Chapter 14.22, Problem 45P

Interpretation Introduction

Interpretation:

To identify the pairs of coupled protons in the compound from the given COSY spectrum.

Concept introduction:

A two-dimensional spectrum is used to analyse the complex structures such as proteins and carbohydrates instead of the simple one-dimensional spectrum.  The most common two-dimensional spectrum used is COSY.

COSY stands for homonuclear ${}^1{\text{H-}}^1\text{H}$ shift COrrelated SpectroscopY and it gives information about the coupled proton.

To analyse a COSY spectrum first a diagonal line is drawn passing through the dots such that it bisects the spectrum. Each dot represents a separate signal.  The dots that do not lie on the diagonal line are called the cross peak.  Cross-peak shows the pair of the coupled proton.