answer to name a complex we start by working out the oxidation number of the central metal atom and then add the names of the ligands in alphabetical order a the complex has two anionic ligands cl- four neutral ligands nh3 and an overall charge of +2 hence the oxidation number of platinum must be +4.according to the alphabetical order rules the name of the complex is tetraamminedichlorido-platinum. b the ligands co and pyridine are neutral so the oxidation number of nickel must be o if follows that the name of the complex is tricarbonylpyridinenickel o. this omplex contains the hexadented edta 4- ion as the sole ligand.