Bi-3(PO4)O-3, the Simplest Bismuth(III) Oxophosphate: Synthesis, IR Spectroscopy, Crystal Structure, and Structural Complexity

The bismuth(III) oxophosphate Bi-3(PO4)O-3 was obtained by hydrothermal synthesis. The unit cell has a = 5.6840(6) angstrom, b = 7.0334(7) angstrom, c = 9.1578(9) angstrom, alpha = 78.958(2)degrees, beta = 77.858(2)degrees, gamma = 68.992(2)degrees, V = 331.41(6) angstrom(3) , space group P (1) over bar, and Z = 2. The crystal chemical formula that reflects the presence of oxo-centered-tetrahedra and triangles is (2D)[(OO2Bi3)-O-III-Bi-IV] (PO4). The crystal structure contains [O3Bi3](3)+(infinity infinity)-heteropolyhedral corrugated layers parallel to (001), which alternate along [001] with isolated (PO4) tetrahedra. The structural complexity parameters are v = 22 atoms, I-G = 3.459 bits/atoms, and I-G,I-total = 76.107 bits/unit cell, and thus Bi-3(PO4)O-3 is the simplest pure bismuth(III) oxophosphate.