Cyclic oligomers of caprolactam were isolated from a multilayered polyolefin plastic film containing a nylon-6 layer and subsequently characterized. Nylon-6 was extracted with aqueous solutions and the levels of the oligomers were measured in the resulting extracts. Oligomers up to n ϭ 5 were present at high and comparable levels in all the nylon-6 extracts. The levels of the oligomers dropped off rapidly with increased compound size after n ϭ 5, with the heptamer being barely observable in the extract chromatograms. The effect of extracting solution pH on the compound's concentration in the extract was small, except for the monomer, whose accumulation was significantly decreased at low pH.
The first examples of chelate assisted insertion of a transition metal centre into a C-F bond of mono-and di-fluoro substituted aromatic rings resulting in chelate stabilized aryl fluoride oxidative addition complexes are reported.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.