1H-1H couplings arise from influences on a proton’s magnetic field induced by the magnetic field of a neighbouring proton(s). As a proton experiences coupling from a neighbouring proton, so too is the coupling reciprocated to the neighbouring proton(s). By measuring the J-coupling for each splitting pattern, the proton connectivity information can be deduced.
By comparing the J-coupling for each splitting pattern in the 1H NMR below, roughly +/- 0.2 Hz, one can determine which multiplets pair up. Based on the pairing information, we can deduce that the proton is within proximity of its pair.
Coupled protons are:
Multiplets A and C = green line
Multiplets B and C = orange line
Multiplets D and C = purple line.
Multiplets E and C = red line.
Multiplets D and E = black line.
Excuse me, from this NMR spectrum, what is the structure or the molecules do they come from? Thank you very much.
Posted by: Arwika | September 07, 2016 at 06:32 AM
Hello Arwika,
Thank you for your interest in my blog. The compound is similar to the one posted here http://blog.acdlabs.com/elucidation/2008/10/anisochronous-p.html . When dealing with unknown compounds, it is best to look at NMR and MS data. This also includes database searches such as outlined here http://pubs.rsc.org/is/content/articlelanding/2015/ob/c5ob01713k#!divAbstract .
Regards,
Arvin Moser, M.Sc.
Posted by: Arvin | September 07, 2016 at 09:41 AM