[1] Univ Southampton, Sch Chem, Southampton SO17 1BJ, Hants, England
[2] Diamond Light Source, Didcot OX11 0QX, Oxon, England
[3] CCLRC Daresbury Lab, Warrington WA4 4AD, Cheshire, England
[4] European Synchrotron Radiat Facil, F-38042 Grenoble, France