Introduction:
The Nuclear magnetic resonance spectroscopy is a powerful method for the characterization of the exact structure of compounds. Here we illustrate the use of two dimensional NMR in the structure elucidation and other specialized application of NMR.
Two-Dimensional NMR Spectroscopy:
1H-1H correlation or COSY experiments let protons to be coupled to one other. The figure below illustrates the correlated spectroscopy spectrum of aspirin. The diagonal provides the correlation of the signals themselves that is, A with A, B with B and so on. On either side of the diagonal, similar information is presented; therefore only one diagonal is needed for spectral interpretation. From the spectra, it can be observe that A is coupled to C, B is coupled to C and D; and C is weakly coupled to D through long-range meta-coupling. COSY has simplified the interpretation of complex NMR spectra. There are a number of methods stemming from the fundamental two-dimensional method, which for illustration, allows correlation between the carbon atoms and protons linked to them and correlations of carbon atoms having protons one or two bonds eliminated from them, heteronuclear multiple bond correlation (HMBC).
Fig: 1H-1H-COSY Spectrum of Aspirin
Other Applications of Nuclear Magnetic Resonance Spectroscopy:
We are familiar with the use of NMR as a powerful method for the characterization of the exact structure of organic compounds by using 1H-NMR, 13C-NMR and COSY experiments. The other applications comprise:
1) Determination of the impurities comprises enantiomeric impurities without separation down to ca 10% level.
2) NMR can be employed as a rapid and specific quantitative method. For illustration, a drug can be rapidly quantified via measuring appropriate protons (mostly isolated methyl protons) against the intense singlet for the methyl groups in t-butanol. The amount of drug present can be computed by using the given formula for the methyl groups in t-butanol employed as an internal standard (int. std.)
Amount of drug = (Area signal for drug protons/Are signal for int.std. protons) x mass of int. std. added x (MW drug/MW int. std) x (No. of protons from int. std./No. of protons from drug)
The benefit of this process of quantization is that a pure external standard for the drug is not needed as the response is purely proportional to the number of protons present and this can be measured against the pure internal standard. Therefore, the purity of a substance can now be found out without a pure standard for it being available.
3) NMR has been developed lately, in conjunction by the chemometrics, as a tool for the diagnosis of disease. For such purposes it is often interfaced by HPLC. It has as well found broad application in the magnetic resonance imaging, a method that might be employed for imaging soft tissues by using NMR signal generated by the protons within the tissues. LC-NMR has as well found application in the drug metabolic studies.
Tutorsglobe: A way to secure high grade in your curriculum (Online Tutoring)
Expand your confidence, grow study skills and improve your grades.
Since 2009, Tutorsglobe has proactively helped millions of students to get better grades in school, college or university and score well in competitive tests with live, one-on-one online tutoring.
Using an advanced developed tutoring system providing little or no wait time, the students are connected on-demand with a tutor at www.tutorsglobe.com. Students work one-on-one, in real-time with a tutor, communicating and studying using a virtual whiteboard technology. Scientific and mathematical notation, symbols, geometric figures, graphing and freehand drawing can be rendered quickly and easily in the advanced whiteboard.
Free to know our price and packages for online Chemistry tutoring. Chat with us or submit request at [email protected]
tutorsglobe.com occurrence and principles of extraction of zinc assignment help-homework help by online first transition series tutors
tutorsglobe.com test for identification assignment help-homework help by online epidemiology tutors
Osmotic and Water Potentials tutorial all along with the key concepts of Osmotic Potential, Turgor pressure and wall pressure, Diffusion pressure deficit, Water potential, Kinds of plasmolysis, Factors affecting Imbibition
tutorsglobe.com commensalism assignment help-homework help by online positive interactions tutors
Magnetic Properties of Matter tutorial all along with the key concepts of Magnetic Dipoles, Magnetization and Susceptibility, Diamagnetism, Paramagnetism, Ferromagnetism and Antiferromagnetism
www.tutorsglobe.com offers theory of theory of unemployment and calculate unemployment rate, assignment help and homework help by economics tutor's help.
tutorsglobe.com arc method assignment help-homework help by online measurement of price elasticity of demand tutors
www.tutorsglobe.com offers piece wage system homework help, assignment help, case study, writing homework help, online tutoring assistance by accounting tutors.
tutorsglobe.com pancreas assignment help-homework help by online co-ordination systems tutors
Stop fiddling and avail our customized Engineering Mathematics Assignment Help to attain highest grades with 24x7 support of PhD tutors.
Preparation of Hexaamminecolbalt (III) Chloride tutorial all along with the key concepts of Preparation ofHexaamminecobalt, Preparation of Ethylenediamine and Concept of Limiting Reactant
tutorsglobe.com main axis elongated assignment help-homework help by online racemose inflorescence tutors
Relativity of Mass tutorial all along with the key concepts of Variation of Mass with Velocity, Momentum and Force in Relativistic Mechanics, glancing collision
Stellar Magnitudes tutorial all along with the key concepts of magnitude scale, Apparent Magnitude, Absolute Magnitude, Distance Modulus, Influence of Wavelength on Brightness, Brightness-Luminosity Relationship, Flux Photometry, Luminosity of Stars
Labour cost audit program - Proper use of labour and increase in productivity are at present receiving greater attention. Various Productivity Teams have emphasised great significance on higher productivity.
1938232
Questions Asked
3689
Tutors
1493863
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!