The synthesis of the title oligomers was performed by means of an iterative sequence of 1,3-dipolar cycloaddition reactions of appropriate azides, starting from commercial 4-bromo-1-butyne as a key intermediate.

A general procedure for the synthesis of the title compounds has been devised starting from the available 2-halophenylethyl azides, by means of click reactions with trimethylsilylacetylene or 1-trimethylsilyl-1,3-butadiyne followed by a transition metal-catalyzed functionalization of C–H bond. A further extension of this procedure led us to devise the synthesis of more complex 4,4¢-bitriazole-fused dihydroisoquinolines

A convenient synthesis of 4-(1,2,3-triazolylalkyl)-1,2,3-triazole fused dihydroisoquinolines and dihydroisoindoles is reported, starting from easily available (2-iodoaryl)alkyl azides and terminal alkynols. The procedure is based upon transition-metal catalyzed coupling reactions followed by iterative cycloaddition reactions.

A convenient synthesis of 1,2,3-triazole-fused isoindolines and dihydroisoquinolines in good to excellent yield is reported, starting from easily available terminal alkynes and (2-haloaryl)alkylazides. The method is based upon a cycloaddition reaction, via click chemistry, followed by a transition metal-catalyzed functionalization of a CeH bond.

Ternary blends comprising an ‘energy-cascade former’ in addition to the donor and the acceptor materials increasingly attract attention in the organic solar cell area as they seem to provide a tool to positively manipulate the open-circuit voltage of bulk-heterojunction devices. By comparing two additives that have similar HOMO/LUMO levels and that can be expected to lead to an energy cascade in ternaries with the prototypical P3HT:PC60BM system, we demonstrate here that the compatibility of the additive with, in this specific case, the fullerene, that can be tailored by peripheral chemical functionalization, plays a critical role in energy cascade formation. A compromise needs to be found between good mixing (favoring energy cascade formation) and phase separation (supporting charge extraction) that affect the open-circuit voltage in an as important fashion as their electronic features, providing critical insights for future materials design activities.

The synthesis of two new dye families of croconic acid derivatives, semicroconaine and non-symmetric croconaine dyes, is reported for the first time. These compounds show strong absorption in the UV-visible and NIR, respectively. Semicrocon-aine dyes were obtained by a scalable and efficient condensation of croconic acid with aromatic heterocyclic methylene-active compounds. The subsequent reaction of the semicroconaine dyes with aromatic heterocyclic compounds affords non-symmetric croconaines. The structure and electronic properties of the synthesized compounds have been investigated by preliminary theoretical calculations at DFT level of approximation.

Alkyl thiols are processing additives for bulk heterojunction (BHJ) solar cells useful for substituting post-production treatment with low energy consuming processes (1). They modify the solubility of donor:acceptor couple in the host solvent, impacting solid state nanoscale phase separation. After deposition, thiol solvent presumably evaporates from the blend. Conjugated structures with pending alkylthiol groups could be interesting for ternary blend (2) polymer solar cells. Such materials could not only optimize the active layer morphology, but contribute by means of their conjugated structure to light harvesting and charge generation processes operating in the solar cell. Building on our experience in the synthesis of thiolated materials (3), we recently synthesized a family of organic semiconductors with low bandgap and pending alkylthiol groups. Their study in all organic or hybrid nanostructures represents an unexplored dimension in new generation photovoltaics. We present their synthesis and demonstrate the photovoltaic response of one of these compounds employed as additive in P3HT:PCBM solar cells. (1) Solar Energy 2011, 85,1226; (2) Adv. Mater. 2013, 25, 4245; (3) J. Org. Chem. 2007,72, 10272; Eur. J. Org. Chem. 2011, 529; Curr. Org. Synth., 2012, 9, 764.