The design and synthesis of an asymmetrical zinc phthalocyanine sensitizer modified with a catechol anchoring group is reported. The performance of this sensitizer was evaluated in a dye-sensitized solar cell. A strong interaction between the catechol dye and TiO2 (with the formation of a five-membered charge-transfer complex) was evidenced by a strong shift in the Q-band of the ZnPc-Cat from 680 nm in solution to 750 nm on TiO2, along with an ...