Hydrogen bonding, ?-? stacking and van der Waals forces-dominated layered regions in the crystal structure of 4-amino-pyridinium hydrogen (9-phosphono-non-yl)phospho-nate.

ABSTRACT: The asymmetric unit of the title mol-ecular salt, [C₅H₇N₂⁺][(HO)₂OP(CH₂)₉PO₂(OH)^-], consists of one 4-amino-pyridinium cation and one hydrogen (9-phos-phono-non-yl)phospho-nate anion, both in general positions. As expected, the 4-amino-pyridinium moieties are protonated exclusively at their endocyclic nitro-gen atom due to a mesomeric stabilization by the imine form which would not be given in the corresponding double-protonated dicationic species. In the crystal, the phosphonyl (-PO₃H₂) and hydrogen phospho-nate (-PO₃H) groups of the anions form two-dimensional O-H?O hydrogen-bonded networks in the ab plane built from 24-membered hydrogen-bonded ring motifs with the graph-set descriptor R⁶₆(24). These networks are pairwise linked by the anions' alkyl-ene chains. The 4-amino-pyridinium cations are stacked in parallel displaced face-to-face arrangements and connect neighboring anionic substructures via medium-strong charge-supported N-H?O hydrogen bonds along the c axis. The resulting three-dimensional hydrogen-bonded network shows clearly separated hydro-philic and hydro-phobic structural domains.

SUBMITTER: van Megen M 

PROVIDER: S-EPMC5050775 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature