The Temperature Dependence of the Diamagnetic Shielding Correction for Proton NMR in Water

The fractional frequency shift in the nmr signal from protons in a spherically-shaped pure water sample has been measured directly as -10.36(30) × 10-9 °C-1 over the range 5 °C to 45 °C. A revised value of 25.69(14) × 10-6 is suggested for the proton diamagnetic shielding correction in water at 25 °C, leading to μ'p(25 °C)/μB = 0.001 520 993 136(17).