STRUCTURAL STUDY OF 2-AMINO-5-NITROPYRIDINE AND 2-AMINO-3-NITROPYRIDINE - INTERMOLECULAR FORCES AND POLYMORPHISM

The crystal structures of four compounds from a family of commonly use d molecular building blocks of nonlinear optical materials, aminonitro pyridines, have been determined. The structures of 2-amino-5-nitropyri dine 1, 2-amino-5-nitropyridine monohydrate 2, and of two new polymorp hs of 2-amino-3-nitropyridine 3,4, are all stabilised by a combination of hydrogen bonds (including C-H ... X interactions) and dispersive a nd electrostatic interlayer interactions. The balance between these in termolecular forces, and the way in which they influence the packing o f these materials, are discussed.