Interlayer molecular exchange in an anticlinically ordered chiral liquid crystal

The interlayer molecular exchange has been determined in the antiferroelect ric smectic-C-A* phase of alpha d(2) deuterated 4-(1-methylheptyloxycarbony l)phenyl4'-octyloxybiphenyl-4-carboxylate via quadrupolar deuteron NMR self -diffusion in the spatially varying electric field gradient produced by the anticlinic smectic layer structure. The interlayer self-diffusion coeffici ent is here by two orders of magnitude smaller than in synclinically ordere d smectic phases. The results support the entropic suppression model of the origin of anticlinic smectic ordering. The applied technique could possibl y allow for a new insight into the local structure of the intermediate "clo ck" phases.