DFT study on the interactions between Au(n) (n = 2...4) and adenine
Gang Lv1, Fadong Wei, Qingning Li
1State Key Lab of Bioelectronics (Chien-Shiung WU Laboratory), Southeast University, Nanjing, Si Pai Lou 2210096, PR China.
Journal of Nanoscience and Nanotechnology
|April 1, 2010
Summary
Gold clusters (Au(n)) bind to adenine, with strongest interactions at the N3 position. This study used density functional theory (DFT) to analyze the electronic structure and bonding in these complexes.
Area of Science:
- Computational Chemistry
- Materials Science
- Biochemistry
Background:
- Adenine is a fundamental component of nucleic acids and plays a crucial role in biological systems.
- Gold clusters are of interest due to their unique electronic and catalytic properties.
- Understanding the interaction between gold clusters and biomolecules like adenine is important for developing new nanomaterials and drug delivery systems.
Purpose of the Study:
- To investigate the binding mechanisms and structural properties of neutral gold clusters (Au(n), n=2-4) interacting with adenine.
- To determine the preferred binding sites and interaction energies between gold clusters and adenine.
- To analyze the charge transfer dynamics and the nature of stabilizing bonds in the formed complexes.
Main Methods:
- Density Functional Theory (DFT) calculations were employed to optimize the geometries of adenine-gold cluster complexes.
- The B3LYP functional with the 6-31G+(d, p) basis set for adenine and the SDD ECP for gold atoms were utilized.
- Natural Bond Orbital (NBO) analysis was performed to study charge distribution and stabilization energies.
Main Results:
- Optimized structures reveal stabilization through direct Au-N bonds and weaker non-conventional Au...H-N hydrogen bonds.
- Calculated interaction energies indicate that gold clusters bind most strongly to the N3 atom of adenine, with weaker binding observed at N6.
- NBO analysis shows charge transfer from adenine's nitrogen lone pair to gold's antibonding orbitals (n* and sigma*).
Conclusions:
- The Au-N anchoring bond is a primary contributor to the stability of adenine-gold cluster complexes.
- The binding strength of gold clusters to adenine is site-dependent, favoring N3 over N6.
- Computational DFT studies provide valuable insights into the molecular interactions relevant for designing gold-based nanostructures for biological applications.
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