Infrared intensities and charge mobility in hydrogen bonded complexes
Daria Galimberti1, Alberto Milani, Chiara Castiglioni
1Dipartimento di Chimica, Materiali e Ingegneria Chimica Giulio Natta, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
The Journal of Chemical Physics
|August 24, 2013
Summary
This study applies an analytical model to hydrogen-bonded dimers, revealing charge fluxes beyond directly bonded atoms. This explains infrared intensity enhancements in molecular vibrations.
Area of Science:
- Molecular Spectroscopy
- Quantum Chemistry
- Computational Chemistry
Background:
- Hydrogen bonding significantly alters molecular properties.
- Infrared (IR) spectroscopy is crucial for studying molecular vibrations.
- Understanding charge distribution changes is key to interpreting spectral shifts.
Purpose of the Study:
- To apply an analytical model to hydrogen-bonded planar dimers.
- To interpret the enhancement of IR intensity in X-H stretching bands upon aggregation.
- To investigate the role of charge fluxes in spectral behavior.
Main Methods:
- Utilizing an analytical model for charge mobility.
- Employing density functional theory (DFT) for atomic charges and polar tensors.
- Analyzing atomic charges and charge fluxes in hydrogen-bonded dimers.
Main Results:
- Charge fluxes, both principal and non-principal, are vital for spectral interpretation.
- Charge distribution modulation extends beyond atoms directly involved in hydrogen bonds.
- Correlations were established between IR intensities, interaction energies, and charge fluxes.
Conclusions:
- The analytical model successfully explains IR intensity enhancements in hydrogen-bonded systems.
- Charge flux analysis provides a deeper understanding of vibrational spectral behavior.
- The model's applicability to complex systems like cytosine-guanine is demonstrated.
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