We have created very short intermolecular hydrogen bonds in benzoic acid "dimers" by co-crystallisation of these into molecular complexes with the proton sponge 1,8-bis(dimethylamino)naphthalene (DMAN). In the presence of DMAN the benzoic acid moelciles (one of which is deprotonated) are held together by one short rather than two moderate hydrogen bonds. These hydrogen bonds are the shortest known linkages between benzoic acid derivative molecules in the solid state. In view of their intrinsic interest and also because of the known susceptibility of such hydrogen bonds to have their characteristics tuned as a function of external variable, we recently carried out a variable temperature SXD study. We now wish to investigate this materials under modest high pressure conditions up to 5kbar, to investigate the structural changes that may occur in this regime.