Rational Design of Noncentrosymmetric Organic–Inorganic Hybrids with a π-Conjugated Pyridium-Type Cation for High Nonlinear-Optical Performance
Limei Zhang, Xinyuan Zhang, Fei Liang, Zhanggui Hu, Yicheng Wu
Abstract
Organic–inorganic hybrid materials have attracted increasing attention due to their unique superiority by combining the features of organic parts with inorganic parts. Herein, two organic–inorganic hybrid nonlinear-optical crystals, [C 5 H 6 O 2 N 3 ] 2 [IO 3 ] 2 ( I ) and [C 5 H 6 O 2 N 3 ][HSO 4 ]·H 2 O ( II ), were successfully synthesized in aqueous solution by selecting 2-amino-3-nitropyridine as the cation and different anions of [IO 3 ] − and [HSO 4 ] − . The two compounds crystallized in the noncentrosymmetric space groups of P 2 1 and P 2 1 2 1 2 1, respectively. I displays second-harmonic-generation (SHG) effects of 2.4 × KDP (KH 2 PO 4 ) and a large birefringence (Δ n cal ∼ 0.22). Moreover, II exhibits a stronger SHG response of 5.2 × KDP, an enhanced band gap (2.81 eV), as well as a large birefringence (Δ n cal ∼ 0.25). This work points out a new feasible path for the rational design of high-performance organic–inorganic hybrid materials.