To determine the energies of the HOMO and LUMO levels, we performed cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements (Figure ). The corresponding HOMO energy levels extracted from the peak value of first oxidation wave (E ox = 0.95 V, 0.99 V, and 1.0 V vs SCE) of the DPVs were found to stabilize only slightly along the series, being -5.75 eV, -5.79 eV, -5.80 eV for 4TABN1, 5TABN2 and 6TABN3, respectively. The LUMO levels were determined from the peak value of first reduction wave of the DPVs (E red = -2.25 V, -2.17 V, and -2.14 V vs SCE) and correspond to -2.55 eV, -2.63 eV, and -2.66 eV, respectively, and are also stabilized slightly along the series. The corresponding energy gaps were likewise found to decrease slightly at 3.20 eV, 3.16 eV and 3.14 eV, respectively, for 4TABN1, 5TABN2 and 6TABN3 as a function of an increasing number of repeat units. The trends in both progressively stabilizing HOMO and LUMO align well with the DFT calculated trends (vide infra). We started our photophysical study with low-concentration (ca 10 -5 M) toluene solution measurements to investigate the photophysical properties of the monomolecular species. Figure presents the room temperature absorption and photoluminescence (PL) spectra of 4TABN1, 5TABN2 and 6TABN3. All molecules show the same absorption profile but differ in the band intensity. Taking into account the nature of the donor and acceptor units, we assign the band at 4.23 eV (ca 293 nm) to the p-p* absorption of the tolylamine donor unit, while absorption of the benzonitrile acceptor occurs at higher energy. The intensity of the band at 4.23 eV (293 nm) increases with increasing number of donors. There is also a broad, low intensity and structureless absorption band at 3.15 eV (394 nm) for 4TABN1 that is associated with intramolecular charge transfer (CT) states (vide infra). The intensity of this band also increases with increasing number of donor-acceptor units (c.f. Table ). A small blue-shift of the maximum of the CT band (0.07 eV for 5TABN2 and 0.09 eV for 6TABN3) implies on average a population of more twisted conformers