[Al(H2O)6](IO3)2(NO3): a material with enhanced birefringence induced by synergism of two superior functional motifs

We report a new strongly birefringent material, [Al(H2O)6](IO3)2(NO3) (AINO). Based on a detailed analysis, we concluded that its enhanced birefringence (0.253 at 546 nm) predominantly resulted from a synergy of the effects of its (NO3)- and (IO3)- functional motifs, combined with an equally important and indispensable optimal arrangement of these two groups in the structure. This work has provided insight for discovering new birefringent materials.