Related Experiment Video
Updated: Jan 15, 2026

Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
Published on: May 26, 2014
Direct observation and identification of resonance-stabilized radicals in a sooting flame
X Mercier1, J Bourgalais2, A Faccinetto3
1Université Lille, CNRS, UMR 8522 - PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, Lille, France. xavier.mercier@univ-lille.fr.
Abstract:
Understanding the molecular mechanisms governing soot inception is critical for developing accurate models of particulate formation in combustion systems. Polycyclic aromatic hydrocarbons (PAHs) are well established as key precursors/intermediates that participate to soot formation, but the growth reactions towards the particulate phase are still the subject of active debate. Among the proposed chemical mechanisms, aromatic resonance-stabilized radicals (RSRs) offer a promising alternative pathway, but their in situ detection in flames has proven challenging, limiting further mechanistic insight. Here, we report the direct observation and identification of several polycyclic aromatic RSRs, using a combination of synchrotron-based mass-selected vacuum ultraviolet photoelectron spectroscopy and quantum chemical calculations. The existence of both delocalized and localized π-radicals and their specific implication on the different stages of soot formation, via radical-driven PAH reaction mechanisms, is discussed in the context of combustion chemistry.
More Related Videos
07:24Combustion Chemistry of Fuels: Quantitative Speciation Data Obtained from an Atmospheric High-temperature Flow Reactor with Coupled Molecular-beam Mass Spectrometer
Published on: February 19, 2018
09:23A Protocol for Detecting and Scavenging Gas-phase Free Radicals in Mainstream Cigarette Smoke
Published on: January 2, 2012
Related Concept Videos
Flame Photometry: Overview
Radical Reactivity: Steric Effects
Along with electronic...
Flame Photometry: Lab
Radical Reactivity: Overview
Radical Reactivity: Nucleophilic Radicals
Radical Formation: Elimination