Substituent exchange reactions of trimeric and tetrameric aryloxycyclophosphazenes with sodium 2,2,2-trifluoroethoxide

Abstract

Substituent exchange reactions of sodium 2,2,2-trifluoroethoxide with trimeric and tetrameric aryloxycyclophosphazenes with phenoxy, 4-formylphenoxy, 4-cyanophenoxy and 4-nitrophenoxy side groups were conducted at 66 °C in THF and monitored by (31)P NMR and mass spectrometry. These are model reactions for their counterparts with high polymeric linear organophosphazenes. The ease of displacement of OAr in cyclic trimeric and tetrameric molecules by CF(3)CH(2)O increased significantly with the presence of electron-withdrawing substituents in the polyphosphazene in the order, phenoxy ≪ 4-formylphenoxy < 4-cyanophenoxy ≈ 4-nitrophenoxy. Fully substituted 2,2,2-trifluoroethoxyphosphazene trimer and tetramer were formed by side group exchange, but these reactions were followed by an attack by the nucleophile on the α-carbon of the 2,2,2-trifluoroethoxy groups linked to phosphorus to give a species in which one trifluoroethoxy group had been replaced by an ONa unit, and bis(trifluoroethyl) ether was formed as a side product. On the other hand, only partly exchanged species were formed when sodium phenoxide reacted with the trifluoroethoxy phosphazene trimer and tetramer, but again a product with an ONa side group was formed eventually together with phenyltrifluoroethyl ether generated via alpha-carbon attack. The relative sensitivity of 2,2,2-trifluoroethoxy and phenoxyphosphazene cyclic trimers and tetramers to the presence of trifluoroethoxide was established.

Fluorinated Hyperbranched Cyclotriphosphazene Simultaneously Enhances the Safety and Electrochemical Performance of High‐Voltage Lithium‐Ion Batteries

“…The prepared alkoxide was treated with hexachlorocyclotriphosphazene to afford the target compound, replacing the chloro groups through a S N Ar‐type pathway (Figure b). The 1 H NMR spectrum shows a multiplet peak with a chemical shift of 4.50–4.42 ppm, corresponding to OC H 2 CF 3 (Figure S2 a), which matched well with a previous reference . The 13 C NMR spectrum unveils two characteristic carbon peaks at 124.2 and 63.9 ppm, which are assigned to OCH 2 ‐ C F 3 and O‐ C H 2 ‐CF 3, respectively (Figure S2 b).…”

“…HFEPN was prepared from the modified method reported by Allcock and co‐workers . Sodium 2,2,2‐trifluoroethoxide was generated in situ by the addition of sodium metal into a solution of 2,2,2‐trifluoroethanol in diethyl ether.…”

Novel Coumarin Substituted Water Soluble Cyclophosphazenes as “Turn-Off” Type Fluorescence Chemosensors for Detection of Fe3+ ions in Aqueous Media

“…When BR^is the halogen, it can be replaced with ease by alkoxy, aryloxy or amino groups via nucleophilic substitution reactions [1][2][3][4][5][6]. Hexachlorocyclotriphosphazene, trimer, N 3 P 3 Cl 6 , (1) or octachlorocyclotetraphosphazene, tetramer, N 4 P 4 Cl 8 (2) namely cyclophosphazenes are a kind of phosphazene compounds that they show many special characteristics.…”

Synthesis and Characterisation of Phosphazene Derivatives Containing Dioxybiphenyl and 4-Sulfanylquinazoline Groups

“…[1][2][3][4] The variety of substitution reactions of the reactive P-Cl bonds provide a wide range of cyclophosphazene derivatives which have diverse applications. [5][6][7][8][9][10] These derivatives are usually prepared by nucleophilic substitution reactions using alcohol, phenol, amines, Grignard reagents and thiols. 11,12 Their physical and chemical properties can be tailored by appropriate substituents on the phosphorus atoms.…”