Iron Coordination to Hollow Microporous Metal-Free Disalphen Networks: Heterogeneous Iron Catalysts for CO2 Fixation to Cyclic Carbonates.

This work shows that a hollow and microporous metal-free N,N'-phenylenebis(salicylideneimine) (salphen) network (H-MSN) can be engineered by Sonogashira coupling of [tetraiodo{di(Zn-salphen)}] building blocks with 1,4-diethynylbenzene in the presence of silica templates and by successive Zn and silica etching. Iron(III) ions could be incorporated into the H-MSN to form hollow and microporous Fe-disalphen networks (H-MFeSN) with enhanced microporosity and surface area. The H-MFeSN showed efficient catalytic performance and recyclability in the CO2 conversion to cyclic carbonates.