Porphyrins Cyclic organic structures containing tetrapyrrole rings(four joined rings, each consisting of four CH units and one NH unit) that have the important characteristic property of forming complexes with metal ions.

• 卟啉：包括了四吡咯环（四个连接的环，每个环包括了4个-CH基和1个-nh基）的环状有机结构，具有与金属离子形成复合物的特征。