What is the Difference Between Phthalocyanine and Porphyrin

Thekey difference between phthalocyanine and porphyrinis that phthalocyanine molecules contain four indole units or吡咯rings linked through氮atoms that are conjugated with苯环，而卟啉分子包含四个通过甲烷碳桥连接的吡咯环。

Phthalocyanine or H2Pc is a large, aromatic, macrocyclic organic compound having the formula (C8H4N2)4H2. Porphyrin compounds are theconjugate acidsof ligands that can bind with metals forming complexes.

内容

1.Overview and Key Difference
2.什么是邻苯二甲胺
3.What is Porphyrin
4.Phthalocyanine vs Porphyrin in Tabular Form
5.Summary – Phthalocyanine vs Porphyrin

什么是邻苯二甲胺?

Phthalocyanine or H2Pc is a large, aromatic, macrocyclic organic compound having the formula (C8H4N2)4H2. It has theoretical and specialized interests in chemical dyes and photoelectricity. This substance has four isoindole units that are linked to each other through a ring of nitrogen atoms. This compound has two-dimensional geometry and a ring system containing 18 pi electrons. There is extensive delocalization of the pi electrons, which can cause the molecule to have useful properties which can lend themselves to applications in dyes and pigments. Moreover, the derivatives of this compound, such as metal complexes, are significant in catalysis, organic solar cells, and photodynamic therapy.

此外，邻苯二甲胺化合物及其金属络合物能够聚集，因此，它们在常见溶剂中的溶解度较低。例如，当考虑相同的温度时，苯的溶解度低于邻苯胺。此外，大多数邻苯烷酸化合物是热稳定的，而它们在升华的情况下，而无需在高温下进行熔化。

When considering the synthesis of phthalocyanine, it forms through the cyclotetramerization of various phthalic acid derivatives such as phthalonitrile, diiminoisoindole, phthalic anhydride, and phthalimides. In addition, we can also use the method of heating phthalic anhydride when there is enough amount of urea present to get H2Pc.

邻苯烷氨酸的主要用途是将其用作染料和颜料。然而，该分子中的修饰对于调整PC的吸收和发射特性以产生不同的颜色染料和颜料很有用。其他衍生物也可用于光伏，光动力疗法，纳米颗粒结构和催化。

什么是卟啉？

Porphyrin compounds are the conjugate acids of ligands that can bin with metals forming complexes. The metal ion of this complex is typically a +2 or a +3 charged cation. We can call a porphyrin compound without a metal ion in its cavity a “free base.” There are some complexes that contain iron at the metal center. We call them “heme complexes” or simply “hemes.” There are proteins consisting of iron which are known as hemoproteins. We can find this type of protein extensively in nature. Moreover, there are two major oxygen binding proteins in our blood named hemoglobin and myoglobin. They are iron porphyrins. Besides, there are various different cytochromes that we can name hemoproteins.

H₂porphyrin + [ML_n]²⁺→ M(porphyrinate)L_n−4+ 4 L + 2 h⁺, where M = metal ion and L = a ligand

What is the Difference Between Phthalocyanine and Porphyrin?

Phthalocyanine or H2Pc is a large, aromatic, macrocyclic organic compound having the formula (C8H4N2)4H2. Porphyrin compounds are the conjugate acids of ligands that can bin with metals forming complexes. The key difference between phthalocyanine and porphyrin is that phthalocyanine molecules contain four indole units or pyrrole rings linked through the nitrogen atoms that are conjugated with benzene rings, whereas porphyrin molecules contain four pyrrole rings linked through methane carbon bridges.

The below infographic presents the differences between phthalocyanine and porphyrin in tabular form for side by side comparison.

Summary – Phthalocyanine vs Porphyrin

邻苯丙氨酸和卟啉之间的关键区别在于，邻苯丙氨酸分子包含四个吲哚单元或与苯环子偶联的氮原子相连的吡咯环，而卟啉分子包含四个吡咯酸环通过甲烷碳纤维链接的四吡咯环循环。

Reference:

1. Lopes, David M., et al.“Technological Applications of Porphyrins and Related Compounds: Spintronics and Micro-/Nanomotors。”Intechopen，2019年5月10日。

Image Courtesy:

1.“”Phthalocyanine” By Choij – Own work (Public Domain) via Commons Wikimedia
2. “Copper Phtalocyanine Blue” By Shangy (talk) – Own work (Public Domain) via Commons Wikimedia