α- and β-(C<sub>4</sub>H<sub>5</sub>N<sub>2</sub>O)(IO<sub>3</sub>)·HIO<sub>3</sub>: Two SHG Materials Based on Organic–Inorganic Hybrid Iodates
Qianqian Chen, Chun‐Li Hu, Mingzhi Zhang, Bingxuan Li, Jiang‐Gao Mao
Abstract
Organic–inorganic hybrid nonlinear optical (NLO) materials are highly anticipated because of the integration of both merits of the organic and inorganic moieties. Herein, the 2-pyrimidinone cation (C 4 H 5 N 2 O) + has been incorporated into the iodate system to form two polymorphic organic–inorganic hybrid iodates, namely, α- and β-(C 4 H 5 N 2 O)(IO 3 )·HIO 3 . They crystallize in different polar space groups ( Ia and Pca 2 1 ), and their structures feature one-dimensional (1D) chain structures composed of (C 4 H 5 N 2 O) + cations, IO 3 – anions, and HIO 3 molecules interconnected via hydrogen bonds. α- and β-(C 4 H 5 N 2 O) (IO 3 )·HIO 3 exhibit strong and moderate second-harmonic-generation (SHG) responses of 6.4 and 0.9 × KH 2 PO 4 (KDP), respectively, the same band gaps of 3.65 eV, and high powder laser-induced damage threshold (LIDT) values [51 and 57 × AgGaS 2 (AGS)]. The results of theoretical calculations revealed that the large SHG effect of α-(C 4 H 5 N 2 O)(IO 3 )·HIO 3 originated from the IO 3 and HIO 3 groups. This work indicates that (C 4 H 5 N 2 O) + is a potential group for designing new NLO materials with brilliant optical performances.