Post-complexation Functionalization of Cyclometalated Iridium(III) Complexes and Applications to Biomedical and...

Area of Science:

• Organometallic Chemistry
• Materials Science
• Photochemistry

Background:

• Cyclometalated iridium(III) complexes possess advantageous photophysical properties like high quantum yields and long emission lifetimes.
• Existing synthesis methods limit the incorporation of thermally sensitive functional groups due to harsh reaction conditions.
• These limitations hinder the development of advanced iridium(III) complexes for specialized applications.

Purpose of the Study:

• To review and highlight the significance of post-complexation functionalization (PCF) for iridium(III) complexes.
• To explore the synthesis of iridium(III) complexes with tailored properties via PCF.
• To summarize the diverse biological and material applications enabled by PCF.

Main Methods:

• Focuses on functionalization strategies applied *after* the formation of the cyclometalated iridium(III) core.
• Discusses methods enabling the attachment of various functional groups, including thermally labile ones.
• Reviews the subsequent characterization and application testing of the modified complexes.

Main Results:

• PCF overcomes the limitations of pre-functionalization, allowing the incorporation of sensitive groups like peptides and sugars.
• Successfully synthesized iridium(III) complexes with tunable emissions (blue-red, white) and long lifetimes.
• Demonstrated applications in developing luminescence pH probes, cancer cell imaging agents, and anticancer compounds.

Conclusions:

• Post-complexation functionalization (PCF) is a versatile strategy for creating advanced iridium(III) complexes.
• PCF significantly broadens the scope of applications for iridium(III) complexes in both material science and biological fields.
• This approach facilitates the development of sophisticated luminescent probes and therapeutic agents.