Skeletons with syn-periplanar bis-azo-chromophoric units (8,18,19) have been synthesized (8: transannular NN/NN-distances 2.939(2.999) Å, interorbital angle ω = 154.3°, X-ray analysts). In no case azo/azo-photocycloaddition has been observed upon direct or sensitized excitation.