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Host–guest and guest–guest interactions between xylene isomers confined in the MIL-47(V) pore system
- Source :
- THEORETICAL CHEMISTRY ACCOUNTS
- Publication Year :
- 2012
- Publisher :
- Springer Science and Business Media LLC, 2012.
-
Abstract
- The porous MIL-47 material shows a selective adsorption behavior for para-, ortho-, and meta-isomers of xylenes, making the material a serious candidate for separation applications. The origin of the selectivity lies in the differences in interactions (energetic) and confining (entropic). This paper investigates the xylene-framework interactions and the xylene-xylene interactions with quantum mechanical calculations, using a dispersion-corrected density functional and periodic boundary conditions to describe the crystal. First, the strength and geometrical characteristics of the optimal xylene-xylene interactions are quantified by studying the pure and mixed pairs in gas phase. An extended set of initial structures is created and optimized to sample as many relative orientations and distances as possible. Next, the pairs are brought in the pores of MIL-47. The interaction with the terephthalic linkers and other xylenes increases the stacking energy in gas phase (-31.7 kJ/mol per pair) by roughly a factor four in the fully loaded state (-58.3 kJ/mol per xylene). Our decomposition of the adsorption energy shows various trends in the contributing xylene-xylene interactions. The absence of a significant difference in energetics between the isomers indicates that entropic effects must be mainly responsible for the separation behavior.
- Subjects :
- Stacking
Xylenes
010402 general chemistry
7. Clean energy
01 natural sciences
Separation
DENSITY-FUNCTIONAL THEORY
METAL-ORGANIC FRAMEWORKS
Molecular dynamics
chemistry.chemical_compound
Adsorption
Non-covalent interactions
Organic chemistry
Physical and Theoretical Chemistry
chemistry.chemical_classification
SELECTIVE ADSORPTION
010405 organic chemistry
Chemistry
BENZENE DIMER
Xylene
SANDWICH
MIL-47
DFT-D
PI-STACKING INTERACTIONS
0104 chemical sciences
Physics and Astronomy
MOLECULAR-DYNAMICS
Chemical physics
Selective adsorption
Density functional theory
Metal-organic framework
NONCOVALENT INTERACTIONS
Subjects
Details
- ISSN :
- 14322234 and 1432881X
- Volume :
- 131
- Database :
- OpenAIRE
- Journal :
- Theoretical Chemistry Accounts
- Accession number :
- edsair.doi.dedup.....f73a429805bdf5f7b32ef3d61b4bb6cc