Two CuxIy-based copper–organic frameworks with multiple secondary building units (SBUs): structure, gas adsorption and impressive ability of I2 sorption and release

Abstract

Two Cu_xI_y-based copper–organic frameworks with multiple secondary building units (SBUs), [(Cu₄I₄)₈(Cu₈I₆)(Dabco)₈Cu₁₂L₂₄DMF₁₂]·2NO₃⁻·17DMF (1) and [(Cu₄I₄)CuL₂(Dabco)_1.5]·10H₂O·2DMF (2) (Dabco = 1,4-diazabicyclo[2.2.2]octane, H₂L = 4-pyridylbenzoate, DMF = N,N-dimethylformamide), have been successfully synthesized under solvothermal conditions and structurally characterized. Compound 1 possesses a 24-connected twisty truncated cuboctahedra supermolecular building block (SBB) constructed from a rare Cu₈I₆ cluster and 8 tetrahedral Cu₄I₄ SBUs, which is the first reported SBB based on Cu_xI_y clusters. Compound 2 is a doubly interpenetrated MOF based on Cu₄I₄ and Cu-paddlewheel SBUs with a (4,6)-connected network. It is worth noting that the BET surface area of compound 2 ranks highly among the Cu_xI_y-based MOF materials. In addition, both compounds exhibit high performance for I₂ sorption and release.