Fig. 4From: Eco-friendly approach to access of quinoxaline derivatives using nanostructured pyrophosphate Na2PdP2O7 as a new, efficient and reusable heterogeneous catalystSolid-state 31P-MAS NMR spectra of Na2PdP2O7 for frequencies of 6 and 12 kHz (a) asterisks indicate the rotation bands. Zoom on the isotropic signal (b)Back to article page