Computational Studies on Selective Adsorption and Molecular Sieving in HKUST-1 Metal – Organic Framework
- Metal organic frameworks (MOFs) bring new possibilities by their potential use in catalysis, gas storage/separation and drug delivery.[1-8]
HKUST-1 consists of Cu2+ ions-connectors and four organic ligands. Open metal sites present in the structure have tremendous impact on the selective adsorption. Showing this is the scope of the studies presented in this thesis.
The guest molecules were chosen basing on the possible applications of HKUST-1. It might serve as an air and water purifying agent (from small gases, niacin and urea) or molecular sieve (for separation of small hydrocarbons).
The results of our research suggest that the adsorption of small gases should be performed in a dry environment, otherwise the copper centers will be blocked by water. In case of separation of aromatic hydrocarbons or biologically important molecules, this does not take place.
The defects in the framework have also been taken into account. Thus, the additional calculations with the defective models have been performed. Results show stronger binding of the guests to the defective site, than the non-defective ones.
Investigation of the changes in the IR spectrum after adsorption allowed to confirm and distinguish the binding mechanism.
The research were performed with DFT, using B3-LYP functional [9,10] and the TZVP basis set (Turbomole program), and two for Gaussian: 6-311G(d) for the non-defective structures and mixed[11] (for the defective ones).
1 Lee et al., Chem. Soc. Rev., 2009, 38, 1450
2 Murray et al., Chem. Soc. Rev., 2009, 38, 1294
3 Li et al., Chem. Soc. Rev.,2009, 38, 1477
4 Bonino et al., Chem. Mater., 2008, 20, 4957
5 Britt et al., P. Natl. Acac. Sci. USA, 2008, 105, 11623
6 Dietzel et al., Chem. Commun., 2008, 5125
7 Caskey et al., J. Am. Chem. Soc., 2008, 130, 10870
8 Valenzano et al., J. Phys. Chem. C, 2010, 114, 11185
9 Becke, Phys. Rev. A , 1988, 38, 3098
10 Lee et al., Phys. Rev. B, 1988, 37, 785
11 Roy et al., J. Chem. Theory. Comput., 2008, 4, 1029