Probing Benzoxazine Dimer Formation Using Methyl-Blocked Derivatives as Mechanistic Probes
Abstract
The early-stage dimer formation of 1,3-benzoxazine (PH-a) was investigated as a diagnostic system for understanding the ring-opening polymerization (ROP) mechanism using a coupled FAIMS-IRMPD-MS/MS platform. High-field asymmetric waveform ion mobility spectrometry (FAIMS) resolved the protonated PH-a dimer into three distinct populations. A series of methyl-blocked benzoxazine derivatives was used to systematically eliminate individual reactive sites and assign each FAIMS population to a specific reaction route via tandem MS fragmentation patterns and IRMPD action spectroscopy, supported by theoretical vibrational spectra obtained by DFT calculations. Four dimer formation pathways were confirmed: phenolic aromatic substitution at the ortho and para positions, and arylamine aromatic substitution at the ortho and para positions of the aniline ring. Phenoxy- and nitrogen-mediated attack routes were not observed. Each pathway yields dimers in either a closed-ring (CRB) or open-ring (ROP) form, a structural duality with direct implications for the crosslinking topology and network heterogeneity of the resulting polybenzoxazine.
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BibTeX
@misc{gomes2026probing,
title = {{Probing Benzoxazine Dimer Formation Using Methyl-Blocked Derivatives as Mechanistic Probes}},
author = {Rayan C. Gomes and Francisco W. M. Ribeiro and Thiago C. Correra},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010146/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010146/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Probing Benzoxazine Dimer Formation Using Methyl-Blocked Derivatives as Mechanistic Probes
AU - Rayan C. Gomes
AU - Francisco W. M. Ribeiro
AU - Thiago C. Correra
PY - 2026
DA - 2026/10/09
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010146/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010146/v1
AB - The early-stage dimer formation of 1,3-benzoxazine (PH-a) was investigated as a diagnostic system for understanding the ring-opening polymerization (ROP) mechanism using a coupled FAIMS-IRMPD-MS/MS platform. High-field asymmetric waveform ion mobility spectrometry (FAIMS) resolved the protonated PH-a dimer into three distinct populations. A series of methyl-blocked benzoxazine derivatives was used to systematically eliminate individual reactive sites and assign each FAIMS population to a specific reaction route via tandem MS fragmentation patterns and IRMPD action spectroscopy, supported by theoretical vibrational spectra obtained by DFT calculations. Four dimer formation pathways were confirmed: phenolic aromatic substitution at the ortho and para positions, and arylamine aromatic substitution at the ortho and para positions of the aniline ring. Phenoxy- and nitrogen-mediated attack routes were not observed. Each pathway yields dimers in either a closed-ring (CRB) or open-ring (ROP) form, a structural duality with direct implications for the crosslinking topology and network heterogeneity of the resulting polybenzoxazine.
ER -