No abstract

Synthesis of a series of new organic photosensitizers, designated as BZ1-BZ4, was achieved by incorporating benzofuran core as π-spacer, triphenylamine (TPA) and 4-methoxy triphenylamine (4-MeO-TPA) as donors and cyanoacrylic acid (CAA) and rhodanine-3-acetic acid (RAA) as acceptor/anchoring groups. Structurally, dyes BZ1 and BZ2 carry TPA and 4-MeO-TPA as donors, respectively, whereas CAA constitutes as a common acceptor. On the other hand, BZ3 and BZ4 incorporate TPA and 4-MeO-TPA as donors, respectively, and RAA serves as a common acceptor. Key steps to access BZ1-BZ4 involved Wittig olefination, reduction of cyano groups to aldehyde, and finally Knoevenagel condensation. In UV-visible spectra, dyes BZ1-BZ4 exhibited intramolecular charge transfer (ICT)