2-AMINO-5-NITROPYRIDINIUM MONOHYDROGENPHOSPHITE

The crystal structure of this new 2-amino-5-nitropyridinium salt consi sts of centrosymmetric double layers built up with C5H6N3O2+ cations a nd H2PO3- phosphite anions. The main feature of this stacking is the p resence of centrosymmetric (H4P2O6)2- clusters holding both layers tog ether through relatively strong hydrogen bonds. Weaker hydrogen bonds maintain the cohesion of the organic-inorganic arrangement within a la yer. Direct bonding exists neither between the organic entities, nor b etween the double layers. The dimension charge compromise of the anion ic group is not favourable for inducing a polar packing of cations whi ch would be necessary to originate nonlinear optical properties.