Synthesis of functionalized iron N-heterocyclic carbene complexes and their potential application as flame behavior modifier in cross linked epoxy resins

The design of new flame retardants (FR) that avoid the use of halogen and phosphorus additives is challenging and urgent. Herein we report on the synthesis of bis-amino functionalized N-heterocyclic carbene cyclopentadienone iron complexes aimed at promoting the production of iron containing epoxy resins. Iron complexes are successfully employed to obtain high Tg thermosets with as low as 5% hardener content. Moreover the obtained resins display an impressive charring ability that paves the way to the application of such systems for material with improved flame behavior.