A zinc(ii) metal–organic framework with high affinity for CO₂ based on triazole and tetrazolyl benzene carboxylic acid

Abstract

A new metal–organic framework {[Zn2(Htzba)2(dmtrz)]·(CH3)2NH}n (1) has already been solvothermally synthesized that exhibits a high CO2 uptake capacity.

Poly[bis(dimethylformamide-κO)-(μ8-5,5′′-dicarboxy-[1,1′:4′,1′′-terphenyl]-2′,3,3′′,5′-tetracarboxylato-κ8O:O1:O2:O3:O4:O5:O6:O7)dizinc(II)] — dimethylformamide (1/2), C18H19N2O8Zn

“…Each Zn(II) centre is five coordinated by four oxygen atoms (O1, O2, O5 and O6) derived from four different L 4− ligands and one oxygen atom (O7) derived from coordinated N,N-dimethylformamide molecule, resulting in a slightly distorted trigonal-bipyramid [ZnO5] coordination geometry. The bond angles around the Zn(II) atom vary from 86.29(13)°to 159.20(14)°, and the Zn-O bond distances range from 1.986(3) Å to 2.077(3) Å, which are consistent with the previously reported examples [7,8]. Moreover, it is worth noting that the sum of three bond angles O5-Zn1-O7, O7-Zn1-O6, O6-Zn1-O5 is exactly 360°, demonstrating the O5, O6 and O7 atoms are highly coplanar.…”

Octa- and Tetradecanuclear Mixed-Valent Vanadium(III/IV) Malates with Triazoles: Gas Adsorptions, Chiral Interface Recognition, and In Situ Decarboxylation

“…This enhanced affinity for CO 2 of 1 arises mainly from the channel rich in NH 2 -functionalized sites, which can generate a strong electrostatic interaction to facilitate selective CO 2 capture. , Especially, pairs of N atoms [such as N5···N5 a 5.601 Å, a ( y , x , 1 – z )] from amino groups of adjacent molecules in channels can act as molecular claws whose CO 2 dynamic sorption behavior has been confirmed by single-crystal X-ray diffraction . Also, the rich electrons from carboxyl groups and triazoles endow the channels with high polarizability, and strong quadrupole–quadrupole interactions occur between CO 2 and channels, resulting in the preferential affinity for CO 2 over other gases. − Since the isosteric heat of adsorption ( Q st ) is commonly used to evaluate the strength of the host–guest interaction between the framework and CO 2 , single-component adsorption performances of 1 for CO 2 at 25 and 15 °C were also recorded at 1 bar (Figure S9). Based on the Clausius–Clapeyron equation and Virial fitting method, the Q st value of CO 2 at zero coverage is calculated to be 24.83 kJ·mol –1 for 1 (Figure b), which is slightly higher than that functionalized with N-heterocycles such as MAF-26 (23.3 kJ·mol –1 ), and exposed cations such as Cu-BTTri (21.0 kJ·mol –1 ) .…”

“…40,41 Especially, pairs of N atoms [such as N5•••N5 a 5.601 Å, a(y, x, 1 − z)] from amino groups of adjacent molecules in channels can act as molecular claws whose CO 2 dynamic sorption behavior has been confirmed by single-crystal X-ray diffraction. 42 Also, the rich electrons from carboxyl groups and triazoles endow the channels with high polarizability, 43 and strong quadrupole−quadrupole interactions occur between CO 2 and channels, resulting in the preferential affinity for CO 2 over other gases. 44−46 Since the isosteric heat of adsorption (Q st ) is commonly used to evaluate the strength of the host−guest interaction between the framework and CO 2 , single-component adsorption performances of 1 for CO 2 at 25 and 15 °C were also recorded at 1 bar (Figure S9).…”

The State-of-the-Art Functionalized Nanomaterials for Carbon Dioxide Separation Membrane

“…A quadrupole-dipole interaction between CO 2 and polar groups is the main mechanism that contributed to this improvement [196,[226][227][228]. Similarly, a quadrupole-dipole interaction also contributes to the binding of CO 2 with many metallic compounds from the transition group, especially zinc, cobalt, copper and titanium [229][230][231] and nanomaterials that are rich with electronegative groups such as silica, titanium dioxide (TiO 2 ), GO and BN [32,124,208,232,233]. In addition, the formation of temporary sigma (σ) and pi (π) bonds between CO 2 and metal ion has been proposed [234].…”