Nuclear
Magnetic Resonance (NMR) spectroscopy is one of the most powerful analytical
tools used for various purposes in scientific research. Chemists are the
largest group of users of NMR, employed mainly for structure elucidation of
unknown compounds. Several different types of techniques (each differing from
the other by the pulse sequence involved) are used in NMR, affording different
information about the structure of a compound. NMR has some of the most
comprehensive terminologies used for its techniques. The acronyms used are even
more interesting.
Following
is a list of the acronyms of 10 different techniques used in NMR. Rest assured
you will enjoy the ride.
1. COSY
The
acronym is used for “COrrelation SpectroscopY”, which is a two dimensional NMR
technique, employed for the detection of scalar (through bonds) couplings
between protons geminal or vicinal to each other.
2. NOESY
Do
not poke in your “nosey”, because NOESY stands for “Nuclear Overhauser
Enhancement SpectroscopY”, a two dimensional NMR technique frequently used for
determining the stereochemistry at different centers in a compound. NOESY is
based on dipolar (through space) couplings.
3. ROESY
ROESY
is not the name of any girl, but an NMR acronym used for “Rotating-frame
Overhauser Enhancement SpectroscopY”. The technique is slightly different from
NOESY, but affords the same information (stereochemistry) about a compound.
4. INADEQUATE
Please
do not feel “inadequate” when you are using INADEQUATE, a powerful NMR technique
used for determining the carbon framework within the molecule. The abbreviation
stands for “Incredible Natural Abundance DoublE QUAntum Transfer Experiment”.
5. DOSY
Diffusion
Ordered SpectroscopY (DOSY) is a two dimensional NMR technique used for a
mixture of compounds. The technique can effectively differentiate between
signals from each compound.
6. HOHAHA
Well,
this not something for scaring you. HOHAHA means “HOmonuclear HArtmann HAhn”,
also known as TOCSY (TOtal Correlation SpectroscopY). This technique can be considered
as a long range COSY, as it can correlate all protons in a spin system (a
network of carbon atoms bearing hydrogens).
7. SECSY
SECSY
is in no way related to being “sexy”. Spin Echo Correlation SpectroscopY (SECSY)
makes use of the 2D J-resolved spectrum in NMR for structure determination of
compound.
8. STD
Sexually
Transmitted Diseases (STD) are unquestionably a concern as far as the medical
science is concerned. But what helps the medical science ascertain the cause of
a health disorder or in identifying drug candidates is the STD (Saturation
Transfer Difference) NMR technique. STD-NMR can effectively recognize the
interaction of the active site of an enzyme with any molecule (epitope mapping).
9. DEPT
No
need to go in “Depth”, DEPT is just an NMR technique, known as “Distortionless
Enhancement by Polarization Transfer”. DEPT experiments are used for the
identification of different types (methyl, methylene, methine, quaternary) of
carbons in a molecule.
10. dd
You must have heard about “Dee Dee”, Dexter’s
sister. If not, ask somebody. In NMR, “dd” is just a splitting pattern called “double
doublet” or “doublet of a double”. This pattern is observed for a proton having
two chemically and magnetically inequivalent protons in its vicinity.
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