Understanding benzyl alcohol aggregation by chiral modification: the pairing step.
1Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, 37077 Goettingen, Germany. msuhm@gwdg.de.
Physical Chemistry Chemical Physics : PCCP
|November 10, 2020
Summary
Benzyl alcohol dimers exhibit specific chiral arrangements in isolation. This study reveals homochiral and heterochiral dimer structures, providing insights into molecular chirality and bonding.
Area of Science:
- Physical Chemistry
- Spectroscopy
- Computational Chemistry
Background:
- Understanding molecular conformation and chirality is crucial in chemistry.
- Benzyl alcohol (phenylmethanol) is a transiently chiral molecule whose dimer behavior requires clarification.
- Supersonic jet expansions provide isolated conditions for studying molecular interactions.
Purpose of the Study:
- To elucidate the conformational preferences and chirality of benzyl alcohol dimers.
- To compare with permanently chiral 1-phenylethanol to understand chirality induction.
- To evaluate computational methods for predicting molecular structures and energies.
Main Methods:
- Combined linear infrared (IR) and Raman spectroscopy in supersonic slit jet expansions.
- Experimental investigation using analogies with 1-phenylethanol.
- Computational analysis of conformational energy landscapes.
Main Results:
- The lowest energy benzyl alcohol dimer is homochiral with cooperative OHOHπ-bonding.
- A higher energy heterochiral dimer was identified as a minor component.
- A metastable heterochiral OHπ/OHπ dimer structure was observed, trapped by a symmetry barrier.
Conclusions:
- Benzyl alcohol dimers preferentially form homochiral structures under isolated conditions.
- Experimental and computational methods successfully characterized dimer conformations and chirality.
- The study provides benchmarks for assessing density functional theory methods in predicting chiral interactions.
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