Synthesis, Structure And Characterization Of A New Silicophosphate, K2sip4o13, With A Six-Fold Coordinated Si

A potassium silicophosphate, K2SiP4O13, has been synthesized in molten polyphosphoric acid. It crystalizes in the triclinic space group P (1) over bar (No. 2) with a = 4.8327(10), b = 7.7403(15), c = 14.485(3) angstrom, alpha = 82.29(3), beta = 83.31(3), 7= 81.95, V = 529.02(19) angstrom(3), Z = 2. The crystallographic structure features 2D layers of [SiP4013L, in the ab plane with counter cations I(residing among the layers, and the anionic framework of [SiP4013100 is composed of six-fold coordinated Si atoms and tetraphosphate anions by sharing vertex 0 atoms. The title compound was characterized by powder X-ray diffraction, IR and Raman spectroscopies, UV-vis diffuse reflectance spectroscopy, thermogravimetry and differential scanning calorimetry.