Sodium 3-methyl-4-nitrophenolate dihydrate: a crystal engineering route towards new herringbone structures for quadratic non-linear optics Original Research Article

Sodium 3-methyl-4-nitrophenolate dihydrate (Na3M4NP) is a new stable non-linear optical crystal of Cc monoclinic symmetry. The organic anions having an average calculated molecular hyperpolarisability βxxx≈20×10−30 esu are organised in a herringbone motif, inducing, together with water molecules, a very dense packing of NaO6 edge shared octahedra. A three-dimensional network of homogeneous and short hydrogen bonds close-packs the herringbone motifs in a staggered arrangement. The crystal structure is simply described and explained in relation to basic inorganic structural models.