Fig. 3. Excerpt of the ³¹P and ¹H NMR spectra of [P₄H][Al(OTeF₅)₄] in o-DFB (external lock: [D₆]acetone) at various temperatures. The sample was first measured at T = –40 °C, annealed stepwise to T = 0 °C and cooled down again to T = –40 °C afterwards.