Phosphorus complexes of porphyrinoid macrocycles

Phosphorus complexes of porphyrinoids such as porphyrins, corroles, N-fused porphyrins, N-fused expanded porphyrins and expanded porphyrins can be prepared readily by treating the porphyrinoid with phosphorylating agents such as PX3, PX5 and POX3 (X = Cl or Br) under standard reaction conditions. In phosphorus porphyrinoids, the phosphorus is generally high valent +5 oxidation state and the coordination number is varied from four to six. The insertion of P(V) into porphyrinoids alters the structure and electronic properties of the macrocycle significantly. Specially, the phosphorus binding mode is different from one porphyrinoid to another. The oxophilicity nature of P(V) in P(V) porphyrinoids is very useful to change variety of axial ligands and also helps to synthesize multi-porphyrin arrays by axial bonding approach. This review summarizes the phosphorus complexes of five different porphyrinoids and discusses their structure and electronic properties as well as their applications in the synthesis of more elaborate P(V) porphyrinoid based architectures.