Amino-decorated zinc bipyrazolate MOFs, an example of carbon dioxide capture and reuse (CCR)

Carbon dioxide emissions in atmosphere have been increasing more and more since the Industrial Revolution due to anthropogenic activities. It is well known that this gas is responsible for global warming and, indirectly, of depletion of stratospheric ozone; moreover, the increase of CO2 concentration in waters is causing the acidification of oceans with negative consequences on sea life. Metal-Organic Frameworks (MOFs) seem to be a valid solution to counteract this fast growth, due to the surprising ability of some MOFs in selective adsorption of CO2, in its storage and also conversion into other products (Carbon Dioxide Capture and Reuse, CCR). In this communication, two isomeric forms of diamino-decorated zinc bipyrazolate MOFs Zn(3,3'-L) and Zn(3,5-L) (L = diamino-4,4'-bipyrazolate) have been synthesized by solvothermal route in DMF and characterized by IR, TGA/DTA, EA. XRPD analysis shows in both cases 3D (4,4)-connected network structures with 1D squared channels, isostructural with respect to Zinc MOFs based on 3-amino-4,4'-bipyrazole and 4,4'-bipyrazole linkers previously reported.The textural properties (BET surface area, pore size distribution) and the ability as CO2 adsorbents were investigated through N2 and CO2 adsorption, together with their potential as heterogeneous catalysts in the solvent-free conversion of epichlorohydrin or epibromohydrin and carbon dioxide into the corresponding cyclic carbonates at 393K and pCO2 = 5 ba.