A pair of 4-(1-naphthylvinyl)pyridine (4-nvp) ligands has been successfully aligned in head-to-tail fashion in a one-dimensional (1D) double chain ladder polymer [Cd(adc)(4-nvp)(2)(H2O)]n (1; H(2)adc = acetylenedicarboxylic acid) that undergoes a photochemical [2 + 2] cycloaddition reaction accompanied by single-crystal to single-crystal (SCSC) structural transformation from a 1D chain to a 2D layer structure. These structural changes have a significant impact on the conductivity and Schottky nature of the compound.