Temperature is an often overlooked parameter when recording NMR spectra. Temperature directly affects molecular dynamics so changing the temperature can change the appearance of an NMR spectrum. Peaks, particularly those of exchangeable protons, move as the temperature is altered. Interconversion of conformers can be slowed or increased with temperature so that peaks can separate or coalesce. This allows determination of thermodynamic parameters, as long as the temperature can be accurately measured. All modern NMR spectrometers provide temperature control, but the systems need to be calibrated.
