A molecular structure. In one embodiment, the molecular structure includes a nanotube formed With a plurality of carbon atoms having a first end, an opposite, second end, and a body portion defined there between, wherein the body portion has an interior surface defining a cavity, an opposite, exterior surface and a longitudinal axis therethrough the cavity, and a porphyrin molecule having a plurality of carbon atoms and a first plurality of hydrogen atoms, wherein at its original state the porphyrin molecule has a plurality of pyrrole units and each pyrrole unit is coupled to another pyrrole unit through a methine bridge so as to form a ring structure with a second plurality of hydrogen atoms positioned peripherally along the ring structure. The porphyrin molecule is chemically coupled to the interior surface of the nanotube such that at least one of the second plurality of hydrogen atoms positioned peripherally along the ring structure is replaced by a carbon atom of the nanotube.