Abstract: The present invention relates to metal complexes, processes for their preparation and their use as pharmaceutical or veterinary agents, in particular for the treatment of conditions in which metal delivery can prevent, alleviate or ameliorate the condition. There are a number of clinical conditions which are caused by or associated with abnormal levels of metals (typically low metal levels). Conditions in of this type include cancer and conditions characterised by or associated with oxidative damage, more specifically neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease or Huntington's disease. The invention also relates to ligands useful in the preparation of metal complexes of this type.