Friday, January 11, 2008
13C Showing J Coupling to Both 31P and 14N
Despite my efforts, some novice users still believe that all 13C resonances are sharp singlets. This is indeed the case in proton decoupled 13C spectra where there is no additional heteronuclear coupling, exchange or fast relaxation. In the BLOG entries for December 11, 2007 and October 9, 2007 , I showed 13C NMR spectra where the carbon was coupled to 14N and 19F, respectively. The spectrum below is a 13C spectrum where 13C couples with 31P and 14N. The yellow region of the full spectrum is expanded in the inset. Carbon 2 is particularly interesting as it shows coupling to both 31P and 14 N.