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Polarizability effects and dispersion interactions in alkene-Br2 pi-complexes
Cinzia Chiappe1, Heiner Detert, Dieter Lenoir
1Dipartimento di Chimica Bioorganica e Biofarmacia, Università di Pisa, I-56126 Pisa, Italy. cinziac@farm.unipi.it
Journal of the American Chemical Society
|March 6, 2003
Summary
Weakly bound molecular complexes are crucial in science. This study found a direct link between alkene polarizability and the stability of bromine pi-complexes, proposing a new predictive equation.
Area of Science:
- Molecular interactions
- Chemical physics
- Supramolecular chemistry
Background:
- Weakly bound molecular complexes are fundamental across chemistry, physics, and biological sciences.
- Understanding these interactions is key to predicting chemical reactivity and material properties.
Purpose of the Study:
- To quantitatively investigate the pre-equilibrium pi-complexes formed between various alkenes and bromine.
- To establish a quantitative relationship between the stability of these complexes and olefin properties.
Main Methods:
- Analysis of pre-equilibrium pi-complexes of alkenes with bromine.
- Quantitative examination of association constants (KF).
- Correlation analysis with olefin polarizability and ionization potential.
Main Results:
- A direct relationship was identified between the association constants (KF) of bromine-olefin pi-complexes and the polarizability of the olefins.
- The stability of these pi-complexes is influenced by both the donor ionization potential and the polarizability of the olefin.
Conclusions:
- The study proposes a new equation to predict the stability of Br2-olefin pi-complexes, incorporating both polarizability and ionization potential.
- This provides a more accurate method for understanding and predicting the behavior of these important molecular complexes.
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