This thesis describes the use of supramolecular chemistry in self-assembling systems based on pyridyl porphyrins and porphyrin nanorings. Pyridine substituted porphyrins are used as ligands to bind to Zn porphyrin nanorings in systems reminiscent of the light harvesting complexes in nature. The study of energy transfer in such complexes gives insight into the efficiency of the natural systems. This thesis also illustrates the scope of classical and Vernier templating as an alternative tool for the synthesis of linear porphyrin oligomers. Chapter 1 gives a general overview of porphyrins and fully conjugated porphyrin oligomers, and then introduces supramolecular self-assemblies based upon pyridyl porphyrin ligand interactions. It also covers energy transfer processes in the selected synthetic porphyrin arrays, and includes a short review of template-directed synthesis of cyclic, linear and Vernier porphyrin oligomers. Chapter 2 presents the syntheses and energy transfer studies of double- and triple-strand complexes based on porphyrin nanorings. The arrangement of the porphyrin units in the double-strand nanoring complex mimics the LH2 structure of purple bacteria in natural light harvesting systems. The presence of a second nanoring in the triple-strand structure should fix the conformation of the complex, enhancing the conjugation around the nanorings. Chapter 3 introduces a synthetic antenna-nanoring system based on a series of conjugated porphyrin arrays. By varying the size of the acceptor nanoring, the effects of binding, local strain and energy transfer between antenna and nanoring are investigated. Binding of the antenna unit induces a local strain in the nanoring, and this strain is determined as a function of the size of the nanoring, providing information on the flexibility of the system. The rates of energy transfer in these systems were found to be surprisingly insensitive to the size of the nanoring. Chapter 4 presents the classical template-directed synthesis of linear porphyrin oligomers. The stabilities and cooperativities of related ladder complexes are investigated. Two concepts of Vernier and Vernier-reciprocal templates for the synthesis of non-commensurate length oligomer products from two simple components are also introduced and investigated in detail. This study gives another approach for the supramolecular synthesis of nanoscale materials.