Importance of the Position of the Chromophore Group on the Dissociation Process of Light Sensitive Alkoxyamines

Abstract

New photosensitive alkoxyamines have been designed using molecular orbital calculations to improve the selective CO versus NO cleavage. The targeted light-sensitive alkoxyamine is synthesized in one step and its reactivity under UV has been investigated using both ESR and LFP. The ability of this alkoxyamine to control the photopolymerization of n-butyl acrylate is evidenced through a process called nitroxide-mediated photopolymerization NMP(2) . The selected alkoxyamine is finally used to prepare covalently bonded multilayered micropatterns. This original application highlights the high potential of this technique for some specific applications that require spatial control.

Photodissociation of TEMPO-modified peptides: new approaches to radical-directed dissociation of biomolecules

“…The results from photodissociation of model systems suggests that the proximity of additional chromophores improves the efficiency of photodissociation and is consistent with prior observations in both polymers [68][69][70][71] and peptides. 72,73 Although the peptides investigated here incorporate aromatic residues, different peptide structures elicit only minor changes in the photodissociation profile.…”

Studies on Photoinduced ATRP in the Presence of Photoinitiator

“…[6][7][8][9][10][11] Several attempts were also made to covalently attach different chromphoric groups to the nitroxides moiety for NMRP process. [11][12][13][14][15] A thiocarbonylthio compound, known as a classical RAFT agent, is a photosensitive molecule that readily undergoes reversible b-cleavage at the carbon sulfur bond and thus yields some control over the radical polymerization process under UV irradiation. [16][17][18][19][20][21] Some studies have also focused on UV-induced ATRP and the effect of UV-Vis radiation on the controlled nature of the polymerization process.…”

Nitroxide Mediated Photopolymerization: A Versatile Tool for the Fabrication of Complex Multilayer Polyfunctional Copolymer Nanostructures

“…Photosensitive alkoxyamines have been recently introduced to induce living radical polymerization mediated by UV irradiation (nitroxide‐mediated photopolymerization (NMP2)) . We intend in this paper to show that this system can be successfully used to produce functional micro and nanopatterns with complex structures.…”

“…The details for the synthesis of the alkoxyamine (AA) are given in SI‐1. Modification from previous work of the molecular structure is proposed to first increase the inherent stability of the released nitroxide (iso‐propyl instead of methyl moiety) . Moreover using AA, we expected to limit side reactions that could occur due to the presence of the benzophenone moiety that was present on the initiating alkyl group (styryl instead of 4‐benzoyl styryl moiety).…”

“…Modification from previous work of the molecular structure is proposed to first increase the inherent stability of the released nitroxide (iso‐propyl instead of methyl moiety) . Moreover using AA, we expected to limit side reactions that could occur due to the presence of the benzophenone moiety that was present on the initiating alkyl group (styryl instead of 4‐benzoyl styryl moiety). In particular, with AA the chromophore group is only located on the nitroxide moiety to insure a reversible cleavage of the macroalkoxyamine during photopolymerization, as shown in Figure b.…”