Divergent Kinetic and Thermodynamic Hydration of a Porous Cu(II) Coordination Polymer with Exclusive CO₂ Sorption Selectivity

Abstract

Selective adsorption and separation of CO2 are of great importance for different target applications. Metal-organic frameworks (MOFs) represent a promising class of porous materials for this purpose. Here we present a unique MOF material, [Cu(tba)2]n (tba = 4-(1H-1,2,4-triazol-1-yl)benzoate), which shows high CO2 adsorption selectivity over CH4/H2/O2/Ar/N2 gases (with IAST selectivity of 41-68 at 273 K and 33-51 at 293 K). By using a critical point dryer, the CO2 molecules can be well sealed in the 1D channels of [Cu(tba)2]n to allow a single-crystal X-ray analysis, which reveals the presence of not only C(δ+)-H···O(δ-) bonds between the host framework and CO2 but also quadrupole-quadrupole (CO2(δ-)···(δ+)CO2) interactions between the CO2 molecules. Furthermore, [Cu(tba)2]n will suffer divergent kinetic and thermodynamic hydration processes to form its isostructural hydrate {[Cu(tba)2](H2O)}n and a mononuclear complex [Cu(tba)2(H2O)4] via single-crystal to single-crystal transformations.

A stable metal–organic framework with suitable pore sizes and rich uncoordinated nitrogen atoms on the internal surface of micropores for highly efficient CO2 capture

“…36 Its selectivity is evidently superior to most MOFs and this ranks NENU-520 among the highest selectivity values (Table S5 †) with the absence of unsaturated metal centres, charged units and amine groups. 46,[48][49][50][51][52][53][54][55][56][57] Thus, NENU-520 is one of the best materials to facilitate effective CO 2 capture and separation from the perspective of comprehensive properties.…”

“…3) [44][45][46] For the practical use of an adsorptive material, its regeneration and recycling properties are crucial and are also important standards to evaluate an adsorption material. Keeping this in mind, the regenerative feature of NENU-520a was investigated.…”

Syntheses and Crystal Structures of Three Cu(II) Coordination Polymers Based on 1,3,5-Tris(imidazol-1-yl)benzene and Benzene Carboxylate Ligands

“…Each Cu(II) ion is six-coordinated by three oxygen atoms from two different L3 4-anions and three nitrogen atoms from three individual timb ligands to form a distorted octahedral geometry and its basal plane is occupied by three oxygen atoms, O1, O3B and O4B, and one nitrogen atom, N3A, while the apical position is occupied by two nitrogen atoms (N1 and N5A). The Cu-O bond lengths are in the range of 2.0664(19)- Cu(HL1)(timb) (1) coordination mode makes the complex a 2D network with honeycomb structure, and a schematic drawing is shown in Fig. 3c.…”

“…The unique features of this type of materials, such as tunable structures, diversiform topologies, as well as potential applications in many useful areas, have made it a hot research topic for the scientist worldwide, especially for those who work in the field of crystal engineering [1][2][3][4][5][6][7][8].…”

Tuning Cadmium Coordination Architectures by Phenylenediacetate Position Isomers and 1,4‐Bis(benzimidazol‐1‐ylmethyl)benzene

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] To construct novel MOFs, many factors need to be considered, such as central metal ion, organic ligand, solvent, pH, and temperature. [14][15][16][17][18] Among those conditions, selection of appropriate organic ligands may be a prerequisite to obtain the target products.…”