Figure 2: 13C cross-polarization magic angle spinning solid-state NMR of the Nx–COFs.
From: A tunable azine covalent organic framework platform for visible light-induced hydrogen generation
The azine C=N peak (marked a) appears at ≈160 p.p.m. while the phenyl peaks (marked b) and characteristic central aryl peaks (marked c,d,e) show minimal changes with respect to their precursor aldehydes.
