This book cuts across the divisions of organic, inorganic, and physical chemistry. It describes new methods for creating π-conjugated porphyrin oligomers with precisely defined sequences of zinc and copper metal cations, and how EPR spectroscopy was used to investigate the dipolar and exchange coupling between the paramagnetic copper(II) centres. Porphyrins are a group of heterocyclic macrocycle organic compounds that play an important role in our everyday life and can for example be found in blood where they form a red complex with iron (haem). Various metallic elements can be inserted into a porphyrin and changing the coordinated metal is an excellent way to influece the chemical and physical properties of these molecules. Focusing on 3 metals - zinc, magnesium and copper - the author established new methods for creating π-conjugated porphyrin oligomers and lastly presents the synthesis and investigation of two novel porphyrin nanoballs.Giving the template-directed strategy the author developed for constructing these molecules, this work could provide access to other related nano-cages.