Related Experiment Video
Updated: Aug 19, 2026

Synthesis of High Purity Nonsymmetric Dialkylphosphinic Acid Extractants
Published on: October 19, 2017
Why does pivalaldehyde (trimethylacetaldehyde) unexpectedly seem more basic than 1-adamantanecarbaldehyde in the gas
Esther Quintanilla1, Juan Z Dávalos, José-Luis M Abboud
1Instituto de Química Física Rocasolano, CSIC, C/Serrano 119, 28006 Madrid, Spain.
Abstract:
Fourier transform ion cyclotron resonance spectroscopy (FT ICR) techniques, including collision-induced dissociation (CID) methodology, were applied to the study of the gas-phase protonation of pivalaldehyde (1) and 1-adamantanecarbaldehyde (2). A new synthetic method for 2 was developed. The experiments, together with a thorough computational study involving ab initio and density functional theory (DFT) calculations of high level, conclusively show that upon monoprotonation in the gas phase, compound 1 yields monoprotonated methyl isopropyl ketone 3. The mechanism of this gas-phase acid-catalyzed isomerization is different from that reported by Olah and Suryah Prakash for the reaction in solution. In the latter case, isomerization takes place through the diprotonation of 1.
Related Concept Videos
Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
Spectroscopy of Carboxylic Acid Derivatives
In the...
IUPAC Nomenclature of Aldehydes
Acidity and Basicity of Carboxylic Acid Derivatives
The relative acidic strength of the derivatives can be explained based on the extent of resonance stabilization of the conjugate base. The...
Structures of Aldehydes and Ketones
In aldehydes (Figures 1a and 1b), the carbonyl...
Acidity of Carboxylic Acids

