Photoswitching CO₂ Capture and Release in a Photochromic Diarylethene Metal–Organic Framework

Abstract

We demonstrate herein a promising pathway towards low-energy CO2 capture and release triggered by UV and visible light. A photosensitive diarylethene ligand was used to construct a photochromic diarylethene metal-organic framework (DMOF). A local photochromic reaction originating from the framework movement induced by the photoswitchable diarylethene unit resulted in record CO2-desorption capacity of 75% under static irradiation and 76% under dynamic irradiation.

Two-Photon Responsive Metal–Organic Framework

“…Light responsive MOFs, whose chemical and structural changes can be controlled merely by mild condition-light irradiation, have shown intriguing properties, and thus recently received great interest. [17][18][19][20][21][22][23][24][25][26][27][28] For example, light can induce configuration transformations of the linkers/guests, thus to tune the pores of MOFs and enhance their gas separation performances. [18][19][20][21] Photochemical reactions can also provide an alternative way to introduce functional groups/moieties and thus to develop smart MOFs with switchable optical absorption and fluorescence properties.…”

“…[17][18][19][20][21][22][23][24][25][26][27][28] For example, light can induce configuration transformations of the linkers/guests, thus to tune the pores of MOFs and enhance their gas separation performances. [18][19][20][21] Photochemical reactions can also provide an alternative way to introduce functional groups/moieties and thus to develop smart MOFs with switchable optical absorption and fluorescence properties. [21][22][23][24][25] Because the light triggers the reactions in a one-photon process in these examined systems, we were not able to develop their spatial selectivity: the photochemical responses take place either on the surfaces or in the whole crystals of MOFs.…”

“…[18][19][20][21] Photochemical reactions can also provide an alternative way to introduce functional groups/moieties and thus to develop smart MOFs with switchable optical absorption and fluorescence properties. [21][22][23][24][25] Because the light triggers the reactions in a one-photon process in these examined systems, we were not able to develop their spatial selectivity: the photochemical responses take place either on the surfaces or in the whole crystals of MOFs. It is essential to engineer the properties of MOFs using the light or laser in 3-dimensional (3D) structure, which would create functional patterns inside the MOF crystals and find applications in chemical sensors, optical switches, data storage and circuits.…”

Intramolecular Hydrogen Bonds Enhance Disparity in Reactivity between Isomers of Photoswitchable Sorbents and CO2: A Computational Study

“…In recent years, photoswitchable molecules such as azo compounds, [7][8][9][10] N-salicylidene aniline, [11] and dithienylethene [12][13][14] ( Figure 1) have attracted significant attention, owing to their unique capability of instantly switching configurations between cis and trans isomersu pon irradiation and/orh eating. The corresponding properties can varys ubstantially.F or example, the molecular length of azobenzene's cis and trans isomers differs by 5.5.O wing to large geometry changes like this, azobenzene has recently been incorporated into poroush osts for gas separation purposes,i ncluding metal-organic frameworks, [15][16][17] mesoporous silica, [18,19] and porousc oordination…”

“…[14][15][16] The chemical property differences have not been fully exploited for designing CO 2 removal reagents. On the otherh and, the chemistry between the sorbents and CO 2 has been studied thoroughly.D uring the past decade, av ariety of CO 2 capture materials such as taskspecific ionic liquids( ILs) [21][22][23][24][25][26][27] and porous solids [28][29][30][31] have been developed, which have not only successfully avoided many disadvantages of industrially used aqueous amines, [32][33][34][35][36][37] but can also be compositionally and structurally tuned to achieve highly efficient CO 2 capture.…”