Cyclotriphosphazene: A Versatile Building Block for Diverse Functional Materials

Cyclotriphosphazene (CP) is a cyclic inorganic compound with the chemical formula N3P3. This unique molecule consists of a six-membered ring composed of alternating nitrogen and phosphorus atoms, each bonded to two chlorine atoms. CP exhibits remarkable versatility and significance in the realm of materials chemistry due to its easy functionalization via facile nucleophilic substitution reactions in mild conditions as well as intriguing properties of resultant final CP-based molecules or polymers. CP has been served as an important building block for numerous functional materials. This review provides a general and broad overview of the synthesis of CP-based small molecules through nucleophilic substitution of hexachlorocyclotriphosphazene (HCCP), and their applications, including flame retardants, liquid crystals (LC), chemosensors, electronics, biomedical materials, and lubricants, have been summarized and discussed. It would be expected that this review would offer a timely summary of various CP-based materials and hence give an insight into further exploration of CP-based molecules in the future.

A Review on Synthesis, Structural, Flame Retardancy and Dielectric Properties of Hexasubstituted Cyclotriphosphazene

Hexachlorocyclotriphosphazene is a ring compound consisting of an alternating phosphorus and nitrogen atom with two chlorine substituents attached to the phosphorus atom. The six chlorine atoms attached to this cyclo compound can be substituted with any different nucleophile that leads to changes in different chemical and physical properties. The major topics that were investigated in this research are the flame retardancy and dielectric properties of cyclotriphosphazene compounds. Cyclotriphosphazene compounds have high potential to act as a flame retardant, and this compound consists of two active elements attributed to its high flame-retardant character. This compound also demonstrated good ability as a flame retardant due to its low toxicity and less smoke produced. In addition, cyclotriphosphazene compounds were also investigated for their dielectric properties. Cyclotriphosphazene has high potential in the electrical field since it has dielectric properties that can be widely studied in the investigation of any potential application. This review presented literature studies focused on recent research development and studies in the field of cyclotriphosphazene that focused on synthesis, structural, flame retardancy, and dielectric properties of hexachlorocyclotriphosphazene compounds.

RETRACTED ARTICLE: Synthesis and characterization of trimeric phosphazene based ionic liquids with tetrafluoroborate anions and their thermal investigations

The quaternized compounds (PzIL1–9) reacted with sodium tetrafluoroborate (NaBF₄) to generate phosphazene based ionic liquids (PzILs), PzIL1a–9a. The newly synthesized ionic compounds (PzIL1a–9a) were verified using elemental CHN analyses and functional and spectroscopic (FTIR and ¹H, ¹³C, ³¹P-NMR) analyses techniques. The thermal properties of PzIL1a–9a were investigated using thermogravimetric analysis (TGA). According to the initial decomposition temperature values calculated based on the TGA thermograms, PzIL7a (213 °C) was recognized to be more thermally stable than the other PzILs studied. PzIL1a–9a exhibited good solubility in the water and demonstrate a typical dielectric relaxation behavior, conductivity levels for both low and high-frequency regions. AC conductivity mechanisms and dielectric relaxation behavior of each sample are investigated by fabricating parallel plate capacitors.