One-Dimensional Hydrogen-Bonded Structures in the 1:1 Proton-Transfer Salts of 4,5-Dichlorophthalic Acid with the Aliphatic Lewis Bases Diisopropylamine and Hexamethylenetetramine

摘要

The crystal structures of the 1:1 proton-transfer compounds of 4,5-dichlorophthalic acid with the aliphatic Lewis bases diisopropylamine and hexamethylenetetramine, viz. diisopropylaminium 2-carboxy-4,5-dichlorobenzoate (1) and hexamethylenetetraminium 2-carboxy-4,5-dichlorobenzoate hemihydrate (2), have been determined. Crystals of both 1 and 2 are triclinic, space group P - 1, with Z = 2 in cells with a = 7.0299(5), b = 9.4712(7), c = 12.790(1) angstrom, alpha = 99.476(6), beta = 100.843(6), gamma = 97.578(6)degrees (1) and a = 7.5624(8), b = 9.8918(8), c = 11.5881(16) angstrom, alpha = 65.660(6), beta = 86.583(4), gamma = 86.987(8)degrees (2). In each, one-dimensional hydrogen-bonded chain structures are found: in 1 formed through aminium N+-H center dot center dot center dot O-carboxyl cation-anion interactions. In 2, the chains are formed through anion carboxyl O center dot center dot center dot H-O-bridging water interactions with the cations peripherally bound. In both structures, the hydrogen phthalate anions are essentially planar with short intraspecies carboxylic acid O-H center dot center dot center dot O-carboxyl hydrogen bonds [O center dot center dot center dot O, 2.381(3) angstrom (1) and 2.381(8) angstrom (2)].