Ab initio RHF and density functional B3LYP and B3PW91 study of (NPF2)n; n=2,3,4 and (NPX2)3; X=H, Cl, Br cyclic phosphazenes

Sabzyan, Hassan; Kalantar, Zahra

doi:10.1016/j.theochem.2003.08.132

Cited by 23 publications

(13 citation statements)

References 15 publications

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“…The obtained results at the MP2//6-31G* level agree with those of B3LYP/6-31G* with errors varying between 0.002 and 0.039 Å. electronegativity of the halogen substituents on the phosphorus atom [17]. Our study shows a similar behavior as far as the electronegativity effect is concerned with the short phosphazenes (R 3 PNH, R 3 PNF and R 3 PNOH with R = H, F) ( Fig.…”

Section: -1-a Geometrysupporting

confidence: 84%

“…Among the several bonding theories presented to explain the observed structural properties in cyclopolyphosphazenes, the d -p bonding model is the most widely adopted one [16,17]. This model, developed simultaneously by Craig et al [18] and by Dewar et al [19] describes the P=N bonding in terms of and -bonding arising from the overlap of 3d orbital of the phosphorus atom with the 2Pz orbital of the nitrogen one [17]. Allcock et al [20] have elaborated and studied a series of short-chain linear phosphazenes.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical Study of the Linear Short-Chain Phosphazene-Na+ Complexes

Abdellatif¹,

Maouche²,

Belmiloud³

et al. 2009

TOSBJ

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In this work, we study simples phosphazenes models, such as R-[R 2 P=N] n -X, with (X = H, F, OH), (R= H, F) and (n = 1, 2 and 3) with an attempt to answer the type of Natural Hybrid Orbital (NHO) able to form this -bond in the phosphazene-Na + complex and the Na + effect on the geometry and the electronic distribution of the studied molecules by using the HF and DFT studies of electronics, molecular structures and Natural Bond Orbital (NBO) analysis. The substituent effect of the fluorine atom acceptor and the OH group donor is studied. The phosphazene polymers doped by Na + cation, linearize all the PNP bond angles.The geometries of all the systems were optimized using Berny algorithm [33] within higher accuracy (keyword opt=

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Section: -1-a Geometrysupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Theoretical Study of the Linear Short-Chain Phosphazene-Na+ Complexes

Abdellatif¹,

Maouche²,

Belmiloud³

et al. 2009

TOSBJ

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“…We find that the molecules have a sharp peak between 3,500 cm −1 −3,700 cm −1 correspond to the stretching vibration of the N-H bond. The modes rang from 22,00 cm −1 −2,350 cm −1 and 1,300 cm −1 −1,360 cm −1 have been identified as the stretching vibrations of the −N 3 group, while the peaks at 1,266 cm −1 (1,689 cm −1 ) and 1,371 cm −1 (748 cm −1 ) are attributed to the in-plane stretching of P-N-P bonds, which are in agreement with the P-N-P stretch seen in (NPF 2 ) 4 [19]. The low vibration (470 cm −1 −920 cm −1 ) can be assigned to the bend of −NH 2 group and the torsion of −N 3 group.…”

Section: Resultssupporting

confidence: 52%

Theoretical Study for High-Energy-Density Compounds Derived from Cyclophosphazene. IV. DFT Studies on 1,1-Diamino-3,3,5,5,7,7-hexaazidocyclotetraphosphazene and Its Isomers

Zhang

Zheng

Zhang

et al. 2009

IJMS

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In the present study, a theoretical study of 1,1-diaminohexaazidocyclotetraphophazene (DAHA) and its isomers has been performed, using quantum computational density functional theory (B3LYP and B3PW91 methods) with 6-31G* and 6-31G** basis sets implemented in Gaussian 03 program suite. Molecular structure and bonding, vibrational frequencies, Milliken population analysis, and natural bond orbit (NBO) have been studied. The heats of formation from atomization energies have also been calculated based on the optimized geometry. The obtained heats of formation data are compared with their homologous cyclophosphazene in order to demonstrate the accuracy of the methods, which indicate that the studied compounds might be potentially used as high energetic materials. In addition, the relative stability of five isomers have been deduced based on the total energy and the gap of frontier orbital energies.

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“…[8] Cyclic phosphazenes such as P 3 N 3 (OC 6 H 4 CF 3 ) 4 (OC 6 H 4 F) 2 [9] are used as additives to lubricants. [10] Simple (PNX 2 ) 3 phosphazenes (X = H, F, Cl, NH 2 ) were studied by DFT and ab initio calculations, [9,[11][12][13][14][15][16] as well as normal coordinate analyses. [17][18][19][20][21] These investigations were also sparked by the special electronic structure of the phosphazene rings.…”

Section: Introductionmentioning

confidence: 99%

Silver Complexes of Cyclic Hexachlorotriphosphazene

Gonsior

Antonijevic

Krossing

2006

Chemistry A European J

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The first solid-state structures of complexed P3N3X6 (X = halogen) are reported for X = Cl. The compounds were obtained from P3N3Cl6 and Ag[Al(OR)4] salts in CH2Cl2/CS2 solution. The very weakly coordinating anion with R = C(CF3)3 led to the salt Ag(P3N3Cl6)2+[Al(OR)4]- (1), but the more strongly coordinating anion with R' = C(CH3)(CF3)2 gave the molecular adduct (P3N3Cl6)AgAl(OR')4 (3). Crystals of [Ag(CH2Cl2)(P3N3Cl6)2]+[Al(OR)4]- (2), in which Ag+ is coordinated by two phosphazene and one CH2Cl2 ligands, were isolated from CH2Cl2 solution. The three compounds were characterized by their X-ray structures, and 1 and 3 also by NMR and vibrational spectroscopy. Solution and solid-state 31P NMR investigations in combination with quantum chemically calculated chemical shifts show that the 31P NMR shifts of free and silver-coordinated P3N3Cl6 differ by less than 3 ppm and indicate a very weakly bound P3N3Cl6 ligand in 1. The experimental silver ion affinity (SIA) of the phosphazene ligand was derived from the solid-state structure of 3. The SIA shows that (PNCl2)3 is only a slightly stronger Lewis base than P4 and CH2Cl2, while other ligands such as S8, P4S3, toluene, and 1,2-Cl2C2H4 are far stronger ligands towards the silver cation. The energetics of the complexes were assessed with inclusion of entropic, thermal, and solvation contributions (MP2/TZVPP, COSMO). The formation of the cations in 1, 2, and 3 was calculated to be exergonic by delta(r)G(degrees)(CH2Cl2) = -97, -107, and -27 kJ mol(-1), respectively. All prepared complexes are thermally stable; formation of P3N3Cl5+ and AgCl was not observed, even at 60 degrees C in an ultrasonic bath. Therefore, the formation of P3N3Cl5+ was investigated by quantum chemical calculations. Other possible reaction pathways that could lead to the successful preparation of P3N3X5+ salts were defined.

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Ab initio RHF and density functional B3LYP and B3PW91 study of (NPF2)n; n=2,3,4 and (NPX2)3; X=H, Cl, Br cyclic phosphazenes

Cited by 23 publications

References 15 publications

Theoretical Study of the Linear Short-Chain Phosphazene-Na+ Complexes

Theoretical Study of the Linear Short-Chain Phosphazene-Na+ Complexes

Theoretical Study for High-Energy-Density Compounds Derived from Cyclophosphazene. IV. DFT Studies on 1,1-Diamino-3,3,5,5,7,7-hexaazidocyclotetraphosphazene and Its Isomers

Silver Complexes of Cyclic Hexachlorotriphosphazene

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