Carborane based chalcogen-fused phenazines for visible light induced ATRP

Area of Science:

• Materials Chemistry
• Organic Chemistry
• Photocatalysis

Background:

• Carborane derivatives and chalcogen-fused phenazines are classes of compounds with unique electronic properties.
• Metal-free photocatalysis offers a sustainable alternative to traditional catalytic methods.

Purpose of the Study:

• To synthesize novel carborane derivatives by combining o-carborane and chalcogen-fused phenazines.
• To investigate the photophysical and electrochemical properties of these new compounds.
• To evaluate their performance in metal-free photocatalytic atom transfer radical polymerization (ATRP).

Main Methods:

• Synthesis of o-carborane-chalcogen-fused phenazine derivatives (o-CB-DPEs).
• UV-Vis spectroscopy and cyclic voltammetry for property analysis.
• Spectroelectrochemistry and chemical oxidation for radical cation characterization.
• Atom Transfer Radical Polymerization (ATRP) experiments.

Main Results:

• Synthesized o-CB-DPEs exhibit visible light absorption (λ > 390 nm) and a narrow energy gap (~2.93 eV).
• Stable radical cation species were observed, with a long radical cation lifetime of 700 s for o-CB-DPS.
• o-CB-DPS demonstrated excellent performance in photocatalytic ATRP (Đ = 1.12, C(MMA) = 97%).

Conclusions:

• Combining carborane and chalcogen-fused phenazine moieties is a viable strategy to enhance photocatalytic efficiency.
• The synthesized o-CB-DPEs are promising candidates for metal-free photocatalytic applications, particularly in ATRP.
• The long-lived radical cation species are crucial for the observed high performance in photocatalysis.