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From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Photochemical Dehalogenation of Aryl Halides: Importance of Halogen Bonding
Ayda Elhage1, Paolo Costa1, Amrah Nasim1
1Department of Chemistry and Biomolecular Science, Centre for Advanced Materials Research (CAMaR) , University of Ottawa , 10 Marie Curie , Ottawa , ON K1N 6N5 , Canada.
Abstract:
Upon UVA irradiation, aryl halides can undergo dehalogenation in the presence of bases and methanol as a hydrogen donor. This catalyst-free photochemical dehalogenation is furnished through a facile radical chain reaction under mild conditions. The chain reaction follows UVA irradiation of the reaction mixture in a transition-metal-free environment. Mechanistic studies support a chain mechanism in which initiation involves absorption by a methoxide-bromoarene complex facilitated by halogen-bonding interactions. The methoxide-bromine interaction leads to a weakened Br-C bond that is prone to facile cleavage during the initiation and propagation steps.
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