Related Experiment Video
Updated: Mar 23, 2026

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Crystal structure of 2,6-di-amino-pyridinium chloride
Matthias Mastalir1, Martina Schroffenegger1, Berthold Stöger2
1Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, A-1060 Vienna, Austria.
Abstract:
The asymmetric unit of the title salt, C5H8N3 (+)·Cl(-), comprises one half of the 2,6-di-amino-pyridinium cation (the other half being completed by the application of mirror symmetry) and one Cl(-) counter-anion, also located on the mirror plane. The amino N atom shows a significant pyramidalization, with a dihedral angle of 30.4 (14)° between the least-squares planes of the amino group and the non-H atoms of the 2,6-di-amino-pyridinium moiety. In the crystal, the cationic mol-ecules and Cl(-) counter-anions are arranged in sheets parallel to (001) consisting of alternating polar and non-polar parts associated with the the Cl(-) anions, pyridinium and amino moieties, and the pyridine rings, respectively. N-H⋯Cl inter-actions within the polar part, as well as slipped π-π inter-actions in the non-polar part, help to establish the three-dimensional network.
More Related Videos
06:35Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
09:16X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects
Published on: June 8, 2016
Related Concept Videos
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Unit Cells
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Structure of Amines
Determination of Crystal Structures
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...