Zinc phthalocyanine π-conjugately linked with electron-withdrawing benzothiadiazole towards broad absorption

New zinc phthalocyanine, peripherally functionalized with eight electron-withdrawing benzothiadiazole moieties through alkynic bond linkage, has been designed and synthesized. It was found that DBU acts as a ligand to coordinate with the central zinc ion at the axial direction. By this strategy, not only broad absorption covering the range of 300 ~ 900 nm, but also good solubility in common organic solvents and amorphous stability were achieved, making it an attractive candidate for potential application in solution processed small molecule-based organic photovoltaic devices.