The alkyl oxonium ion, which is a protonated alcohol, has long been proposed as a key
reaction intermediate in alcohol dehydration. Nonetheless, the dynamics and structure of
this simple but important intermediate species have not been adequately examined due to
the transient nature of the oxonium ion. Here, we devised a model system for the key step in
the alcohol dehydration reaction, in which a photoacid transfers a proton to alcohols of
different basicity in the acetonitrile solvent. Using time-resolved spectroscopy and …

… Here, devised is a key step in the alcohol dehydration reaction, acid catalysis, to transfer
a proton to alcohols. Using time-resolved spectroscopy and computation, the hydrogen-bonded
clustering of at least two alcohol molecules is found to be critical for enhanced basicity. This
finding addresses the cooperative role of the organic protic compounds in nonaqueous acid–base
reactions. …