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 simulate d 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.