Nuclear Magnetic Resonance Spectroscopy:

NMR Spectrum:

The 60 MHz proton NMR spectrum of pure methanol as shown in Figure 35.06 exhibits two signals located at 3.35 and 4.80 ppm. The higher-field methyl signal (magenta) being three times as strong as OH signal (orange) at a lower field.

Cooling the methanol to -45°C, the larger higher-field signal changes to a doublet (J = 5.2 Hz) having the same chemical shift. The smaller signal moves downfield to δ5.5 ppm and splits into a quartet (J = 5.2 Hz). However, the relative intensities of signals remain unchanged.

Figure 35.06:: NMR Spectra of pure methonal at 30°C (left) and -45°C [1].

Ref.[1]. https://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/spectrpy/nmr/nmr2.htm.