Two isomeric Zn(II)-based metal-organic frameworks constructed from a bifunctional triazolate-carboxylate tecton exhibiting distinct gas sorption behaviors

Two isomeric Zn(II)-based metal-organic frameworks, {[Zn(CPT)(2)](NMF)(3)}(n) (1) and {[Zn(CPT)(2)](DMF)(0.75)}(n) (2) (HCPT = 4-(4-carboxyphenyl)-1,2,4-triazole, NMF = N-methylformamide, DMF = N, N-dimethylformamide), with the same 4-fold interpenetrated dia topological network have been prepared under solvothermal conditions by employing a bifunctional triazolate-carboxylate organic linker, which show very similar voids but different pore shapes. Thermogravimetry, powder X-ray diffraction, molecular mechanics calculation, and gas sorption studies revealed their different framework stabilities and flexibilities, in which desolvated 1 exhibits temperature-dependent stepwise and hysteretic selective sorption of CO2 over N-2 at 195 K, whereas desolvated 2 could adsorb neither CO2 nor N-2. Furthermore, the luminescence properties of 1 and 2 were investigated.