Temperature dependence of NMR secondary references for D2O and (CD3)2SO solutions

Chemical shifts of secondary references for D2O and (CD3)2SO solutions were measured as a function of temperature. The 1H and 13C chemical shifts of dioxane, sodium 4,4‐dimethyl‐4‐silapentanesulphonate, HOD, tetramethylammonium chloride and sodium 3‐(trimethylsilyl)propionate‐d4 in D2O solution were measured relative to external TMS and the chemical shifts of (CD3)2SO and H2O were measured in (CD3)2SO solution relative to internal TMS. For accurate comparison of chemical shifts it is necessary to take into account the sample temperature and, therefore, the temperature dependences of 1H and 13C chemical shifts of a number of secondary references have been determined accurately and fitted to a parabola or straight line, as appropriate.