Control over the Hydrogen-Bond Docking Site in Anisole by Ring Methylation
Hannes C Gottschalk1, Jonas Altnöder1, Matthias Heger1
1Institut für Physikalische Chemie, Georg-August-Universität Göttingen, Tammannstraße 6, 37077, Göttingen, Deutschland.
Angewandte Chemie (International Ed. in English)
|December 24, 2015
Summary
Researchers studied how methanol binds to anisole using hydrogen bonds or pi contacts. Methylation and tert-butyl groups altered this balance, allowing accurate testing of quantum chemistry methods for predicting molecular interactions.
Area of Science:
- Supramolecular chemistry
- Physical chemistry
- Computational chemistry
Background:
- Methanol can dock to anisole through OH⋅⋅⋅O hydrogen bonds or OH⋅⋅⋅π contacts.
- The balance between these binding modes is sensitive to molecular structure.
Purpose of the Study:
- To investigate the influence of methylation and tert-butyl substituents on methanol-anisole complexation.
- To evaluate the accuracy of quantum-chemical methods in predicting relative binding energies.
Main Methods:
- Infrared spectroscopy in supersonic jets to probe molecular interactions.
- Quantum-chemical calculations (B3LYP-D3/aVTZ, M06-2X, CCSD(T)) to model binding energies.
Main Results:
- Structural modifications significantly altered the OH⋅⋅⋅O to OH⋅⋅⋅π binding ratio.
- B3LYP-D3/aVTZ and CCSD(T) methods accurately predicted relative energies.
- M06-2X systematically overestimated the stability of π-coordinated structures.
Conclusions:
- Quantum chemical methods can be rigorously tested using spectroscopic data from tunable supramolecular complexes.
- Understanding substituent effects is crucial for accurate prediction of non-covalent interactions.
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