Two series of linearly conjugated hybrid materials, consisting of (E)-1,2-diethynylethene (DEE; hex-3-ene-1,5-diyne) and ZnII porphyrin components, were prepared by Pd0-catalyzed cross-coupling reactions. In one series, one or two DEE substituents were introduced into the meso-positions of the ZnII porphyrins, leading from 5⋅Zn, to 9 and 1 (Scheme 1). The second series contains the linearly π-conjugated molecular rods 1 – 3 that span a length range from 23 A (1) to 53 A (3) (Fig. 1). The larger rods 2 and 3 consist of two or three porphyrin moieties, respectively, that are bridged at the meso-positions by trans-enediynediyl (hex-3-ene-1,5-diyne-1,6-diyl) linkers (Scheme 2). The UV/VIS spectra in the series 5⋅Zn, 9, and 1 (Fig. 2) showed a strong bathochromic shift of both Soret and Q bands of the ZnII porphyrin as a result of the addition of DEE substituents. Upon changing from 1 to 2 (Fig. 3), the Q band was further bathochromically shifted, whereas the Soret band remained nearly at the same position but became broadened and displayed a shoulder on the lower-wavelength edge as a result of excitonic coupling. The close resemblance between the UV/VIS spectra of 2 and 3 suggests that saturation of the optical properties in the oligomeric series already occurs at the stage of dimeric 2. Stationary voltammetric investigations showed that the DEE substituents act as strong electron acceptors which induce large anodic shifts in the first reduction potential upon changing from 5⋅Zn to 9 (ΔE=190 mV) and to 1 (ΔE=340 mV). Increasing the number of porphyrin moieties upon changing from 1 to 2 had no effect on the first reduction potential yet the first oxidation potential was substantially lowered (ΔE=110 mV). Large differences in the potentials for one-electron oxidation of the two porphyrin moieties in 2 (ΔE=200 mV) confirmed the existence of substantial electronic communication between the two macrocycles across the trans-enediynediyl bridge.