Synthesis and crystal structure of a new stilbazolium salt with large second-order optical nonlinearity

The novel stilbazolium salt 4-N,N-dimethylamino- 4'-N'-methyl-stilbazolium 2-naphthalenesulfonate (DSNS), has been synthesized and small single crystals were grown. The crystal structure of the resulting crystals was determined via X-ray crystallography and it was found to be non-centrosymmetric with the chromophores aligned perfectly parallel. The Kurtz powder test of the crystals at lambda = 1.9 mm reveals that they have around 50 percent higher second-order nonlinearity than the presently best organic nonlinear optical crystal 4-N, N-dimethylamino-4'-N'-methyl-stilbazolium tosylate ( DAST).