Ferroelectric Alignment Of Nlo Chromophores In Layered Inorganic Lattices: Structure Of A Stilbazolium Metal-Oxalate From Powder Diffraction Data

The structure of the organic:inorganic layered material DAZOP[MnCr(ox)(3)](.)0 . 6CH(3)CN [DAZOP = 4-(4-dimethylamino-phenylazo)-1-methyl-pyridinium, which has 61 independent atoms in the asymmetric unit, has been solved from laboratory powder X-ray diffraction data using a novel real-space simulated annealing approach. The stilbazolium. chromophores adopt a ferroelectric. arrangement between the layers of the two-dimensional metal-oxalate system, giving rise to a material that is NLO active and orders ferromagnetically at 6 K. The factors leading to the favorable alignment of the chromophores are discussed.