Carboxy-substituted D-π-A arylated chalcones: Synthesis, photophysical properties and preliminary evaluation as photosensitizers for DSSCs.

Chalcones are versatile molecules with potential use in various fields and technologies. The judicious choice of chalcones' building blocks allows the design of compounds with different properties and applications. In the present work, four highly conjugated carboxy-substituted chalcones with D-π-A architecture were synthesized aiming their evaluation as photosensitizers for dye-sensitized solar cells (DSSCs). In their architecture, electron-rich aldehydes were used as precursors of the donor units, and carboxylate or cyanoacrylate acceptor units were bonded to the acetophenone portion. The compounds presented intense UV–vis absorptions (ε in the order of 104 mol L−1 cm−1) centered between 322 and 429 nm, and blue to yellow fluorescence, with quantum yields ranging from less than 0.01 to 0.35. These chalcones were evaluated as photosensitizers for DSSCs, displaying short-circuit current density (I SC) ranging from 0.18 to 0.36 mA cm−2, open circuit voltage (V oc) from 0.52 to 0.56 V, fill factor (FF) between 54 and 67%, and power conversion efficiency from 0.05 to 0.13%. The two best performances were obtained with photosensitizers 6a and 7b which display the pairs dimethylaminophenyl/carboxylate and vanillin/cyanoacrylate as the donor and acceptor/anchoring units, respectively. [Display omitted] • Four novel carboxy-substituted D-π-A chalcones were synthesized. • Vanillin and other electron-rich aldehydes were used as precursors of the donor groups. • All chalcones presented intense UV–vis absorption and the ability to bind to TiO 2. • The chalcone having N(Me) 2 as donor and benzoate as acceptor/anchoring group presented the best performance in DSSCs. [ABSTRACT FROM AUTHOR]