Study of Nuclear magnetic resonance by Qaiser Siddique, Vallo Zinin and Razib Hossain.
Basics:
Nuclear magnetic resonance builds on the physics concepts of resonance and nuclear spin(angular momentum of elementary particles of an atom). Protons, electrons, atomic nuclei, and other elementary particles have an intrinsic spin as if they were spinning on their axes.When atomic nuclei, or other charged particles, spin they become like a magnetic dipole (like a bar magnet).A nucleus, or elementary particle, possessing spin will wobble or precess when they are placed in a magnetic field. A nucleus in a magnetic field precesses at a frequency, called the Larmor frequency, which is proportional to the magnetic field.
When an atom is in a constant magnetic field, it nucleus precesses at the Larmor frequency. If in addition to the constant magnetic field, there is also a weaker perpendicular magnetic field that varies at the same frequency as the Larmor frequency for the nucleus, then the nucleus resonates. The phenomenon is called Nuclear Magnetic Resonance (NMR).
Analogy:
This nuclear magnetic resonance (NMR) causes the spin of the nucleus to flip.The analogy for Earth spinning on its axis would be if Earth flipped so that the north and south poles interchanged and Earth were suddenly spinning in the opposite direction. Just as it would take considerable energy to flip Earth's spinning motion, the nucleus absorbs and emits energy as it flips its spin. With the correct electronic equipment physicists can measure the spectrum of absorbed and emitted energy.
NMR Spectroscopy
One common application of nuclear magnetic resonance is NMR spectroscopy. Physicists and chemists study the NMR spectrum produced by a sample of material and deduce the properties of the nuclei in the sample. This tells them what elements are in the sample.
MRI Medical Imaging
A better known application of nuclear magnetic resonance is magnetic resonance imaging (MRI). MRI uses the nuclear magnetic resonance effect of the hydrogen atoms in the human body. Computer analysis of the resonance data produces an internal image of the patients body. MRI produces diagnostic medical imaging that neither harms the body in any way nor requires surgeons to cut open or enter the body.
Nuclear magnetic resonance is an interesting phenomenon taking place in the nuclei of atoms that also has very important applications.
Spectroscopy
Spectroscopy is the study of the interaction of electromagnetic radiation with matter. Nuclear magnetic resonance spectroscopy is the use of the NMR phenomenon to study physical, chemical, and biological properties of matter. As a consequence, NMR spectroscopy finds applications in several areas of science. NMR spectroscopy is routinely used by chemists to study chemical structure using simple one-dimensional techniques. Two-dimensional techniques are used to determine the structure of more complicated molecules. These techniques are replacing x-ray crystallography for the determination of protein structure. Time domain NMR spectroscopic techniques are used to probe molecular dynamics in solutions. Solid state NMR spectroscopy is used to determine the molecular structure of solids. Other scientists have developed NMR methods of measuring diffusion coefficients.
The versatility of NMR makes it pervasive in the sciences. Scientists and students are discovering that knowledge of the science and technology of NMR is essential for applying, as well as developing, new applications for it. Unfortunately many of the dynamic concepts of NMR spectroscopy are difficult for the novice to understand when static diagrams in hard copy texts are used. The chapters in this hypertext book on NMR are designed in such a way to incorporate both static and dynamic figures with hypertext. This book presents a comprehensive picture of the basic principles necessary to begin using NMR spectroscopy, and it will provide you with an understanding of the principles of NMR from the microscopic, macroscopic, and system perspectives.