Highly selective room temperature acetylene sorption by an unusual triacetylenic phosphine MOF

Abstract

The new ligand tris(p-carboxyphenylethynyl)phosphine (P{CCC₆H₄-4-CO₂H}₃) was used to synthesize a permanently porous Mn(II)-based acetylenic phosphine coordination material, PCM-48. This triply-interpenetrated MOF contains 1-D microchannels that are decorated with electron-rich and adsorbate-accessible acetylenic moieties and phosphine lone pairs. PCM-48 has a moderate room-temperature C₂H₂ adsorption capacity (25.54 cm³ g⁻¹) and displays high separation selectivities for C₂H₂ over CH₄ (C₂H₂/CH₄ = 23.3), CO₂ (C₂H₂/CO₂ = 4.3), and N₂ (C₂H₂/N₂ = 76.9) at 296 K.