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

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.