A complex comprising one [Re(CO)3]+ unit and a phthalocyanine (Pc) ligand (Re1Pc) is shown to function as a photo-induced CO-releasing molecule (photoCORM) in the presence of O2 and a coordinative solvent under irradiation with red light, which can deeply penetrate living tissues. Transient absorption spectroscopic measurements indicate very short excited-state lifetimes and ultrafast intersystem crossing for Re1Pc and Re2Pc, which contains two [Re(CO)3]+ units. The excited-state properties are ascribed to efficient spin–orbit coupling and large Franck–Condon factors originating from the complexes’ distorted structures, that is, unsymmetric coordination of [Re(CO)3]+ unit(s), one of which was confirmed by single-crystal X-ray analysis of a symmetrically substituted Pc with two [Re(CO)3]+ units. Re1Pc represents a promising red-light-driven photoCORM that can be applied in biological environments or therapeutic applications.
All Science Journal Classification (ASJC) codes
- Organic Chemistry