Herein, we report an unprecedented asymmetric guanidinium polyiodate, namely, C­(NH2)3(I3O8)­(HI3O8)­(H2I2O6)­(HIO3)4·3H2O (1). The title compound was obtained via the hybridization of polyiodate anions and planar π-conjugated C­(NH2)3 +; meanwhile, its strong second-harmonic-generation (SHG) response (2.1 × KDP, where KDP = KH2PO4) and wide band gap (3.89 eV) were mainly dominated by the synergy effect of the aforementioned structural units.

We herein report a mixed organic cationic hybrid nitrate, namely, [C(NH 2 ) 2 NHNO 2 ][C(NH 2 ) 3 ](NO 3 ) 2 (1). It was successfully achieved via combining three different planar groups: [(C(NH 2 ) 2 NHNO 2 ] + , C(NH 2 ) 3 +