Linear Phosphazenes Research Articles

Phosphates branching effect on the structure, linear and NLO properties of linear phosphazenes

In this paper, we studied the structure, dipole moment, polarizability, and static first hyperpolarizability of linear phosphazenes. The relationship between the nonlinear optical (NLO) properties and the energy gaps was also taken into account. The structure of these phosphazenes has been performed using the B3LYP, ωB97X–D and M06–2X functionals. The linear and NLO properties of these compounds have shown selective responses to the different DFT levels that are in good agreement with the experimental values of similar compounds. The ωB97X–D functional gives a high static first hyperpolarizability compared to the B3LYP and M06–2X levels. An inverse relationship has been obtained between the HOMO–LUMO gaps and βtot. This theoretical study confirms the suitability of these phosphazenes for optoelectronic and optical devices.

Phosphazenes as Collective Extractants of Rare-Earth Elements

The extraction ability of some linear phosphazenes with respect to rare-earth elements (REEs) in a nitrate medium is studied. Some possible mechanisms of interaction between phosphazenes of different types and REEs at various acidities are discussed. It has been established that imido- and amidophosphazenes are very strong extractants of REEs within a broad range of nitric acid concentrations in the aqueous phase. It has been shown that phosphazenes can be efficient collective extractants of REEs.

ChemInform Abstract: Synthesis and Structure of Small-Molecule Cyclic Phosphazenes Bearing ortho-Substituted Aryloxy and Phenoxy Substituents.

A series of cyclic trimeric and tetramcric phosphazenes with ortho-substitutcd aryloxy side groups have been synthesized. The ortho substituents are methyl and phenyl groups. These compounds are structural models for the corresponding linear high-polymeric phosphazenes. X-ray structural analysis of the cyclic tetrameric species [NP(OC 6 H 4 CH 3 -2) 2 ] 4 (3), (NP(OC 6 H 4 C 6 -H 5 -2) 2 ] 4 (4) and [NP(OC 6 H 5 ) 2 ] 4 are reported

Synthesis, reactivity and structures of spirocyclic products derived from octachlorocyclotetraphosphazene: comparison with spirocyclic cyclotriphosphazenes and linear phosphazenes

The reaction of N4P4Cl8 1 with the difunctional reagents 2,2′-methylenebis(4,6-di-tert-butylphenol) (as its disodium salt) and N,N′-diisopropylpropane-1,3-diamine gave the spirocyclic products 2,2-N4P4{[O-4,6-(t-Bu)2C6H2]2CH2}Cl6 4 and 2,2-N4P4[N(i-Pr)CH2CH2CH2N(i-Pr)]Cl6 5. Further reaction of 1 with 2 mol equivalents of N,N′-diisopropylpropane-1,3-diamine afforded the novel dispiro derivative 2,2,6,6-N4P4[N(i-Pr)CH2CH2CH2N(i-Pr)]2Cl4 6. Whereas the analogous reaction of N3P3Cl6 2 with the above diamine gave the monospiro derivative 2,2-N3P3[N(i-Pr)CH2CH2CH2N(i-Pr)]Cl4 7 readily, the reaction of 2 with the diols CH2[4,6-(t-Bu)2C6H2OH]2 or CH2(4-Me-6-t-BuC6H2OH)2 is sluggish. In the case of the latter diol, a product formulated as N3P3[O-4-Me-6-t-BuC6H2-4-Me-6-t-BuC6H2OH]Cl5 9 was identified (31P NMR). The linear phosphazene Cl2P(O)NPCl3 3, by contrast, reacted with CH2(4-Me-6-t-Bu-C6H2OH)2 and Et3N to give the cyclic product Cl2P(O)NP[(O-4-Me-6-t-BuC6H2)2CH2]Cl 8. Reaction of the spirocycle 5 with an excess of MeNH2/Et3N afforded the new bicyclic phosphazene containing a spirocyclic ring N4P4[N(i-Pr)CH2CH2CH2N(i-Pr)](NHMe)4(NMe) as a crystalline solid. The crystal structures of 4·0.5C4H8Cl2 and 5–8 have been determined.

The versatile behavior of a 1,2λ 5-azaphosphete towards protic nucleophiles

1,2λ 5-azaphosphete 1 reacts with cyclohexylamine leading to five-membered phosphazenes 7 and 8. This result has been rationalized by the protonation of the ring nitrogen atom followed by nucleophilic attack of the amide at the β-carbon of the ring. Addition of p-cresol and p-thiocresol to 1 affords the linear phosphazenes 12 and 13, resulting from protonation of the α-carbon atom of the ring followed by nucleophilic attack at phosphorus. Compounds 7 and 12 have been characterized by single crystal X-ray diffraction studies.

ChemInform Abstract: Cyclic and Shortchain Linear Phosphazenes with Hindered Aryloxy Side Groups.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Cyclic and short-chain linear phosphazenes with hindered aryloxy side groups

A series of short-chain and cyclic phosphazenes bearing o-dichloro- and o-dimethyl-phenoxy groups have been synthesised, and their structures studied by X-ray crystallography. These compounds are small-molecule models for the corresponding linear high polymers. Structural parameters: N3P3Cl5(OC6H3Cl2-o)1, a= 8.081(4), b= 8.074(2), c= 25.868(3)A, β= 91.11(2)°, space group P21/c, Z= 4; gem-N3P3Cl4(OC6H3Cl2-o)22, a= 18.856(5), b= 8.002(2), c= 16.124(2)A, β= 114.89(2)°, space group P21/c, Z= 4; N3P3Cl2(OC6H3Cl2-o)44, a= 7.975(3), b= 18.373(4), c= 22.225(3)A, β= 90.35(2)°, space group P21/n, Z= 4; [NP(OC6H3Cl2-o)2]35, a= 12.021(4), b= 19.938(5), c= 18.379(11)A, β= 90.84(5)°, space group P21/n, Z= 4; gem-N4P4Cl4(OC6H3Cl2-o)46, a= 10.806(2), b= 10.861(2), c= 17.075(7)A, α= 89.33(4), β= 80.79(3), γ= 68.44(2)°, space group P1, Z= 2; gem-N3P3Cl4(OC6H3Me2-o)27, a= 9.470(3), b= 18.481(12), c= 13.087(8)A, β= 94.56(4)°, space group P21/n, Z= 4; [NP(OC6H3Me2-o)2]38, a= 20.560(5), b= 20.580(9), c= 22.085(4)A, α=β=γ= 90.0°, space group P4/ncc, Z= 8; OPCl2NP(OC6H3Cl2-o)39, a= 14.319(4), b= 16.837(4), c= 20.660(8)A, space group Pbca, Z= 8; OPCl(OC6H3Me2-o)NPCl(OC6H3Me2-o)NP(OC6H3Me2-o)310, a= 15.212(3), b= 18.965(1), c= 14.559(2)A, β= 102.96(2)°, space group P21/c, Z= 4. Despite the bulkiness of the o-dichloro- and o-dimethyl-phenoxy groups, their introduction into the phosphazene structure followed a geminal substitution pathway during the early stages of the reaction. In the reactions with the linear short-chain oligomers these nucleophiles preferentially attacked at the terminal PCl3 rather than at the PCl units in the middle of the chain or those associated with the phosphoryl group. The structure of compound 10 revealed a distorted trans-trans conformation for the PN skeleton, in contrast to the cis-trans arrangement generally believed to exist for linear phosphazene high polymers.

ChemInform Abstract: Syntheses and Structures of Cyclic and Short‐Chain Linear Phosphazenes Bearing 4‐Phenylphenoxy Side Groups.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Syntheses and structures of cyclic and short-chain linear phosphazenes bearing 4-phenylphenoxy side groups

Syntheses and structures of cyclic and short-chain linear phosphazenes bearing 4-phenylphenoxy side groups

Conformation, bonding, and flexibility in short-chain linear phosphazenes

Conformation, bonding, and flexibility in short-chain linear phosphazenes