1343511-48-7Relevant academic research and scientific papers
Proton-transfer compounds of isonipecotamide with the aromatic dicarb-oxy-lic acids 4-nitro-phthalic, 4,5-dichloro-phthalic, 5-nitro-iso-phthalic and terephthalic acid
Smith, Graham,Wermuth, Urs D.
experimental part, p. o259-o264 (2011/08/09)
The structures of the 1:1 proton-transfer compounds of isonipecotamide (piperidine-4-carboxamide) with 4-nitro-phthalic acid [4-carbamoylpiperidinium 2-carb-oxy-4-nitro-benzoate, C6H13N2O 8 +·C8H4O6 -, (I)], 4,5-dichloro- phthalic acid [4-carbamoylpiperidinium 2-carb-oxy-4,5-dichloro-benzo-ate, C 6H13N2O8 +·C 8H3Cl2O4 -, (II)] and 5-nitro-isophthalic acid [4-carbamoylpiperidinium 3-carb-oxy-5-nitro-benzoate, C6H13N2O8 +·C 8H4O6 -, (III)], as well as the 2:1 compound with terephthalic acid [bis-(4-carbamoylpiperidinium) benzene-1,2-dicarboxyl-ate dihydrate, 2C6H13N 2O8 +·C8H4O 4 2-·2H2O, (IV)], have been determined at 200 K. All salts form hydrogen-bonded structures, viz. one-dimensional in (II) and three-dimensional in (I), (III) and (IV). In (I) and (III), the centrosymmetric R 2 2(8) cyclic amide-amide association is found, while in (IV) several different types of water-bridged cyclic associations are present [graph sets R4 2(8), R4 3(10), R4 4(12), R3 3(18) and R64(22)]. The one-dimensional structure of (I) features the common planar hydrogen 4,5-dichloro-phthalate anion, together with enlarged cyclic R3 3(13) and R4 3(17) associations. In the structures of (I) and (III), the presence of head-to-tail hydrogen phthalate chain substructures is found. In (IV), head-to-tail primary cation-anion associations are extended longitudinally into chains through the water-bridged cation associations, and laterally by piperidinium-carboxylate N-H...O and water-carboxylate O-H...O hydrogen bonds. The structures reported here further demonstrate the utility of the isonipecotamide cation as a synthon for the generation of stable hydrogen-bonded structures. An additional example of cation-anion association with this cation is also shown in the asymmetric three-centre piperidinium-carboxylate N-H...O,O′ inter-action in the first-reported structure of a 2:1 isonipecotamide-carboxyl-ate salt.
