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Two‐in‐One: λ‐Orthogonal Photochemistry on a Radical Photoinitiating System
Author(s) -
Hurrle Silvana,
Lauer Andrea,
Gliemann Hartmut,
Mutlu Hatice,
Wöll Christof,
Goldmann Anja S.,
BarnerKowollik Christopher
Publication year - 2017
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201600598
Subject(s) - photoinitiator , alkyne , photopolymer , photochemistry , surface modification , ethylene glycol , materials science , polymer chemistry , moiety , polymerization , chemistry , monomer , polymer , organic chemistry , catalysis , composite material
An alkyne functional radical photoinitiator, 2‐(4‐(2‐hydroxy‐2‐methylpropanoyl)phenoxy)ethyl hex‐5‐ynoate, and evidence that both reactive moieties – the alkyne and the photoinitiator terminus – can be independently addressed with light of disparate wavelength (λ‐orthogonality) are introduced. The alkyne functionality is subjected to a visible light (420 nm) induced copper‐catalyzed Huisgen reaction, which is employed for the selective functionalization of the initiator with a poly(ethylene glycol) (PEG) chain. This reaction proceeds completely λ‐orthogonal in the presence of the UV‐reactive photoinitiating moiety. Conversely, it is demonstrated that the alkyne functionality of the photoinitiator is quantitatively orthogonal to UV irradiation emitted by the pulsing action of an excimer laser (351 nm, pulsed‐laser polymerization, PLP) and the generated radical species. In turn, the PEGylated initiator can readily be employed as a macrophotoinitiator during PLP. The introduced λ‐orthogonally addressable dual functional initiator can be used in a wide range of applications, including surface lithography and post‐synthetic modification of photocured materials.