Antimony phosphate, (also calledantimony orthophosphate, orantimonous phosphate) is a chemical compound ofantimony andphosphate with formulaSbPO4. Antimony is in the form Sb(III) with +3 oxidation state. Antimony atoms have alone pair of electrons.
SbPO4 occurs as a layered compound. Two-dimensional layers are weakly held together by electrostatic forces.SbPO4 is one of the most compressible materials, and under pressure compresses more perpendicular to the layers. At standard conditionsSbPO4 crystallises in a monoclinic form[2] with space groupP21/m. Antimony phosphate has been investigated for use in lithium ion and sodium ion batteries.[3][4]
Antimony atoms are attached to four oxygen atoms. These atoms are arranged as a squarish pyramid with antimony at the apex. Antimony atoms form the top and bottom of the layers. Four oxygen atoms are arranged tetrahedrally around phosphorus.[2] Antimony to oxygen bond lengths are 1.98 2.04 2.18 and 2.93 Å. the O-Sb-O angles are 87.9 164.8 84.1 and 85.0°.[2] The structure ofSbPO4 differs from two forms of BiPO4, where bismuth associates with five or eight phosphate groups.[2]
InSbPO4 the31P chemical shift is −18 ppm. The binding energy of the 2p electrons of phosphorus atom as determined by XPS is 133.9 eV.[5]
When the pressure exceeds 3 GPa, bonds form between the layers, but it retains the monoclinic system. But when the pressure is between 9 and 20 GPa, it transitions to a triclinic form with space groupP1.[6] 10.1021/acs.inorgchem.9b02268
The infrared spectrum shows absorption bands at 1145, 1052, and 973, 664, 590, 500, 475, and 372 cm−1. These are due to vibrations in P-O and Sb-O bonds and also bending in O-P-O bonds.[7]
Antimony(V) phosphateSbOPO4 has monoclinic crystals. It has space groupC2c. The unit cell has dimensions a = 6.791 Å, b = 8.033 Å, c = 7.046 Å, and β = 115.90°, with number of formula per unit cell of Z = 4. It is formed by heatingSb2O5·xH2O and(NH4)H2PO4. At 1218 K it loses oxygen to become antimony(III) phosphate.[8]
Howeverintercalation is also claimed with amines.[9] Intercalation of amines expands the a axis of the crystals, but leaves c, and c dimensions unaltered. The β angle is reduced. This is due to a bilayer of molecules inserting between each layer in the original crystal.[9]
There are also double salts where phosphate groups are joined to antimony.
^Melnikov, P.; Secco, M. A. C.; Guimarães, W. R.; dos Santos, H. W. L. (May 2008). "Thermochemistry of vitreous antimony orthophosphate".Journal of Thermal Analysis and Calorimetry.92 (2):579–582.doi:10.1007/s10973-007-8379-y.
^abcdKinberger, Bengt; Danielsen, Jacob; Haaland, Arne; Jerslev, Bodil; Schäffer, Claus Erik; Sunde, Erling; Sørensen, Nils Andreas (1970). "The Crystal Structure of SbPO4".Acta Chemica Scandinavica.24:320–328.doi:10.3891/acta.chem.scand.24-0320.
^Diwakar, K.; Rajkumar, P.; Subadevi, R.; Arjunan, P.; Sivakumar, M. (July 2021). "Electrospun assisted antimony phosphate (SbPO4) anode for elevated performance in sodium and lithium ion charge storage application".Journal of Alloys and Compounds.870: 159317.doi:10.1016/j.jallcom.2021.159317.
^Zhou, Xiaozhong; Deng, Hongling; Wang, Aixia; Song, Jinxu; Lei, Ziqiang; Xu, Yuxi (19 June 2023). "Antimony Oxides-Based Anode Materials for Alkali Metal-Ion Storage".Chemistry – A European Journal.29 (34): e202300506.doi:10.1002/chem.202300506.PMID36988079.
^Sudarsan, V; Muthe, K.P; Vyas, J.C; Kulshreshtha, S.K (April 2002). "PO43− tetrahedra in SbPO4 and SbOPO4: a 31P NMR and XPS study".Journal of Alloys and Compounds.336 (1–2):119–123.doi:10.1016/S0925-8388(01)01888-6.
^Pereira, André Luis de Jesus; Santamaría-Pérez, David; Vilaplana, Rosário; Errandonea, Daniel; Popescu, Catalin; da Silva, Estelina Lora; Sans, Juan Angel; Rodríguez-Carvajal, Juan; Muñoz, Alfonso; Rodríguez-Hernández, Plácida; Mujica, Andres; Radescu, Silvana Elena; Beltrán, Armando; Otero-de-la-Roza, Alberto; Nalin, Marcelo; Mollar, Miguel; Manjón, Francisco Javier (6 January 2020). "Experimental and Theoretical Study of SbPO4 under Compression".Inorganic Chemistry.59 (1):287–307.arXiv:2102.10111.doi:10.1021/acs.inorgchem.9b02268.hdl:10234/186679.
^abcAlonzo, G.; Bertazzi, N.; Galli, P.; Massucci, M.A.; Patrono, P.; Saiano, F. (August 1998). "On the synthesis and characterization of layered antimony(III) phosphate and its interaction with moist ammonia and amines".Materials Research Bulletin.33 (8):1221–1231.doi:10.1016/S0025-5408(98)00094-4.
^Piffard, Y.; Oyetola, S.; Verbaere, A.; Tournoux, M. (June 1986). "Synthesis, thermal stability, and crystal structure of antimony(V) phosphate SbOPO4".Journal of Solid State Chemistry.63 (1):81–85.doi:10.1016/0022-4596(86)90155-6.
