We wish to measure the low-field ALCs of a series of related functionalised acenes to identify which mechanism (spin orbit or hyperfine) is responsible for spin relaxation in organic materials, by deuteration and substituting heavy atoms into organic complexes. The identification of the relevant spin scattering mechanism could lead to major breakthroughs in spin dynamics in organic semiconductors, possibly generalised to all disordered materials. Most theories of spin relaxation rely on bands resulting from the periodic crystal lattice and therefore are not applicable to disordered materials. Whilst we believe that we already have sufficient data to achieve a high-profile publication, we believe that direct evidence for the underlying mechanism will significantly aid the theoretical model we are developing and increase the impact of this publication.