TY - JOUR
T1 - Temperature dependence of the crystal structure of α-AgSCN by powder neutron diffraction
AU - Williams, Darrick J.
AU - Daemen, L. L.
AU - Vogel, S. C.
AU - Proffen, Th
PY - 2007/11/10
Y1 - 2007/11/10
N2 - A structural study of α-AgSCN was carried out using the neutron powder diffractometer HIPPO (high-pressure preferred orientation powder) at ten different temperatures between 25 and 275 K. The structure of α-AgSCN was refined using the Rietveld method and the symmetry elements for the material were found to be: space group No. 15, C2/c, a = 8.7210 (8) Å, b = 7.9318 (8) Å, c = 12.3329 (5) Å, β = 138.750 (3)°, volume = 562.497 (9) Å3 and Z = 8. The Ag+ cation has tetrahedral coordination and is surrounded by three -SCN thiocyanate ligands and one isothiocyanate -NCS ligand down to 25 K, with no structural changes. The bond lengths at 275 K are Ag-S1 = 2.749 (10), Ag-S2 = 2.995 (11), Ag-S3 = 2.411 (11), Ag-N = 2.150 (5), S-C = 1.783 (11) and C-N = 1.1447 (35) Å. The bond lengths at 25 K are Ag-S1 = 2.782 (5), Ag-S2 = 2.941 (5), Ag-S3 = 2.431 (5), Ag-N = 2.1526 (26), S-C = 1.749 (5) and C-N = 1.140 (2) Å.
AB - A structural study of α-AgSCN was carried out using the neutron powder diffractometer HIPPO (high-pressure preferred orientation powder) at ten different temperatures between 25 and 275 K. The structure of α-AgSCN was refined using the Rietveld method and the symmetry elements for the material were found to be: space group No. 15, C2/c, a = 8.7210 (8) Å, b = 7.9318 (8) Å, c = 12.3329 (5) Å, β = 138.750 (3)°, volume = 562.497 (9) Å3 and Z = 8. The Ag+ cation has tetrahedral coordination and is surrounded by three -SCN thiocyanate ligands and one isothiocyanate -NCS ligand down to 25 K, with no structural changes. The bond lengths at 275 K are Ag-S1 = 2.749 (10), Ag-S2 = 2.995 (11), Ag-S3 = 2.411 (11), Ag-N = 2.150 (5), S-C = 1.783 (11) and C-N = 1.1447 (35) Å. The bond lengths at 25 K are Ag-S1 = 2.782 (5), Ag-S2 = 2.941 (5), Ag-S3 = 2.431 (5), Ag-N = 2.1526 (26), S-C = 1.749 (5) and C-N = 1.140 (2) Å.
KW - Disorder
KW - Order
KW - Pseudohalides
KW - Silver thiocyanate
KW - Thermal expansion
UR - http://www.scopus.com/inward/record.url?scp=36048992794&partnerID=8YFLogxK
U2 - 10.1107/S0021889807048236
DO - 10.1107/S0021889807048236
M3 - Article
AN - SCOPUS:36048992794
SN - 0021-8898
VL - 40
SP - 1039
EP - 1043
JO - Journal of Applied Crystallography
JF - Journal of Applied Crystallography
IS - 6
ER -