Formula Used:
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Definition: The observed width at half-height (Δν1/2) is the phenomenological linewidth of the resonance lineshape in NMR spectroscopy.
Purpose: It's a primary factor affecting both resolution and signal-to-noise ratio of NMR spectra.
The calculator uses the formula:
Where:
Explanation: The linewidth is inversely proportional to the transverse relaxation time, with π as the proportionality constant.
Details: Understanding linewidth helps in optimizing NMR experiments, interpreting spectra, and assessing sample quality.
Tips: Enter the transverse relaxation time (T2) in seconds. The value must be > 0.
Q1: What affects the transverse relaxation time (T2)?
A: T2 is affected by molecular motion, magnetic field inhomogeneity, and spin-spin interactions.
Q2: What's a typical T2 value for liquids?
A: For small molecules in solution, T2 is typically in the range of 0.1 to several seconds.
Q3: How does linewidth relate to spectral resolution?
A: Narrower linewidths (smaller Δν1/2) result in better resolution of closely spaced peaks.
Q4: What causes line broadening in NMR spectra?
A: Factors include short T2, magnetic field inhomogeneity, chemical exchange, and restricted molecular motion.
Q5: How can I measure T2 experimentally?
A: T2 can be measured using spin-echo experiments like the Carr-Purcell-Meiboom-Gill (CPMG) sequence.