Synthesis of Ordered Carbonaceous Framework with Microporosity from Porphyrin with Ethynyl Groups

One of the challenging targets in materials synthesis is a direct conversion of molecular based crystalline substances into crystalline ordered carbonaceous frameworks (OCFs). Though we have discovered the first example of the direct conversion with Ni-cyclic porphyrin dimer bridged by diacetylene moieties, such dimer requires a multi-step synthesis procedure with low yield and the resulting OCFs are not highly porous. Herein, we report the direct conversion of Ni-porphyrin monomer with ethynyl groups into OCF with developed microporosity. Upon heat-treatment, Ni-porphyrin monomer is thermally polymerized via ethynyl groups and the resulting polymer is successively converted into OCF at 873 K. Thus, ordered microporous material with conductive carbonaceous framework is obtained. The porphyrin Ni-N-4 coordination structure is well retained after the carbonization and the microporous OCF exhibits specific electrocatalysis for CO2 conversion into CO with high selectivity.