A series of new alkali metal indium iodates with isolated or extended anions.

Systematic explorations of new phases in the A(I)-In(III)-I(V)-O system by hydrothermal reactions led to five new compounds, namely, AIn(IO(3))(4) (A = Li, Na), Rb(3)In(IO(3))(6) and A(2)HIn(IO(3))(6) (A = Rb, Cs). The structure of AIn(IO(3))(4) (A = Li, Na) contains one-dimensional [In(IO(3))(4)](-) chains separated by Li(+) or Na(+) cations. In both compounds, each In(3+) cation is octahedrally coordinated by six IO(3)(-) anions, neighboring In(3+) cations are interconnected by bidentate bridging iodate anions into 1D chains. The structures of Rb(3)In(IO(3))(6) and A(2)HIn(IO(3))(6) (A = Rb, Cs) all feature isolated [In(IO(3))(6)](3-) anions with alkali metal ions (and H(+) ions) as spacers. Both optical diffuse reflectance spectrum measurements and band structure calculations based on DFT methods indicate that LiIn(IO(3))(4), NaIn(IO(3))(4), and Rb(2)HIn(IO(3))(6) are insulators.