Two porous Ni-MOFs based on 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine showing solvent determined structures and distinctive sorption properties toward CO2 and alkanes

By regulating the solvent used for synthesis, two porous Ni-MOFs, namely {[Ni-3(BTC)(2)(TPT)(2/3)(H2O)(4.08)(MeOH)(0.92)]center dot 2DMF center dot 0.5H(2)O center dot 0.5MeOH}(n) (1) and {[Ni-3(BTC)(2)(TPT)(2)(H2O)(6)]center dot 6DMF}(n) (2) (H3BTC = 1,3,5-benzenetricarboxylic acid, TPT = 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine, DMF = N,N-dimethylformamide, and MeOH = methanol) were obtained. Compound 1 reveals a rigid 3D framework, while compound 2 shows a flexible 3-fold interpenetrated framework. Compound 1 exhibits a selective adsorption of CO2 due to the sieving effect of the rigid framework containing two types of cages with small apertures. Noteworthily, the flexible compound 2 displays an obviously guest-induced structural transformation. The desolvated compound 2 reveals a much higher capacity toward CO2 and n-C4H10 than those of N-2 CH4, C2H6 and C3H8.

Automated summary

By regulating the solvent used for synthesis, two porous Ni-MOFs materials were obtained, with compound 1 having a rigid 3D framework and selective adsorption of CO2, and compound 2 showing a flexible 3-fold interpenetrated framework with higher adsorption capacity for CO2 and n-C4H10 after desolvation.