Nature of forces responsible for stacking interactions

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Chhikara, Aditya
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Lethbridge, Alta. : University of Lethbridge, Dept. of Chemistry and Biochemistry, 2010
Stacking interactions, also known as π-π or face-to-face interactions, occur between molecules whose π bonds are in parallel planes. They are used to design self-assembling structures in nanotechnology, influence organic reactions and are ubiquitous in nature. The stacking interactions of substituted benzene heterodimers and substituted benzene-natural nucleobase heterodimers are examined. Both electron-donating and withdrawing groups are studied by varying their type, number and location around the benzene ring. The studies are done by carrying out systematic scans of the potential energy surface at the MP2/6-31G*(0.25) level of theory. Charge transfer interactions and extent of charge separation in the monomer are found to be dominant when the difference in ESP between the monomers is large and small, respectively. Dipole-dipole interactions are also found to affect stacking interactions. The results from MP2/6-31G*(0.25) are checked against those at the CCSD(T)/CBS limit for select cases and are found to be within 81- 110%.
xii, 166 leaves : ill. ; 29 cm
Physical organic chemistry , Benzene , Dimers , Molecule-molecule collisions , Chemical kinetics , Dissertations, Academic