Complexation with pagoda[n]arene (n=4, 5) protects ferrocenium from oxidation Gui-Hua Chen, Yi-Meng Duan, Ying Li, Xiao-Ni Han, Kun-Peng Wang, Zhi-Qiang Hu and Chuan-Feng Chen Abstract The complexation behaviors of pagoda[n]arenes (n=4, 5) with ferrocene, ferrocenium and analogues cobaltocenium were studied. The inclusion complexes of pagoda[n]arenes can protect ferrocenium from oxidation in organic solvents and improve the stability and oxygen resistance of ferrocenium.