Cd3(PO4)(TePO6): A Novel Cadmium Tellurite-Phosphate featuring a {[TePO6]3−}∞ Chain

Graphical A novel transition metal tellurite phosphate Cd 3 (PO 4 )(TePO 6 ) features a new type of {[TePO 6 ] 3− } ∞ chain was obtained by solid-state reactions, and its electronic structure and optical properties are studied systematically. New inorganic crystals containing multiple anions have received extensive attensions recently in view of their abilities to be potential multifunctional materials. Among them, tellurite-phosphates with simple chemical components are relatively rarely studied. Here, one novel tellurite phosphate Cd 3 (PO 4 )(TePO 6 ) was obtained through conventional soild-state reaction, and it is the first tellurite-phosphate only possessing d 10 transition metal. It crystallizes in the monoclinic space group P 2 1 / c , and its structure features an interesting {[TePO 6 ] 3− } ∞ chain constructed by corner-sharing connected PO 4 and TeO 4 tetrahedra. Meanwhile, we obtained a new phase of Cd 3 (PO 4 ) 2 and Cd 1.725 Mg 1.275 (PO 4 ) 2 in the exploration of tellurite-phosphates, and they also crystalize in the centric space group P 2 1 / c . Crystal structures, theoretical calculations on their electronic structure and birefringence have been studied, together with the IR and UV-vis-NIR diffuse reflectance spectra.