Investigation of New Alkali Bismuth Oxosulfates and Oxophosphates with Original Topologies of Oxo-Centered Units

摘要

Two new alkali bismuth oxosulfates, [Bi_(12)O_(15)]- Li_2(SO_4)_4 (I) and [Bi_7K_2O_8]K(SO_4)_4 (II), have been synthesized by heating a mixture of Bi_2O_3, CuSO_45H_2O, and A_2CO_3(A = Li, K), and characterized by single crystal XRD, transmission electron microscopy, and multiphoton SHG and IR spectroscopy. In the above formula the [Bi_xO_y] subunits denote the 3D-porous (I) or 1D-columnar (II) polycationic host-lattice formed of edge-sharing OBi_4 or O(Bi,K)_4 oxocenterd tetrahedra. The SO_4 ~(2-) groups and alkali ions are arranged into channels in the interstices leading to original opened crystal structures for these two first reported alkali oxo-bismuth sulfates. The strong adaptability of the oxocentered framework is demonstrated by the possibility of preparing single crystals of[Bi_(8.73)K_(0.27)O_8]K_(1.54)(PO_4)_4 (III) whose crystal structure is similar to those of II with disorder between OBi_4 and O(Bi_3,K) tetrahedra and different channel occupancy due to the aliovalent replacement of SO_4 ~(2-) for PO_4 ~(3-).