To better understand the stereochemistry of poly (bicyclobutane-1-carbonitrile) (PBBC), 13C NMR studies were performed for a series of 3-substituted cyclobutanes. Of particular interest were the syntheses and NMR assignments for the two dimers (cis-and irans-3-(l-cyanocyclobutyl)cyclobutane-l-carbonitrile) and the four trimers. In all of the molecules studied, substituents at C3, which were cis to the nitrile, led to 13C NMR shifts of the nitrile that were 1-1.5 ppm to high field of those for the trans isomer; therefore the nitrile chemical shift is a very useful probe of cis/trans stereochemistry in cyclobutanecarbonitriles. Using data for cyclobutanecarbonitrile and the two dimers, we obtained additivity relationships; the calculated 13C resonances
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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.