CO2 selective dynamic two-dimensional ZnII coordination polymer

Abstract

A CO2 selective dynamic two-dimensional (2D) MOF system, [Zn(glu)(μ-bpe)]·2H2O (·2H2O) (glu = glutarate, bpe = 1,2-bis(4-pyridyl)ethylene), is prepared. Based on variable temperature PXRD patterns, I·2H2O exhibits a structural transformation of the framework upon desolvation. Various gas sorption analyses at low temperatures reveal that solvent-free I selectively adsorbs CO2 over N2, H2, and CH4. Stepped CO2 isotherms for solvent-free I with a large hysteresis between adsorption and desorption branches at 196 K indicate that I is a dynamic framework. Moreover, I·2H2O shows efficient heterogeneous catalytic reactivity for transesterification of various esters. The catalyst can be recycled multiple times without losing its original activity.

Two new NiII and ZnII metal–organic frameworks of glutarate and 1,4-bis[(2-methyl-1H-imidazol-1-yl)methyl]benzene ligands: syntheses, structures and luminescence sensing properties

“…Glutaric acid, as a flexible aliphatic dicarboxylic acid, is an excellent multidentate bridging ligand for the construction of coordination structures due to its flexibility and conformational freedom (Bhattacharya et al, 2014;Hwang et al, 2013;Low & LaDuca, 2015). For the semi-rigid 1,4-bis[(2-methylimidazol-1-yl)methyl]benzene ligand (1,4-mbix), due to the existence of two -CH 2 -groups in the molecule, it prefers to form an M 2 L 2 metallocyclic ring when adopting a cis conformation, which is of benefit for generating polyrotaxane and polycatenate nets, whereas higher dimensional networks are formed when 1,4-mbix adopts the trans conformation (Liu et al, 2009).…”

Experimental and Theoretical Investigations of CO2 Sorption by a 3D In‐MOF with Multiple 1D Channels

“…This kind of phenomenon is usually accompanied by well‐defined, stepped CO 2 isotherms above the gate‐opening pressure. We also previously observed a sudden increase in the amount of CO 2 uptake at around 0.68 atm due to the flexible nature of solvent‐free 2D framework [Zn(glu)(μ‐bpe)] · 2H 2 O {glu = glutarate, bpe = 1,2‐bis(4‐pyridyl)ethylene} 16. Interestingly, however, the step in the adsorption isotherm for [Zn(glu)(μ‐bpe)] · 2H 2 O was only observed at 196 K. Upon increasing the sorption temperature to 243 K, the clear step completely disappeared.…”

Three‐Dimensional Co‐ and Mn‐MOFs Containing a C2h‐Symmetric Terphenyl‐3,3′‐dicarboxylate Linker and Their Magnetic Properties

“…We also expected the MOFs to exhibit breathing behavior in the adsorption of gas at low pressure. However, unlike other MOFs that show breathing behavior at low pressure upon the loss of solvate molecules from as‐prepared MOFs such as 3D [Zn 2 (bme‐bdc) 2 (dabco)] [bme‐bdc = 2,5‐bis(2‐methoxyethoxy)‐1,4‐benzenedicarboxylate] and 2D [Zn(glu)(µ‐bpe)] · 2H 2 O [glu = glutarate; bpe = 1,2‐bis(4‐pyridyl)ethylene], MOFs I and II did not breathe once the bridging dmf ligands had been removed, which indicates that the transformed structures after activation may maintain relatively rigid frameworks compared with other 2D of 3D breathing systems.…”

“…The structural transformation of the original framework into a new one affects the magnetic and gas‐sorption properties of the resulting MOF. The pressure‐dependence of gas sorption of breathing MOF systems is a good example , . Meanwhile, there are several examples of MOF systems that experience a change in their magnetic properties upon a change in the framework or coordination environment of the metal center.…”