title: Dynamic interaction of theory and experiment: total determination of the gas-phase molecular structure of tri-tert-butylphosphine oxide (OPBut3).
abstract: A new method to aid the determination of structures of sterically crowded molecules in the gas phase by dynamically linking the gas-phase electron diffraction (GED) refinement process with computational methods has been developed. The procedure involves refining the heavy-atom skeleton of the molecule using the GED data while continually updating the light-atom positions during the refinement using computational methods, in this case molecular mechanics. This removes errors associated with the assumption of local symmetry for the light-atom groups, which can affect the final values of the heavy-atom parameters. The refinement of the molecular structure of tri-tert-butyl phosphine oxide has been used to illustrate this new technique, which we call the DYNAMITE (DYNAMic Interaction of Theory and Experiment) method. Re-examination of the structure using this method has resulted in a shorter P-O distance than was found in a less sophisticated anaylsis, and is consistent with the molecule being regarded as O=PBut3, rather than O(-)-P+But3.
authors.affiliation: School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, UKEH9 3JJ
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Hinchley
authors.forename: Mairi F
authors.initials: MF
authors.lastname: Haddow
authors.forename: David W H
authors.initials: DW
authors.lastname: Rankin