MS36-P31 A Systematic Study of Radiation Damage in Transition Metal Chloride Complexes with 1,5-cyclooctadiene Ligands using Diffraction and Spectroscopy.Transition metal chloride complexes with 1,5-cyclooctadiene ligands have a variety of applications as catalysts or precatalysts in e.g. hydrogenation and hydrogen-transfer reactions.(1) However, their interactions with X-rays has, to date, been assumed to be non-destructive with no reports in the literature of behaviours indicating radiation damage such as intensity loss in diffraction peaks or peak broadening. Interaction of X-rays with the crystal lattice is an effect that causes well-known problems in biological systems,(2) but this effect is only formally starting to be recognised in chemical crystallography. A survey of the effects of radiation damage to small molecule single crystals(3) demonstrated a relationship between the damage and the intensity of the source. The improving intensity of sources both at central facilities and for in-house instruments is increasing awareness of radiation damage, with a particular lack of understanding for small molecule crystallographers and spectroscopists currently complicating data collection. A series of compounds have been studied where M = Ir, Rh and Cu to, quite literally, shed light on the chemical changes resulting from X-ray exposure via structural and electronic insights. The combination of powder X-ray diffraction, single crystal X-ray diffraction, computational studies and X-ray photoemission spectroscopy reveal the impact of X-ray radiation on these materials in great detail and also provide insight into the importance of identifying appropriate data collection techniques for experiments.
(1) Crabtree, R. H., Morehouse, S. M. & Quirk, J. M. (2007), Inorganic Syntheses, J. M. Shreeve (Ed.). doi:10.1002/9780470132555.ch50
(2) Blake, C.C.F & D. C. Philips, (1962), Symposium of the International Atomic Energy Agency, Vienna, Austria, p. 183.
(3) Abrahams, S.C.,(1973) Acta Crystallogr., Sect. A, 29, 111.Keywords: X-rays, Catalysts, Synchrotron