Styrene Polymerization under Ambient Conditions by using a Transient 1,3,2-Diazaphospholane-2-oxyl Complex

Area of Science:

• Organometallic Chemistry
• Polymer Chemistry
• Radical Polymerization

Background:

• The development of efficient radical initiators is crucial for polymer synthesis.
• Tungsten carbonyl complexes offer unique reactivity profiles.
• TEMPO-based radicals are well-established polymerization mediators.

Purpose of the Study:

• To synthesize and characterize a novel P-OTEMP substituted 1,3,2-diazaphospholane W(CO)5 complex.
• To investigate the thermal stability and reactivity of the O-N bond within the complex.
• To explore the potential of this complex as a radical initiator for polymerization.

Main Methods:

• Combined theoretical (DFT) and experimental studies.
• Synthesis and characterization of the tungsten complex.
• Kinetic studies of styrene polymerization.

Main Results:

• The W(CO)5 complex features a thermally labile O-N bond.
• Homolytic cleavage of the O-N bond generates a transient 1,3,2-diazaphospholane-2-oxyl radical complex.
• This radical complex effectively initiates styrene polymerization under ambient conditions.

Conclusions:

• The novel tungsten complex serves as a precursor to a radical initiator.
• The facile generation of radicals from the complex enables controlled polymerization.
• This work expands the scope of radical initiators for polymer synthesis.