This tutorial review surveys and highlights the integration of different molecular wires-in combination with chromophores that exhibit (i) significant absorption cross section throughout the visible part of the solar spectrum and (ii) good electron donating power-into novel electron donor-acceptor conjugates. The focus is predominantly on charge transfer and charge transport features of the most promising systems.

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Controlling self-organization and morphology of chemical architectures is an essential challenge for the search of higher energy-conversion efficiencies in a variety of optoelectronic devices. Here, we report a highly ordered donor/acceptor functional material, which has been obtained using the principle of ionic self-assembly. Initially, an electron donor π-extended tetrathiafulvalene and an electron acceptor perylene-bisimide were self-organized separately obtaining n-and p-nanofibers at the same scale. These complementary n-and p-nanofibers are endowed with ionic groups with opposite charges on their surfaces. The synergic interactions establish periodic alignments between both nanofibers resulting in a material with segregated and alternately stacked donor/acceptor nanodomains. Photoconductivity measurements show values for these n/p-co-assembled materials up to 0.8 cm 2 V -1 s -1 , confirming the effectiveness in the design of these heterojunction structures. This easy methodology offers great possibilities to achieve highly ordered n/p-materials for potential applications in different areas such as optoelectonics and photovoltaic.The control on the organization and morphology of organic materials at different scales is an essential challenge in current science. 1 In particular, organic materials employed for obtaining efficient photovoltaic devices require a controlled segregation of electron donor/acceptor domains in the active layers because transport of the photo-generated charge carriers occurs through these domains to the electrodes. This control over the organization of nanostructured domains at the same length scale generally results in an increase in conductivity or photoconductivity values. 2 One of the approaches to prepare optoelectronic materials for photon-energy conversion is the use of covalent donor-acceptor (D-A) dyads. In this context, a great variety of D-A dyads have been reported with an elaborated synthetic strategy. 3-5 These D-A dyads provide nanoscale D-A heterojunctions with different morphologies such as fibrous, 3 tubular 4 or liquid crystals, to name a few. 5 On the other hand, supramolecular chemistry is gaining attention, when compared to covalent methodologies, due to its higher versatility and easier ensembles preparation. From small molecules and through weak and non-covalent intermolecular interactions such as hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, π-π stacking and electrostatic interactions, it is possible to reach highly ordered structures at the nano and mesoscales. 6

Aims. We present the novel InterStellar Astrochemistry Chamber (ISAC), designed for studying solids (ice mantles, organics, and silicates) in interstellar and circumstellar environments: characterizing their physico-chemical properties and monitoring their evolution as caused by (i) vacuum-UV irradiation; (ii) cosmic ray irradiation; and (iii) thermal processing. Experimental study of thermal and photodesorption of the CO ice reported here simulates the freeze-out and desorption of CO on grains, providing new information on these processes. Methods. ISAC is an UHV set-up, with base pressure down to P = 2.5 × 10 −11 mbar, where an ice layer is deposited at 7 K and can be UV-irradiated. The evolution of the solid sample was monitored by in situ transmittance FTIR spectroscopy, while the volatile species were monitored by QMS. Results. The UHV conditions of ISAC allow experiments under extremely clean conditions. Transmittance FTIR spectroscopy coupled to QMS proved to be ideal for in situ monitoring of ice processes that include radiation and thermal annealing. Thermal desorption of CO starting at 15 K, induced by the release of H 2 from the CO ice, was observed. We measured the photodesorption yield of CO ice per incident photon at 7, 8, and 15 K, respectively yielding 6.4 ± 0.5 × 10 −2 , 5.4 ± 0.5 × 10 −2 , and 3.5 ± 0.5 × 10 −2 CO molecules photon (7.3-10.5 eV) −1 . Our value of the photodesorption yield of CO ice at 15 K is about one order of magnitude higher than the previous estimate. We confirmed that the photodesorption yield is constant during irradiation and independent of the ice thickness. Only below ∼5 monolayers ice thickness the photodesorption rate decreases, which suggests that only the UV photons absorbed in the top 5 monolayers led to photodesorption. The measured CO photodesorption quantum yield at 7 K per absorbed photon in the top 5 monolayers is 3.4 molecules photon −1 . Conclusions. Experimental values were used as input for a simple model of a quiescent cloud interior. Photodesorption seems to explain the observations of CO in the gas phase for densities below 3-7 ×10 4 cm −3 . For the same density of a cloud, 3 × 10 4 cm −3 , thermal desorption of CO is not triggered until T = 14.5 K. This has important implications for CO ice mantle build up in dark clouds.

Weak wire-like behavior-with a damping factor (beta) of 0.2 +/- 0.05 A(-1)--has been found in a series of C60-wire-exTTF systems (i.e., p-phenyleneethynylene): these results contrast with previous observations involving p-phenylenevinylene systems.