Vapor sorption behavior in heptazine-based MOF featuring a brick-shaped framework

A new porous MOF, [Mg1.5(HTB)2]center dot 2Me2NH2 center dot 3DMF center dot 12MeOH, (1) (HTB = s-heptazine tribenzoate) was successfully synthesized by employing a n-conjugated organic ligand possessing a brick-shaped framework. The activated 1a was investigated as an adsorbent towards a series of vapors (H2O, MeOH, EtOH, n-PrOH and CH2Cl2). The H2O vapor adsorption capacity of 1a can reach 533.9 cm3 g-1. Interesting, the absorption isotherm of MeOH shows an obvious stepwise sorption phenomenon with the saturated adsorption capacity of 300.8 cm3 g-1, whereas the bulker EtOH, n-PrOH and CH2Cl2 present hardly any uptakes. Moreover, the IAST selectivities of equimolar H2O/MeOH and H2O/EtOH vapor mixtures was calculated, GCMC simulations were performed to locate the framework-vapor binding sites.

Automated summary

A new porous MOF with a brick-shaped framework was synthesized successfully, and it showed high adsorption capacity for H2O and MeOH, while low adsorption capacity for EtOH, n-PrOH, and CH2Cl2. The adsorption selectivity and binding sites of the material were determined through simulation calculations.