A Quinary Metal–Organic Framework Composed of One Metal and One Linker with Ethane-Selective Property

Solvothermal reaction between Fe₃O(CH₃COO)₆(H₂O)₃ and terphenyl-3,3′’,5,5′’-tetracarboxylic acid (H₄TPTC) afforded a scarce multinary MOF of Quin-Fe-TPTC (Quin and TPTC are abbreviated from quinary and terphenyl-3,3′’,5,5′’-tetracarboxylate, respectively), which exemplifies the first quinary MOF comprising one metal and one linker in contrast to the documented ones assembled from one metal and four linkers or two metals and three linkers. The variation of linker aspect ratio and the deformation of the trinuclear iron cluster may be responsible for creating such a compound. Quin-Fe-TPTC exhibits bihelical channels interconnected through (hemi) cage cavities replete with methyl groups, resulting in C₂H₆-selective adsorption from a binary C₂H₆ and C₂H₄ mixture and benefiting one-step C₂H₄ purification. This was validated by not only IAST prediction but also by dynamic column breakthrough experiments.