Porous Liquids Responsive to Light**

Abstract

Porous liquid is a unique liquid medium that combines permanent porosity of porous solid with the uidity of liquid, and this special characteristic makes it potential in various applications. Here we report the rst photoresponsive porous ionic liquid (PPIL) by solubilizing photoresponsive metal-organic polyhedron (PMOP, constructed from dicopper and azobenzene-containing carboxylate) in polyethyleneglycol-functionalized bulky ionic liquid (IL). Owing to favorable ion interactions, bulky IL molecules encircle outside PMOP cages, and the inter cavities are maintained. The azobenzene moieties can be isomerized freely in the obtained PPILs to expose and shelter active sites upon visible and UV light irradiations. Hence, the adsorption capacity of PPILs is controllable by light irradiation, and the change in CO 2 uptake is up to 30% which is different from neat IL with negligible change. This study might inspire the development of new adsorption process regulated by light instead of conventional pressure and temperature swing adsorption technologies. Full TextPorous liquids have drawn increasing attention owing to the combination of porous solid and uid which furnishes resulting owing system eternal porosity. [1][2][3][4] The permanent pores endow uids with subsidiary physicochemical properties, rendering as suitable solitary media for a variety of applications like adsorption and catalysis. [5][6][7] Intrinsic cavities in uidic systems can be generated by three methods, that is, porous hosts' functionalization (type I) as well as their solubilization (type II) or dispersion (type III) in relatively size-excluded solvents. [8][9][10] In present, basic entities for rigid host structures are mostly from metal-organic frameworks, porous organic cages and zeolites, while chlorinated solvents and ionic liquids (ILs) are chosen as sterically hindered solvents. [11][12][13][14][15] Such combinations lead to the formation of a series of interesting porous liquids.Life systems are capable of modulating themselves to variable environments for survival. Inspiring by this, smart materials that can respond to external stimuli (e.g. temperature, light, and pH) with tunable features have been developed. [16][17][18][19][20] Among various external stimuli, light attracts great interest since it allows rapid and precise control with rare undesirable byproducts. [21][22][23][24] Azobenzene is a classic photoresponsive molecule, its con guration transformation between cis and trans isomer can be induced by ultraviolet (UV) and visible light irradiation. [25][26][27] On the basis of such con guration transformation, it is promising to construct azobenzene-based materials with tunable performance through sheltering and exposing active sites. [28][29][30][31][32] By introducing photoresponsive porous moieties to bulky liquids, it is expected to endow the uids with properties responsive to light. As a result, the adsorption process is possible to run by light irradiation, which is remotely controllable and much more energy-e cient in compar...

Porous Liquids Open New Horizons: Synthesis, Applications, and Prospects

“…Additionally, the flowing ability of PLs provides enormous convenience for the industrial pumping process . Thus, PLs have shown enormous potential in a plethora of applications ranging from gas selective sorption, membrane separation, homogeneous catalysis, chiral separation to biomedical science, etc. − As shown in Figure , research progress has successively witnessed achievements in both synthesis protocols and application extensions although the period of development is relatively short, especially the past four years that have demonstrated that the “dam” for PLs has burst . Additionally, the establishment of the company “Porous Liquid Technologies” unquestionably accelerates the pace of commercialization toward practical applications.…”

Transformation of Type III to Type II Porous Liquids by Tuning Surface Rigidity of Rhodium(II)‐Based Metal‐Organic Polyhedra for CO2 Cycloaddition

“…[14][15][16] Type II PL system, which can be prepared by dissolving porous host in size-excluded solvent is beneficial with its facile synthesis, handing during the analytical process, storage and durability as well as usage. [17][18][19][20] However, only a limited number of porous hosts are employed for type II PLs and there is a need to focus on unexplored porous solids and bulky solvents. Considering porous hosts, there is another category known as MOPs.…”

Underlying potential evaluation of the real-process applications of magnetic porous liquids

“…This method can be subject to light absorption by the liquid, limited passage of light within the liquid, and the possibility of photodegradation of the liquid and/or the MOFs. 41,42 Other external stimuli that have been recently applied to promote PL regeneration include shearing and heating. The efficacy of this method can be constrained by its sensitivity to uctuations under environmental conditions, as well as concerns regarding its resilience over time.…”