Hydrothermal synthesis, crystal structures, and optical properties of H[Bi3O(Te3O9)](NO3)2 and [Bi2(TeO3)2](SO4)

Two new mixed bismuth (III) tellurite nitrate/sulfate, H[Bi 3 O(Te 3 O 9 )](NO 3 ) 2 and [Bi 2 (TeO 3 ) 2 ](SO 4 ) were synthesized under hydrothermal conditions. H[Bi 3 O(Te 3 O 9 )](NO 3 ) 2 crystallizes in the hexagonal space group P 6 ¯ 2  m (No. 189) with lattice parameters a  = 9.8465(4), b  = 9.8465(4), c  = 4.1917(4) Å, V = 351.95(4) Å 3 , Z = 1, while [Bi 2 (TeO 3 ) 2 ](SO 4 ) crystallizes in the monoclinic space group C 2/ c (No. 15) with lattice parameters a  = 15.7657(13), b  = 7.4285(5), c  = 8.0959(6) Å, β  = 112.693(2) ° , V = 874.75(11) Å 3 , Z = 4. The structure of H[Bi 3 O(Te 3 O 9 )](NO 3 ) 2 features one-dimensional cationic 1 ∞ [Bi 3 O(Te 3 O 9 )] + chains along c axis, which are composed of [BiO 7 ] and [TeO 4 ] polyhedra by sharing corners and edges, whereas [Bi 2 (TeO 3 ) 2 ](SO 4 ) possesses a new three-dimensional framework consisting of two-dimensional zigzag layers of 2 ∞ [Bi 2 (TeO 3 ) 2 ] 2+ that are linked by SO 4 2- anions. Title compounds were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, Raman spectra, infrared spectra and solid state UV-vis-NIR diffuse reflectance spectroscopy .