relation: http://d-scholarship-dev.library.pitt.edu/17777/
title: N-heterocyclic carbenes-borane complexes: A new class of initiators for radical photopolymerization
creator: Tehfe, MA
creator: Brahmi, MM
creator: Fouassier, JP
creator: Curran, DP
creator: Malacria, M
creator: Fensterbank, L
creator: Lacôte, E
creator: Lalevée, J
description: Newly discovered N-heterocyclic carbene-boryl radicals (NHC-BH 2•) derived from readily available N-heterocyclic carbene-boranes are found to be efficient initiators for acrylate photopolymerization. Laser flash photolysis (LFP) experiments were used to generate three carbene-boryl radicals, which were characterized by their transient absorption spectra with the aid of DFT calculations. Rate constants were measured for the generation of the carbene-boryl radicals by hydrogen abstraction with tert--butoxyl radical, a ketophosphonyl radical, and triplet benzophenone. Rate constants were also measured for the reactions of the carbene-boryl radicals with oxygen, three alkenes, two alkyl chlorides, and diphenyliodonium hexafluorophosphate. The observed trends were interpreted with the aid of measured oxidation potentials of the carbene-boranes and calculated ionization potentials of the carbene-boryls. N-Heterocyclic carbeneboranes show excellent potential as both photopolymerization co-initiators and mediators of small molecule radical reactions, and these results will help guide further development in both fields. © 2010 American Chemical Society.
date: 2010-03-09
type: Article
type: PeerReviewed
format: text/plain
language: en
rights: attached
identifier: http://d-scholarship-dev.library.pitt.edu/17777/1/licence.txt
identifier:   Tehfe, MA and Brahmi, MM and Fouassier, JP and Curran, DP and Malacria, M and Fensterbank, L and Lacôte, E and Lalevée, J  (2010) N-heterocyclic carbenes-borane complexes: A new class of initiators for radical photopolymerization.  Macromolecules, 43 (5).  2261 - 2267.  ISSN 0024-9297     
relation: 10.1021/ma902492q