Investigation of photocatalytic properties of cobalt phthalocyanines on benzyl alcohol photoxidation

Abstract

Photocatalysis is a fast and economically attractive option for oxidation reactions. Herein, 4‐(5‐iodopyridin‐2‐yloxy)phthalocyaninato cobalt(II) (P‐CoPc) and 4‐(4‐methylquinolin‐2‐yloxy)phthalocyaninato cobalt(II) (Q‐CoPc) were synthesized and characterized with spectroscopic data (FT‐IR, UV‐Vis, and mass spectra). The parameters affecting the photocatalytic activity such as substrate amount, oxidant type, substitution group, and solvent effect were studied. Both catalysts show high benzaldehyde selectivity with high TON and TOF values (470 and 1880 forP‐CoPcand 375 and 1500 forQ‐CoPc, respectively). The best photoxidation conditions were determined that 1/1500/500 (cat/subs./ox. ratio) in DMSO and in the presence of light. Aggregation and photodegradation studies ofP‐CoPc and Q‐CoPchave also carried out in this work.