AB Spin System: Analysis

Contents

This page contains:

1. a form to extract coupling constants and chemical shifts from observed frequencies,
2. and simulations using the solution.

For general information on the AB spin system, see this page: AB, General Information.

Input Section

Please enter the four frequencies (in Hz) of the peaks in descending order and the frequency SF of the reference compound (in MHz), as well as the desired total width of the simulated spectra in pixels (be reasonable ;-):

f1:	Hz	SF:	MHz
f2:	Hz	width:	pixel
f3:	Hz
f4:	Hz

 

Input Data
AB spectrum:	ν1 / Hz	ν2 / Hz	ν3 / Hz	ν4 / Hz
	2468.2	-4568.3	-14406.3	-21444.6
JAB (err):	7037.40 (0.90) Hz

Solution:

f0:	-9487.75 Hz
D:	15338.00 Hz
JAB:	7037.40 Hz
D/JAB:	2.18
2C:	16875.40 Hz
(2C-D)/2:	768.70 Hz / 4.12 ppm
νA:	-1818.75 Hz	δA:	-9.7519 ppm
νB:	-17156.75 Hz	δB:	-91.9925 ppm

Simulation of AB

 (Interested in the image? Here is information on the SVG graphics: SVG)
 

ν1 =	2468.65 Hz	I1 =	0.5830	plot limits:
ν2 =	-4568.75 Hz	I2 =	1.4170	high frequency:	4859.93
ν3 =	-14406.75 Hz	I3 =	1.4170	low frequency:	-23835.43
ν4 =	-21444.15 Hz	I4 =	0.5830

 

References

1. Günther, H. NMR-Spektroskopie, Eine Einführung. Georg Thieme Verlag, Stuttgart, 1973.
2. Garbisch, E. W., Jr., J. Chem. Educ. 1968, 45, 311-321, DOI: 10.1021/ed045p311.
3. Dischler, B. Angew. Chem. 1966, 78, 653-663, DOI: 10.1002/ange.19660781302;
   Angew. Chem. Int. Ed. Engl. 1966, 5, 623-633, DOI: 10.1002/anie.196606231.