Synthesis and photophysical studies of asymmetric zinc phthalocyanine-magnetic nanoparticle conjugates

This work reports on the synthesis and amide bond linkage of carboxylic acid functionalized asymmetric zinc phthalocyanine (ZnPc) complexes to amino magnetic nanoparticles (AMNPs). The work further compares the photophysical and photochemical parameters of the Pc complexes alone with those linked to form ZnPc-AMNPs with further relation to the type of the spacer between the Pc and the AMNPs. Infrared spectroscopy confirmed the presence of the amide bond formed between the Pc complexes and the AMNPs. The triplet quantum yields ranged from 0.62 to 0.87. However, low singlet oxygen quantum yields were obtained due to competing pathways and the insufficient energy transfer from the excited triplet state of the ZnPc molecules to the molecular oxygen.