Selective CO2 adsorption and theoretical simulation of a stable Co(II)-based metal-organic framework with tunable crystal size

A three-fold interpenetrated metal-organic framework [CO2(OBA)(4)(PTD)center dot 3DMF center dot CH3CH2OH center dot 5H(2)O](n) (1) has been synthesized by utilizing 4,4'-oxybis(benzoic acid) (H(2)OBA) as the linker, 6-(pyridin-4-yl)-1,3,5-triazine-2,4-diamine (PTD) as the ligand, and CoCl2 center dot 6H(2)O via solvothermal method. Compound 1 exhibits not only a high uptake capacity for CO2 molecules with an estimated high sorption heat (50.6 kJ mol(-1) at zero loading), but also a significant selective adsorption of CO2 over CH4, which may be ascribed to the presence of proper-sized pores with high polarity, amine groups and triazine rings of PTD linker decorating the pores. Meanwhile, the Grand Canonical Monte Carlo (GCMC) simulations of CO2 adsorption of compound 1 demonstrate that CO2 molecules are preferentially adsorbed around the PTD ligands. Furthermore, complex 1 displays a relatively high adsorption capacity of H-2 (101.7 cm(3) g(-1) at 1 bar) under 77 K.