Analytical Chemistry Survey
CHEM 824
2/6/2016
Nuclear Magnetic Resonance (NMR)
Main Goals:
A. Understanding Basic principals of NMR:
a. What is the origin of the NMR signal?
b. How is the NMR signal related to both Quantum and Classical theory?
c. How does basic NMR theory relate to our understanding of
i. Observed Frequency
ii. Sensitivity
iii. Resolution
iv. Relaxation
v. Coupling.
d. Factors affecting an NMR spectra quality:
i. Sample size (concentration)
ii. S/N vs. acquisition
iii. Sample complexity
iv. Magnetic Field
v. Molecular Weight
e. How is an NMR signal obtained and processed?
i. Time-domain vs. CW
ii. Fourier Transform
iii. NMR pulses
iv. Window Functions
v. Zero-filling
vi. Quadrature detection
B. Understanding the different components of an NMR spectra:
a. Chemical shift
b. Coupling Constant
c. Peak Intensity
d. Line-width
e. NOE
C. Understanding basic components of an NMR spectrometer:
a. Magnet
b. Receiver (digital acquisition)
c. Transmitter (B1 field, RF pulses)
d. Computer
D. Understanding how NMR spectra relate to:
a. Chemical structures
i. Local environment affect on chemical shifts
1. Empirical trends and predicting chemical shifts
ii. Information content of 1H and 13C spectra
Analytical Chemistry Survey
CHEM 824
2/6/2016
iii. Coupling constants identify covalently bonded nuclei
1. Coupling patterns and coupling constants
iv. Determining a structure from NMR data
b. Dynamic processes & Exchange/Equilibrium
i. Related to line-width, chemical shifts
ii. NMR resonance frequency indicates both an energy (E=h) and
time (Hz=sec-1)
E. Understanding Basic Principals of Multidimensional NMR:
a. NMR experiments are composed of :
i. Various length RF pulses (90o, 180o)
ii. Various Delay times (D)
iii. Acquisition times (t1, t2)
b. Multiple-time domains and Multiple Fourier Transforms
c. Correlate peaks through coupling constants and NOEs
d. Increased resolution, simplify complex problems