Recent thereotical determinations on the Wittig reaction point to low energy (terahertz) vibrations in the ~15-50 meV region being responsible for selectivity of this industrial proceess; recently confirmed by preliminary INS spectra taken on TOSCA. Although respectable statistics were generated for the Ph3P: and Ph3P=O, both neat and in toluene-d8 solution, results were quite poor for the ph-phospholanes, due to relatively small volume of sample available (~1.0g, however, highly dense) as well as our inepxerience preparing these samples. Current focus is therefore to complete INS determinations - armed with the experience & familiarity gained in the initial experiments. Specifically, to characterise the differences in structure and dynamics between the traditional Ph3P Wittig reagent and our novel ph-phospholane (C5-PhP) compound.