Two highly stable isoreticular M 8 -pyrazolate (M = Co, Ni) metal-organic frameworks for CO 2 conversion.

Two isoreticular metal-organic frameworks (MOFs) constructed from M 8 (OH) 4 (H 2 O) 2 (pyz) 12 (M = Co, Ni; pyz = pyrazolate) secondary building units (SBUs) and Ni(salen)-derived metalloligands were synthesized. The two MOFs were found to be highly stable in a wide pH and temperature range. Together with the tetrabutylammonium bromide (TBAB) co-catalyst, they catalysed the cycloaddition of CO 2 to epoxides with near-quantitative yields and easy recyclability for at least 11 cycles.