Our recent works have solved a 50 yr old problem (in part) with computational steering successfully guiding synthetic work towards a wittig process catalytic in phosphine. The work was deemed a ¿hot article¿ in Angewandte Chemie, the impact of which was immediately highlighted in Nature Chemistry and Chemical&Enginnering News. Despite the synthetic successes, the mechanisms by which these reactions proceed are still not well understood, while their selectivity (E vs. Z product) is not known at all. Recent thereotical determinations point to low energy (terahertz) vibrations in the fingerprint region being responsible for product selectivity. Of particular focus is to characterise the differences in structure & dynamics between the traditional PPh3 Wittig reagent and our novel compounds and their oxidised counterparts. We propose to characterise the fingerprint vibration region of each.