Selectivity Adsorption and Photoswitching Low Energy Release of C2H2 in a Diarylethene Metal-Organic Framework

The separation as well as low energy storage and release of C2H2 remains a major challenge in industry. The use of metal-organic frameworks (MOFs) is an appealing path to achieve effective separation or storage of C2H2; however, no obvious report processes high capture and separation performance, as well as low energy release of C2H2 simultaneously, because of the contradictions in adsorption thermodynamics. This work successfully developed an effective photoisomerization strategy and achieved C2H2 high selectivity adsorption and photoswitchable low energy release simultaneously in a proof-of-concept adiarylethene functional MOF [Zn-2(SDC)(2)(BPMTC), denoted as 1]. The pores in 1 with multiple functional sites enhance the interactions with C2H2 molecules and endowing significant selectivity for C2H2 over CO2. An unprecedented pore size tuning originating from the framework photoisomeric induced by the photoswitchable diarylethene unit resulted in low-energy-cost C2H2 desorption. This finding will inspire design and synthesis of MOFs for highly efficient high capture and separation performance, as well as low energy release of C2H2.