Two new isotypic diphosphates, LiNa3P2O7 (1) and LiK3P2O7 (2), have been synthesized by conventional solid-state reaction. The single-crystal X-ray structural analyses have shown that they crystallize in the orthorhombic space group C2221 (No. 20) with the unit cells: a=5.4966(2) A˚, b=9.1365(4) A˚, c=12.2764(5) A˚ for compound 1 and a=6.0373(14) A˚, b=9.339(2) A˚, c=13.292(3) A˚ for compound 2. The LiM3P2O7 (M=Na, K) consist of two-dimensional [LiP2O7]3- layers, which are composed by LiO4 tetrahedral and diphosphate groups, the Na or K atoms are filled in the interlayers and balance the charge. Second harmonic generation (SHG) on powder samples have been measured using Kurtz and Perry techniques. Thermal analyses, IR spectroscopy, UV-vis-NIR diffuse reflectance spectra, and band structure calculations are performed on the reported compounds.
Chinese Acad Sci, Xinjiang Tech Inst Phys & Chem, Xinjiang Key Lab Elect Informat Mat & Devices, Urumqi 830011, Peoples R China;Chinese Acad Sci, Grad Univ, Beijing 100039, Peoples R China
Shi Yunjing,Wang Ying,Pan Shilie,et al. Synthesis, crystal structures and optical properties of two congruent-melting isotypic diphosphates: LiM3P2O7 (M = Na, K)[J]. JOURNAL OF SOLID STATE CHEMISTRY,2012,197(1):128-133.