Plz check ..this line means that ..an elemant which has more negative reduction potential does not gain electrons easily therefore it is a weak oxidinzi.age

Reduction potential (also known as redox potential, oxidation/reduction potential, or Eh) measures the tendency of a chemical species to acquire electrons and thereby be reduced. ....

In general, a decrease in reduction potential upon complex formation has been observed. This means that the higher oxidation states of the metal ion become more stable after comple...