂]²⁺·[{(O₂N)₂C₆H₃COO}^-]₂. When L is a bis-tertiary amine the hard N-HO hydrogen bonds generate finite three-component aggregates, anioncationanion, and these aggregates are further linked by soft C-HO hydrogen bonds to form one-dimensional molecular ladders when L is N,N,N',N''-tetramethyl-1,2-diaminoethane and chains of rings when L is 4,4'-dipyridylethane or 4,4'-dipyridylethene; two-dimensional sheets are formed when L is 1,4-diazabicyclo[2.2.2]octane and a three-dimensional framework is formed when L is N,N'-dimethylpiperazine. When L is the bis-secondary amine piperazine, the hard N-HO and soft C-HO hydrogen bonds each generate continuous motifs in the form of distinct chains of rings, the combination of which generates sheets, while when L is the bis-primary amine 1,2-diaminoethane the hard N-HO hydrogen bonds alone generate a three-dimensional framework.

Keywords: salts; supramolecular; three dimensions; hydrogen bonding.