THE DISORDERED STRUCTURE OF WO2CL2 - A POWDER DIFFRACTION STUDY

The crystal structure of the intercalation host WO2Cl2, Fw = 286.85, has been refined using powder neutron diffraction. Refinement was carried out in the orthorhombic space group, Immm, with a = 3.8414(1), b = 3.8851(1), c = 13.8720(4) Å, V = 207.03 Å3, Z = 2. The final R factors are Rwp = 5.22%, Rex = 4.74%, X2 = 1.21 for 26 basic variables with 7000 observations corresponding to 292 reflections. The structure consists of layers of tungsten oxide sandwiched between chloride ions to form trilayer blocks of general formula [Cl-WO2-Cl]n. These blocks stack in the c -direction to generate the three-dimensional structure. Only weak van der Waals forces hold the blocks together and as a result the compound is an excellent host for intercalation. The structure shows a distorted W environment accompanied by significant disorder in the layer planes. © 1993 Academic Press, Inc.