Introduction

Nuclear Overhauser Effect Phenomenon was first predicted by Albert Overhauser in 1953. It was later experimentally observed by Solomon in 1955.

In this, the resonance line intensity changes caused by dipolar cross-relaxation from neighbouring spins with the perturbated energy populations¹. A spin excited nucleus may undergo spin relaxation via the transfer of its spin energy to that of an adjacent nucleus. The efficiency of this energy transfer is directly related to the distance between the two nuclei. The nuclear overhauser effect is though space phenomenon which takes advantage of this spin energy transfer. The nuclear overhauser effect can be used to demonstrate that two protons or two nuclei (or group of protons/nuclei) are in close proximity within the molecule, and is therefore of considerable value in the study of molecular geometry. It is a powerful technique for structural studies. Protons that are 6Ǻ apart can show an NOE. Knowing approximate distances between certain protons in a molecule can help to establish the conformation of a molecule. NOE information is commonly used in biochemical studies on the conformation of large proteins and nucleic acids².