The synthesis, use and X-ray crystal structure of the novel cyclooctadiene Pd–triflate methyl complex 1 is described. Evidence for ionization of the triflate ligand in 1 in solution is presented through IR, 19F-NMR and conductivity measurements. The high reactivity of this starting material is exemplified through the preparation of the novel cationic pentacoordinate Pd complexes 4 and 5, from 1 and the sterically demanding 2,9-diarylsubstituted 1,10-phenanthroline ligands 2 and 3. Complexes 4 and 5 have a pseudo-trigonal bipyramidal structure and display significant differences of the binding mode of the two olefin moieties of the cyclooctadiene ligand. This has been substantiated through 1H- and 13C-NMR spectroscopic data and for complex 4 by an X-ray crystallographic study.