Two highly stable isoreticular M₈-pyrazolate (M = Co, Ni) metal-organic frameworks for CO₂ conversion

Two isoreticular metal-organic frameworks (MOFs) constructed from M-8(OH)(4)(H2O)(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 CO2 to epoxides with near-quantitative yields and easy recyclability for at least 11 cycles.