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Proton affinity correlations between hydrogen and dihydrogen bond acceptors.
Prashant Chandra Singh1, G Naresh Patwari
1Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
The Journal of Physical Chemistry. A
|April 4, 2007
Summary
This study explores hydrogen and dihydrogen bonds using computational chemistry. Dihydrogen bonds are found to be 16-20% weaker than hydrogen bonds under similar conditions.
Area of Science:
- Computational Chemistry
- Molecular Interactions
- Quantum Chemistry
Background:
- Hydrogen bonds are crucial in chemistry and biology.
- Understanding dihydrogen bonds is essential for a complete picture of intermolecular forces.
- Previous research has explored various hydrogen-bonded systems.
Purpose of the Study:
- To investigate hydrogen- and dihydrogen-bonded complexes computationally.
- To correlate X-H stretching frequency shifts with proton affinities.
- To develop a method for estimating dihydrogen bond acceptor proton affinities.
Main Methods:
- Utilized the MP2/6-311++G(d,p) level of theory for calculations.
- Investigated complexes with diverse hydrogen bond donors and acceptors.
- Performed linear correlation analysis between frequency shifts and proton affinities.
Main Results:
- Established a linear correlation between X-H stretching frequency lowering and proton affinities.
- Developed a scaling factor to estimate proton affinities for dihydrogen bond acceptors.
- Found that hydrogen bonds are 16-20% stronger than dihydrogen bonds.
Conclusions:
- The strength of hydrogen and dihydrogen bonds can be quantitatively compared.
- A reliable method for assessing dihydrogen bond strength was developed.
- This research provides insights into the relative strengths of different non-covalent interactions.
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