Acentric La 3 (IO 3 ) 8 (OH) and La(IO 3 ) 2 (NO 3 ): Partial Substitution of Iodate Anions in La(IO 3 ) 3 by Hydroxide or Nitrate Anion.

Partial substitution of iodate anions in La(IO3 )3 by OH- or NO3 - anion led to acentric La3 (IO3 )8 (OH) and chiral La(IO3 )2 (NO3 ). The structure of La3 (IO3 )8 (OH) can be seen as a complex three-dimensional (3D) network composed of two-dimensional [La3 (IO3 )2 (OH)]6+ cationic layers that are further bridged by remaining iodate anions, or alternatively as a 3D network composed of one-dimensional [La3 (IO3 )6 (OH)]2+ cationic columns being further interconnected by additional iodate anions, while the structure of La(IO3 )2 (NO3 ) can be seen as a novel 3D structure with planar NO3 groups serving as linkage between the [La3 (IO3 )6 ]3+ triple layers. Compared to La(IO3 )3 , both compounds show considerably wide band gaps and enhanced thermal stability. La(IO3 )2 (NO3 ) shows a moderate second harmonic generation (SHG) response of ∼0.6 times that of KDP (KH2 PO4 ), a wide band gap of 4.23 eV, and a high LDT value (22 × AgGaS2 ). Optical property measurements, thermal analysis, as well as theoretical calculations on SHG origin, were performed. It can be deduced that partial substitution of iodate anions can be a facile route to design new noncentrosymmetric metal iodates with novel structure and potential application.