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In the last years, conjugated oligothiophene macrocycles have attracted increasing scientific interest due to some peculiar properties related to their cyclic structure [1-3]. T. Benincori et al. synthesized the 2,2′-bis(2,2′-bithiophene-5-yl)-3,3′-bithianaphthene nicknamed BT2T4 (Figure 1) that represents the first member of a new class of chiral oligothiophenes in which chirality results from a tailored torsion produced in the polyconjugated backbone and not from the presence of stereogenic centres, external to it. Interestingly, the FeCl3 oxidation of the enantiopure BT2T4 produce a mixture of chiral macrocycles, like dimers and trimers. [4] Recently, also thanks to DFT and TD-DFT calculations, we have studied the new monomer BT2E4 in order to investigate the role of the insertion of 3,4-ethylenedioxythiophene (EDOT) units on the electronic and molecular properties of neutral and charged monomer and oligomer species. Furthermore, the electroactive films were evaluated by cyclic voltammetry (CV), UV/vis spectroelectrochemistry and CV coupled with in-situ conductance measurements. [5] Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

New stilbenoid and thiophenic compounds terminally functionalized with donor-donor, acceptor-acceptor and donoracceptor moieties and substituting a central [2,2]paracyclophane unit have been prepared and their properties interpreted in terms of through-bond and through space conjugations. A description of the excited state properties based on photophysical data and with focus on the participation of the central [2,2]paracyclophane, or “phane” state, in competition with through-bond conjugation in the arms has been conducted. To this end, one-photon absorption and emission spectroscopy, as a function of temperature, of solvent polarity in solution and of pressure in solid state have been carried out. Furthermore, the analysis of charge delocalization in the face-toface [2,2]paracyclophane part in the neutral state and in the oxidized species (dications and trications) has been assessed allowing to elucidate the vibrational Raman fingerprint of charge delocalization in these systems. Thus, a complementary approach to “intermolecular” excitation and charge delocalization has been presented in [2,2]paracyclophane model systems by means of the pertinent spectroscopic techniques.

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