The document outlines the concept of coupling constants in NMR spectroscopy, detailing their significance in measuring spin-spin coupling between atoms. It describes three types of coupling: geminal, vicinal, and long-range coupling, along with their related equations and applications. Additionally, it discusses the relationship between chemical shift values and coupling constants, providing insights into their practical use in analyzing complex molecular structures.

1. COUPLING CONSTANT
G u i d e d B y
D r . V . S r i d h a r a n
A s s o c i a t e P r o f e s s o r ( H . O . D . )
P r e p a r e d B y
S h a k t i R a n j a n S a m a l
R o l l N o : - 2 4 4 1 6 1 6
Department Of Chemistry And Chemical Sciences
Central University Of Jammu, j&k

2. CONTENT
 INTRODUCTION
 TYPES
 Geminal Coupling
 Vicinal Coupling
 Long Range Coupling
 APPLICATION OF NMR SPECTROSCOPY

3. INTRODUCTION
 The distance between the peaks in given multiplet is a measure of
splitting effect known as coupling constant
 It is denoted by symbol J and expressed in Hz.
 Coupling constant are a measure of the effective ness of spin–spin
coupling and very useful in 1H NMR of complex structures.

4. J = Difference of chemical shift value in ppm
1 ppm = 60 Hz
1 ppm = 300 Hz

5. TYPES
There are three type of coupling constant
1. Geminal Coupling
2. Vicinal Coupling
3. Long Range Coupling

6. GEMINAL COUPLING

7. VICINAL COUPLING

8. Karplus Diagram
Karplus equation:
J= 8.5cos2- 0.28(0-900)
J= 9.5cos2- 0.28(900-1800)

9. Problems

10. LONG RANGE COUPLING

11. Range Of The Coupling Constant

12. APPLICATION OF NMR SPECTROSCOPY