skip to main content

SciTech ConnectSciTech Connect

Title: Lithium vanadyl oxalatophosphite: Influence of the water content on the crystal structures and the dehydration scheme

Two new lithium vanadyl oxalatophosphites have been synthesized by hydrothermal treatment. The respective formula are Li{sub 2}(VOHPO{sub 3}){sub 2}C{sub 2}O{sub 4} 6H{sub 2}O (1) and Li{sub 2}(VOHPO{sub 3}){sub 2}C{sub 2}O{sub 4} 4H{sub 2}O (2). The structures of the compounds have been determined by single crystal X-ray diffraction. Compound 1 crystallizes in triclinic symmetry in space group P-1, a=6.3592(2) Å, b=8.0789(3) Å, c=9.1692(3) Å, α=64.390(2), β=87.277(2)°, γ=67.624(2) and, compound 2 in monoclinic symmetry, space group P2{sub 1}/a, a=6.3555(2) Å b=12.6368(7) Å c=9.0242(4) Å β=105.167(3)°. The vanadium phosphite framework consists of infinite chains of corner-sharing vanadium octahedra and hydrogenophosphite tetrahedra. The oxalate groups ensure the connection between the chains. The lithium ions and the water molecules are located between the anionic [(VO){sub 2}(HPO{sub 3}){sub 2}C{sub 2}O{sub 4}]{sup 2−} layers. Thermal behavior of both compounds was carefully studied by combining thermogravimetric analyses and thermal dependant X-ray diffraction in order to study the thermal stability of the layered oxalatophosphites and to see the influence of the decomposition of the carbon-based anions into the final lithium vanadyl phosphate. Various intermediate phases were evidenced and for both compounds the final product was LiVOPO{sub 4}. -- Graphical abstract: Two new lithium vanadyl oxalatophosphites layered compounds, Li{sub 2}more » (VOHPO{sub 3}){sub 2}C{sub 2}O{sub 4} 6H{sub 2}O (1) and Li{sub 2} (VOHPO{sub 3}){sub 2}C{sub 2}O{sub 4} 4H{sub 2}O (2) have been hydrothermally synthesized. Lithium ions and water molecules are located between the anionic [(VO){sub 2}(HPO{sub 3}){sub 2}C{sub 2}O{sub 4}]{sup 2−} layers. Thermal behaviors were carefully studied by thermogravimetric and thermal dependant X-ray diffraction. Various intermediate phases were evidenced and for both compounds the final product was LiVOPO{sub 4}. Highlights: • The first lithium vanadium oxalatophosphite have been synthesized hydrothermally. • The structure of these compounds is related to vanadium oxalato-phosphates. • Hydrogen bonding in starting material influences the intermediate phase structures. • Thermal decomposition evidences two Li{sub 2}[(VO){sub 2}(HPO{sub 3}){sub 2}C{sub 2}O{sub 4}] anhydrous polymorphs.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [2] ;  [1] ;  [2] ; ;  [4] ;  [5] ;  [1] ;  [2]
  1. Sciences Chimiques de Rennes, UMR 6226, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France)
  2. (France)
  3. Sciences Chimiques de Rennes, UMR 6226, Université de Rennes 1, CNRS, Campus de Beaulieu, 35042 Rennes Cedex (France)
  4. Facultad de Quimia y Biologia, Universitad de Santiago de Chile, USACH, Casilla, 40 Correo 33, Santiago (Chile)
  5. (Chile)
Publication Date:
OSTI Identifier:
22275868
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 211; Journal Issue: Complete; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DECOMPOSITION; DEHYDRATION; HYDROTHERMAL SYNTHESIS; LAYERS; LITHIUM; LITHIUM IONS; MONOCLINIC LATTICES; MONOCRYSTALS; NUCLEAR MAGNETIC RESONANCE; PHOSPHATES; SOLIDS; SPACE GROUPS; STABILITY; THERMAL GRAVIMETRIC ANALYSIS; VANADIUM; X-RAY DIFFRACTION