Phosphazenes – Preparation, Properties and Uses

Phosphazenes are a fascinating group of compounds that have been studied for decades, yet continue to surprise researchers with their remarkable properties and diverse applications. From flame retardants and biomedical materials to catalysts and electronic devices, these polymer compounds prove time and again that they are versatile tools in the chemist’s toolbox. In this post, we delve into the world of phosphazenes, exploring their unique characteristics and exciting potential uses. So buckle up and get ready for a journey through the wonders of these intriguing molecules!

What are Phosphazenes?

Phosphazenes are a class of inorganic polymers with the general structure RnE(PN)x. In this structure, R represents an organic group, E is a central phosphorus atom, P is a pnictogen (nitrogen or phosphorus), and n represents the number of atoms in the ring. The most common phosphazene is hexamethylphosphoramide, (H3C)6N3P.

The term “phosphazene” was coined in 1953 by American chemist Harold Brode.

These polymer compounds have many interesting properties: they are insoluble in water but soluble in organic solvents, they have high thermal and chemical stability, and their electrical conductivity can be tuned by changing the organic groups attached to the phosphorus atom.

Because of these properties, they have potential applications in fields as diverse as electronics, optoelectronics, solar energy conversion, drug delivery, and biocompatibility.

Types of Phosphazenes

These polymer compounds are inorganic polymers that contain nitrogen and phosphorus atoms. The most common type of phosphazene is hexamethylphosphorus triamide, also known as hexamethylphosphoramide or HMPA. Other types of phosphazenes include dialkylphosphoramides, diarylphosphoramides, and alkylarylphosphoramides. These polymer compounds have a variety of uses, including as lubricants, surfactants, and corrosion inhibitors.

Properties of Phosphazenes

They are a class of inorganic polymers containing nitrogen and phosphorus atoms. These compounds have a variety of properties that make them useful for a range of applications. They are generally insoluble in water, but they can be modified to be more water-soluble. They are also flammable and have a high thermal stability. Phosphazenes are used in the manufacture of plastics, adhesives, and coatings. They can also be used as catalysts, fire retardants, and lubricants.

Uses of Phosphazenes

Phosphazenes are a class of polymeric compounds containing nitrogen and phosphorus atoms. The structure of these polymer compounds consists of alternating phosphorus and nitrogen atoms in a six-membered ring. Phosphazenes are classified as either primary, secondary, or tertiary, depending on the number of nitrogen atoms bonded to the phosphorus atom.

They have a variety of uses due to their unique chemical and physical properties. For example, primary phosphazenes are highly reactive and can be used as catalysts or cross-linking agents. Secondary phosphazenes are less reactive and are often used as precursors for other chemicals. Tertiary phosphazenes are the most thermally and chemically stable of the three types and find use as high temperature polymers or in coatings.

How to make Phosphazenes

These are a class of nitrogen-containing inorganic compounds characterized by the presence of phosphorus-nitrogen bonds. The simplest of these polymer compounds is H2N3P, or PH3. They can be prepared by the reaction of primary amines with phosphine or its derivatives:

RNH2 + PCl3 -> RNH3+PCl4

Other methods for the synthesis of phosphazenes include the reactions of isocyanates with phosphites or phosphine oxides:

NCO + POCl3 -> N[OPCl2]+[Cl]


As we have seen, phosphazenes are a type of polymers that can be used in a variety of applications. Their versatility and unique properties make them an attractive option for many different industries. With their ability to withstand high temperatures and their biodegradability, they offer a range of possibilities for the future. We look forward to seeing more of these polymer compounds being developed in the coming years as chemists continue to explore this fascinating class of materials.