Reaction of octafluorocyclotetraphosphonitrile with methyllithium

Article abstract of DOI:10.1021/ic50120a015

Octafluorocyclotetraphosphonitrile reacts with methyllithium to give methyl, dimethyl, trimethyl, and tetramethyl derivatives and finally octamethylcyclotetraphosphonitrile. All five dimethyl derivatives were found, and two of them (geminal and trans-antipodal) were characterized completely by ³¹P, ¹H, and ¹⁹F nmr spectroscopy. Trimethylation was exclusively geminal; of the five trimethyl derivatives, the geminal-vicinal and geminal-antipodal compounds have been characterized in detail with the help of their decoupled ¹H and ¹⁹F nmr spectra. The single tetramethyl derivative isolated exemplifies a novel orientation pattern in phosphonitrilic chemistry, viz., geminal substitution followed by reaction at an antipodal site. The orientation pattern and the bond length inequalities observed in the structure of gem-dimethylhexafluorocyclotetraphosphonitrile are interpreted in terms of perturbation theory applied to a delocalized π-electron system.