Two-Dimensional Layers Using Different Combinations of Hydrogen Bonded Rings in Three Ammonium Carboxylate Salts

Abstract

The crystal structure of the ammonium carboxylate salts (cyclohexylammonium)2·(terephthalate) (1), (cyclohexylammonium)2·(trans-1,4-cyclohexanedicarboxylate) (2) and (cyclododecylammonium)2·(trans-1,4-cyclohexanedicarboxylate) (3) were determined by low temperature single crystal X-ray diffraction. The molecular salts were prepared by solution crystallization of the carboxylic acids with the respective amines in a 1:2 stoichiometric ratio. The crystal structure of 1 belongs to the monoclinic space group Cc with a = 11.5643(7) A, b = 22.8180(13) A, c = 8.4163(5) A and β = 117.020(2)°. The crystal structure of 2 belongs to the monoclinic space group P21/n with a = 16.9546(10) A, b = 6.4352(4) A, c = 19.3948(12) A and β = 94.677(4)°. The crystal structure of 3 belongs to the monoclinic space group P21/c with a = 8.1714(5) A, b = 34.3887(17) A, c = 11.0230(6) A and β = 95.790(4)°. The changes in cation and anion species produces three distinct types of layers, with corresponding changes in the hydrogen bonded ring patterns linking the ionic species together using charge-assisted N+–H···O− hydrogen bonds. The crystal structures of three ammonium carboxylate salts are determined and all form 2-D layers by virtue of having two carboxylate functional groups on their anion molecules.