Figure 8
Overlays of the 15N (60.8 MHz) CPMAS (12 kHz) spectra at room temperature of leucopterin hemihydrate and anhydrate acquired with different contact times to highlight signals due to protonated and non-protonated N-atom sites. Top: hemihydrate, acquired with contact times of 0.1 (red) or 4 ms (black); bottom: anhydrate, acquired with contact times of 0.1 (red) or 4 ms (black). |