Polymerization of 2‐Substituted 2‐Oxazolines Induced by Photocationic Initiators

2‐Ethyl‐2‐oxazoline (EOZO) was polymerized using two different photocationic initiators: a combination of bis{(4‐diphenylsulfonium)phenyl}sulfide bis{hexafluoroantimonate} and (4‐phenyl sulfide)phenyl diphenylsulfonium hexafluoroantimonate (Cyracure UVI® 6974) and (η⁵‐2,4‐cyclopentadien‐1‐yl)‐η⁶‐(1‐methylethyl)benzene]iron hexafluorophosphate (Irgacure® 261). The experimental data is consistent with the premise that in the presence of Cyracure UVI® 6974 the initiation proceeds via a Brønstedt acid. In the second case the generation of oxazolinium growing species is intermediated by a complex derived from the initial ferrocenium salt.