A structural study of 2-amino-5-nitropyridine and 2-amino-3-nitropyridine: intermolecular forces and polymorphism

Abstract

The crystal structures of four compounds from a family of commonly used molecular building blocks of nonlinear optical materials, aminonitropyridines, have been determined. The structures of 2-amino-5-nitropyridine 1, 2-amino-5-nitropyridine monohydrate 2, and of two new polymorphs of 2-amino-3-nitropyridine 3,4, are all stabilised by a combination of hydrogen bonds (including C–H‥X interactions) and dispersive and electrostatic interlayer interactions. The balance between these intermolecular forces, and the way in which they influence the packing of these materials, are discussed.