Related Experiment Video
Updated: Apr 14, 2026

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown
Published on: February 14, 2014
Negative Hyperconjugation versus Electronegativity: Vibrational Spectra of Free Fluorinated Alkoxide Ions in the Gas
Jos Oomens1,2, Giel Berden1, Thomas Hellman Morton3
1Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525ED Nijmegen (The Netherlands).
Abstract:
CO stretching frequencies of free, gaseous, fluorinated alkoxide ions shift substantially to the blue, relative to those of corresponding alcohols complexed with ammonia. Free α-fluorinated ions, pentafluoroethoxide and heptafluoroisopropoxide anions, display further blue shifts relative to cases with only β-fluorination, providing experimental evidence for fluorine negative hyperconjugation. DFT analysis with the atoms in molecules (AIM) method confirms an increase in CO bond order for the α-fluorinated ions, demonstrating an increase in carbonyl character for the free ions.
More Related Videos
11:38In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework
Published on: February 1, 2020
05:48Analysis of Volatile and Oxidation Sensitive Compounds Using a Cold Inlet System and Electron Impact Mass Spectrometry
Published on: September 5, 2014
Related Concept Videos
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
UV–Vis Spectroscopy: Molecular Electronic Transitions
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...
Mass Spectrometry: Alkyl Halide Fragmentation
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Atomic Spectroscopy: Absorption, Emission, and Fluorescence