Related Experiment Video
Updated: Jul 10, 2026

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Intramolecular hydrogen bonding (proton transfer) of 1-phenyl-1,3-butanedione
Hideyo Matsuzawa1, Takashi Nakagaki, Makio Iwahashi
1School of Science, Kitasato University, Kitasato, Sagamihara, Japan. matsu@sci.kitasato-u.ac.jp
Abstract:
Through the (1)H and (13)C NMR measurements for the symmetrical beta-diketones such as 2,4-pentanedione and 1,3-diphenyl-1,3-propanedione and unsymmetrical one such as 1-phenyl-1,3-butanedione at various concentrations and temperatures, we confirmed that 1-phenyl-1,3-butanedione in CDCl(3) exists as monomers in its relatively low concentration. In addition, the 1-phenyl-1,3-butanedione in CDCl(3) exists not as a keto-form but as two kinds of cis-enol forms. The proton transfer between the two kinds of cis-enols for 1-phenyl-1,3-butanedione was discussed thermodynamically; it is concluded that the OH proton of enol of 1-phenyl-1,3-butanedione is considerably located near the oxygen atom attached to the carbon atom linking to a phenyl group.
Related Concept Videos
π Molecular Orbitals of 1,3-Butadiene
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control
Stability of Conjugated Dienes
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
Hydrolysis of Chlorobenzene to Phenol: Dow Process

