Zhao, L.; Zhang, Y.-J.; Zhang, S.-T.; Guo, H.-X.; Cheng, Q. Synthesis and Dipolymer Structure of Salen-Type N2O2 Ligand 2,2’-[(Pentane-1,5-Diyldioxy-Bis)-Bis-(nitrilomethylidyne)]dinaphthalene. ajc 2013, 25, 4678-4680.