1. Understanding NMR
Nuclear Magnetic Resonance (NMR) spectroscopy uses the magnetic properties of atomic nuclei to
determine physical and chemical properties of molecules. When placed in a strong magnetic field
(B₀), nuclei like ¹H precess at a characteristic Larmor frequency.
2. Hardware Components
Permanent Magnets: Generate the main B₀ field (horizontal direction). Higher
field strength = better resolution and sensitivity.
Transceiver Coil: The RF coil produces B₁ pulses perpendicular to B₀ to excite
the nuclei, then detects the NMR signal.
3. Solvents and References
Deuterated Solvents: CDCl₃, D₂O, DMSO-d₆ etc. provide a deuterium lock signal
and minimize solvent peaks.
TMS Reference: Tetramethylsilane defines 0 ppm for ¹H and ¹³C NMR. Toggle it in
the options.
4. Running an Experiment
1. Select a sample and appropriate solvent.
2. Adjust B₀ field strength and other parameters.
3. Choose a pulse sequence (start with "Single Pulse").
4. Click "Run Experiment" to acquire data.
5. View the FID, spectrum, and molecular structure in different tabs.
5. Pulse Sequences
Single Pulse (zg): Basic 90° pulse and acquire - standard 1D NMR.
Spin Echo: 90°-τ-180°-τ-acquire. Refocuses field inhomogeneity to measure true
T₂.
CPMG: Multiple 180° refocusing pulses for T₂ measurement.
COSY, HSQC: 2D experiments showing correlations between nuclei.