Design of robust rod-packing [In(OH)(BDC)] frameworks and their high CO2/C2-hydrocarbons over CH4 separation performance

Solvent-Regulated Formation of Metal/Metal-Oxo Nodes in Two Indium Metal-Organic Frameworks: Syntheses, Structures, Selective Gas Adsorption and Fluorescence Sensor Properties

Two water-stable indium metal-organic frameworks, (NH2Me2)3[In3(BTB)4] ⋅ 12DMA ⋅ 4.5H2O (In-MOF-1) and (NH2Me2)9[In9O6(BTB)8(H2O)4(DMSO)4] ⋅ 27DMSO ⋅ 21H2O (In-MOF-2) (BTB=4,4',4''-benzene-1,3,5-tribenzoate) with 3D interpenetrated structure has been constructed by regulating solvents. Structure analysis revealed that In-MOF-1 has a three-dimensional (3D) structure with a single metal core, while In-MOF-2 features an octahedron cage constructed by three kinds of metal clusters to further form a 3D structure. The fluorescence investigations showed that In-MOF-1 and In-MOF-2 are potential MOF-based fluorescent sensors to detect acetone and Fe3+ ions in EtOH or water with high sensitivity, excellent selectivity, recyclability and a low limit of detection. Moreover, the fluorescence mechanisms of In-MOF-1 and In-MOF-2 toward acetone and Fe3+ ions were further explained. In addition, In-MOF-2 has higher thermal and framework stability than In-MOF-1. The activated In-MOF-2 presents a high BET surface area of 998.82 m2g-1 and a pore size distribution of 8 to 16 Å. At the same time, In-MOF-2 exhibits high selective CO2 adsorption for CO2/CH4 and CO2/N2, respectively. Furthermore, the adsorption sites and adsorption isotherms were predicted using grand canonical Monte Carlo (GCMC) simulations, and the adsorption energy of the lowest-energy adsorption configuration was calculated using molecular dynamics (MD) simulations.

Self-Interpenetrated Water-Stable Microporous Metal-Organic Framework toward Storage and Purification of Light Hydrocarbons

Storage and purification of light hydrocarbons are very meaningful for their high-purity requirements and safety utilization in the fields of industry and clean energy. It is a simple and effective way to achieve this goal utilizing the physical adsorption properties of stable porous metal-organic frameworks (MOFs). In this work, a stable self-interpenetrated three-dimensional MOF with a new 3,4-connected topology, {[Zn₂(tpda)₂(4,4'-bpy)]·4DMF}_n (NKM-101; H₂tpda = 4,4'-[4-(4H-1,2,4-triazol-4-yl)phenyl]dibenzoic acid, 4,4'-bpy = 4,4'-bipyridine, and DMF = N,N-dimethylformamide), has been successfully constructed based on a triazole-carboxyl ligand. The dense functional active sites existing on the inner walls of one-dimensional channels of NKM-101 are beneficial to enhancement of the binding affinities between the framework and specific molecules (CO₂, C₂-C₄). Therefore, the selective adsorption and separation performance of the material on CO₂/CH₄ and C₂-C₄/CH₄ are effectively improved. In addition, NKM-101 also exhibits excellent water stability, making it possible to be a practical material for the storage and purification of light hydrocarbons.