Phosphorus(V) porphyrins hold an important place in porphyrin chemistry. The hexacoordinated phosphorus center in these porphyrins has a formal oxidation state of +5 and is, thus, extremely electron deficient. As a result, the midpoint potential for oxidation of the phosphorus(V) porphyrin is shifted to a much higher value (1.66 V for PTPP+) compared to the corresponding free-base porphyrin (1.01 V for H2TPP) or zinc(II) porphyrin (0.79 V for ZnTPP). In addition, the phosphorus center provides two axial sites for the covalently binding of substituents, allowing a greater range of possibilities for attaching donors and acceptors. By exploiting these properties several ‘axial-bonding’ type Donor-Acceptor systems have been prepared consisting of octaethylporphyrinatophosphorus(V) (POEP+) and tertaphenylporphyrinatophosphorus(V) (PTPP+) units. The unique structural topology of the octaethylporphyrinatophosphorus(V) (POEP+) and tertaphenylporphyrinatophosphorus(V) (PTPP+) enabled the construction of mono- and di-substituted phosphorus(V) porphyrin-naphthalene conjugates, respectively. Transient absorption studies revealed rapid deactivation of singlet excited phosphorus(V) porphyrin due to the reductive electron transfer process. I will present some of these examples and discuss their structural, redox, and photophysical properties. Figure 1