Copper ligand and anion effects: controlling the kinetics of the photoinitiated copper(i) catalyzed azide—alkyne cycloaddition polymerization. Issue 38 (3rd September 2018)

• Record Type: Journal Article
• Authors: El-Zaatari, Bassil M.; Cole, Shea M.; Bischoff, Derek J.; Kloxin, Christopher J.
• Is Part Of: Polymer chemistry. Volume 9:Issue 38(2018)
• Page Start: 4772
• Page End: 4780
• Publication Date: 2018-09-03
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/c8py01004h
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : The kinetic performance of amine-based ligands and counter anions on the copper(ii ) catalyst in photoinduced-CuAAC reactions is explored. Abstract : The kinetics of photoinduced copper(i ) catalyzed azide–alkyne cycloaddition (CuAAC) polymerizations were assessed as a function of copper(ii ) amine-based ligands. Copper(ii ) bromide ligated with 1, 1, 4, 7, 10, 10-hexamethylenetetramine (HMTETA) exhibited the fastest kinetics in both Norrish type(I) and type(II) photoinitiating systems. A characteristic induction period is observed with these polymerizations and is manipulated by adding an external tertiary amine in Norrish Type(II) photoinitiating systems or by changing the anion of the copper(ii ) salt. Halides, specifically bromide and chloride, exhibit the fastest kinetics with the smallest induction period in comparison with organic anions, such as bistriflimide and triflate. The temporal control of the photo-CuAAC polymerization is affected by pre-ligation of the copper catalyst, by the presence of certain anions such as acetate, and by specific ligands such as tetramethylethylenediamine (TMEDA).