Application of singular value decomposition to time-resolved X-ray data; simulations and experiments

Abstract

The crystal structures of two small organic molecules 7oxabicyclo[2.2.1]heptane (C6H10O) and norcamphor (C7H10O) have been investigated using synchrotron X-ray powder diffraction at BM16 at the ESRF.The temperature dependence of the 7-oxabicyclo[2.2.1]heptane and norcamphor diffraction pattern reveals different solid-state phase transitions.For the 7-oxabicyclo[2.2.1]heptane phase I is between 251 K and 234 K, phase II 234 K-192 K, phase III 191 K-185 K, phase IV below 182 K.For the norcamphor we observed phases between 288 K and 165 K, 164 K-154 K, and below 146 K.The crystal structures in the low-temperature phases of the 7oxabicyclo[2.2.1]heptane have been studied at 50 K and 185 K.At 50 K the compound is found to be monoclinic, space group P21/a, with a = 24.041Å, b = 10.259Å, c = 13.637Å, β = 102.52°and Z = 24.The crystal structures in the low-temperature phases of the Norcamphor have been studied at 35 K and 185K.At 35K the compound is found to be monoclinic, space group C21/c, with a = 18.443Å, b = 12.285 Å, c = 13.685Å, β= 90.96° and Z = 16.