Molecular materials of the form electron donor-sigma-bridge-electron acceptor (D-σ-A) have been synthesized and incorporated into non-centrosymmetric Langmuir-Blodgett (LB) multilayer structures. Electrical characterization has been performed using a metal|(Z-type LB film)|metal (M|LB|M) junction construction. Current density-voltage data demonstrate striking rectification behaviour. Computational modelling of the electronic structure of the material has been carried out using a first principles, density functional approach. Possible conduction mechanisms are discussed with reference to the results of this modelling.