Noncovalent Assembly Engineering Achieves Excellent Birefringence in Crystals
Birefringent crystals can manipulate the phase and polarization of light, and are therefore widely used as key components in various optical devices. In this study, the hydrogen-bonding interactions between the [C<sub>8</sub>H<sub>6</sub>FN<sub>2</sub>O]<sup>+</sup> donor and the anionic acceptors, namely [SiF<sub>6</sub>]<sup>2-</sup> and Cl<sup>-</sup>, were utilized to achieve a high degree of coplanarity during crystal packing. The as-grown (C<sub>8</sub>H<sub>6</sub>FN<sub>2</sub>O)<sub>2</