Syntheses, structures, and characterization of two new rubidium cadmium(II)/zinc(II) borates: Rb3MB5O10 (M = Cd, Zn).

Two new ternary borates, Rb₃MB₅O₁₀ (M = Zn, Cd) have been synthesized by solid-state reactions, and their structures were determined by single-crystal X-ray diffraction. They crystallize in the same monoclinic space group P2_1/n with lattice constants a = 10.449(11) A˚ , b = 9.414(10) A˚ , c = 11.690(12) A˚ , and b = 105.888(11)º for Rb3ZnB5O10, while a = 7.6391(5)A˚ , b =19.2304(13)A˚ , c = 7.6905(5)A˚ , and β = 116.698(4)º for Rb₃CdB₅O₁₀. And their crystal structures both contain the interesting two-dimension (2D) infinite [MB₅O₁₀]1_∞ (M = Zn, Cd) layers. However, owing to the different configurations and stacking directions of the [MB₅O₁₀]1_∞ (M = Zn, Cd) layers, Rb₃ZnB₅O₁₀ and Rb₃CdB₅O₁₀ are not isostructural. The IR spectra further confirm the presence of both BO₃ and BO₄ groups and UV-Vis-NIR diffuse reflectance spectra show their band gaps are 2.66 and 2.34 eV for Rb₃ZnB₅O₁₀ and Rb₃CdB₅O₁₀, respectively. [ABSTRACT FROM AUTHOR]