Related Experiment Video
Updated: May 3, 2026

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores
Published on: August 19, 2013
Naked-eye detection of C1-C4 alcohols based on ground-state intramolecular proton transfer
Zhanxian Li1, Xingjiang Liu, Wanying Zhao
1The College of Chemistry and Molecular Engineering, Zhengzhou University , Zhengzhou 450001, China.
Abstract:
Previous reports of fluorescent sensors for alcohols based on charge-transfer character of their excited state are based on mono-, di-, and tetra-phosphonate cavitands, which are capable of selecting analytes through shape/size selection and various specific H-bonding, CH-π, and cation-dipole interactions. To contrast, color changes based on absorption properties of the ground state are more suitable for direct observation with the naked eye. Three sensitive and selective colorimetric sensors for C1-C4 alcohols have been developed on the basis of alcohol-mediated ground-state intramolecular proton transfer. Reverse proton transfer induced by water achieves a fully reversible reaction. In addition, the solvent color indicates alcohol concentration.
Related Concept Videos
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
¹H NMR of Labile Protons: Temporal Resolution
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the...
NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones
IR and UV–Vis Spectroscopy of Carboxylic Acids
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
Mass Spectrometry: Alcohol Fragmentation
IR Frequency Region: Alkene and Carbonyl Stretching
Stretching frequencies are affected by several factors, such as resonance, inductive effects, ring strain, dipole moment, and hydrogen bonding. Consequently, the stretching frequency of the carbonyl double bond...

