Two new phosphates, KCd2P3O10 and K8Cd21Pb7(P2O7)16, have been obtained using high-temperature molten method for the first time. They show three-dimensional (3D) framework structures composed of [Cd2P3O18]∞ layers for KCd2P3O10 and [Cd36P48O237]∞ corrugated layers for K8Cd21Pb7(P2O7)16. To the best of our knowledge, K8Cd21Pb7(P2O7)16 is the first Cd-based phosphate that is constructed by tremendous [Cd18P24O121]∞ anionic duplicate units, which contain intriguing multimember-rings (6-MR, 8-MR, 16-MR). In addition, K8Cd21Pb7(P2O7)16 contains coexistent Cd2O10 single rings and Cd3O12 twin rings, which have not been found in other Cd-based phosphates. The comparison of structures was carried out among all the relevant anhydrous Cd-based phosphates. Combining with theoretical analysis, the relationship between electronic structures and optical properties is further elaborated.
