Fig. 3: ¹¹B NMR spectra and REDOR data.

a ¹¹B MAS NMR spectra of the unaltered irradiated sample (pink line), irradiated and altered sample (red line), the unaltered non-irradiated sample (cyan line), and the non-irradiated and altered sample (navy-blue line). b ¹¹B MAS NMR spectra of the irradiated and altered (red line) and the non-irradiated and altered sample (navy-blue line) after the samples were heated again at 50 °C. c ¹¹B Echo, ¹¹B {¹H} REDOR corresponding to the BO₄¹ component at ~ −0.5 ppm, and the delta for the non-irradiated and altered sample and d ¹¹B Echo, ¹¹B {¹H} REDOR corresponding to the BO₄¹ component at ~ −0.5 ppm, and the delta for the irradiated and altered sample.