The Phosphazenes (Phosphonitrilic Compounds).

Shaw, Robert A.; Fitzsimmons, Β. W.; Smith, Barry

doi:10.1021/cr60217a004

Cited by 178 publications

(77 citation statements)

References 150 publications

(302 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Phosphonitrilic chloride trimer, (NPC12)3, (I) and tetramer, (NPC12)4, (11) polymerize a t temperatures between 200 and 300' C to yield a series of higher polymers which include linear oils and elastomers, (NPC12),, (111) (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). The higher polymers produced by this process are believed to have molecular weights in excess of 100,000 (2).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Phosphonitrilic Compounds: Part I. The Mechanism of Phosphonitrilic Chloride Polymerization Capacitance, Conductance, and Electron-Spin Resonance Studies

Allcock¹,

Best²

1964

Can. J. Chem.

View full text Add to dashboard Cite

Capacitance and conductance measurements were carried out with molten (NPC12)3 and [NP(OCeHS)2]3 and dipole moments were determined in benzene solution. Attempts to detect free radicals in molten samples of the same compounds were unsuccessful. Evidence was obtained that homolytic or heterolytic phosphorus-nitrogen ring cleavage is not involved in the primary initiation process. The results favor, instead, a polymerization mechanism for (NPCl2)8 in which phosphorus-chlorine ionization is a preliminary step.

show abstract

Section: Introductionmentioning

confidence: 99%

“…The higher polymers produced by this process are believed to have molecular weights in excess of 100,000 (2).…”

Section: Introductionmentioning

confidence: 99%

Phosphonitrilic Compounds: Part I. The Mechanism of Phosphonitrilic Chloride Polymerization Capacitance, Conductance, and Electron-Spin Resonance Studies

Allcock¹,

Best²

1964

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…NMe2 213 36 198 41 102 7 169 14 111 2 44 32 PMe2 NMe2 239 8 224 21 102 2 195 100 137 2 44 24 AsMe2 NMe2 289 2 268 100 102 10 239 21 181 1 44 52 PMe2 Cl 230 14 215 27 93 12 195 20 137 12 35 82 AsMe2 Cl 274 27 259 100 93 25 239 10 181 -35 7 PMe2 PMe2 256 23 241 54 119 12 195 100 137 5 61 11 AsMe2 PMe2 300 29 285 17 119 16 239 18 181 5 61 20 AsMe2 AsMe2 344 33 329 1 163 3 239 14 181 2 105 31 PMe2 AsMe2 300 5 285 8 163 15 195 100 137 3 105 52 Die Angaben der relativen Intensität beziehen sich auf den stärksten Massenpeak mit 100%; Massen für 28 (2-ClC6H4)AsMe2 (9) Eine aus 71,7 g (374 mmol) 2-Chlorbrombenzol und 9,7 g (400 mmol) Magnesium in 300 ml Ether dargestellte Lösung von 2-Chlorphenylmagnesiumbromid wird unter Rühren und Stickstoffatmosphäre bei 0 °C tropfenweise mit 56 g (400 mmol) Dimethylch...…”

Section: Ausgangsverbindungenunclassified

“…Eine pseudoaromatische Wechselwirkung dieser Art wird für viele anorganische Ringsysteme der allgemeinen Formel (AB)n zwischen Atomen A der ersten und Atomen B der zweiten Achterperiode des Periodensystems postuliert [7][8][9][10].…”

unclassified

Alternativ-Liganden, XIV [1]. Neue Chelatliganden des Typs (2-Me₂E′C₆H₄)Si(EMe₂)Me₂ (E, E′ = N, P, As; Me = CH₃) / Alternative Ligands, XIV [1]. Novel Chelating Ligands of the Type (2-Me₂E′C₆H₄)Si(EMe₂)Me₂ (E, E′ = N, P, As; Me = CH₃)

Aslanidis

Grobe

1983

Zeitschrift Für Naturforschung B

View full text Add to dashboard Cite

Chelating ligands of the type (2-Me2NC6H4)Si(EMe2)Me2 (E = N, P, As) are prepared by ortho-lithiation of N,N-dimethylaniline followed by reaction with ClSi(NMe2)Me2 to yield (2-Me2NC6H4)Si(NMe2)Me2. Cleavage of the SiN-bond with MePCl2 affords (2-Me2NC6H4)Si(Cl)Me2, which on substitution with LiEMe2 (E = P, As) gives the corresponding ligands. Synthesis of (2-Me2E'C6H4)Si(EMe2)Me2 with E' = P or As is accomplished by producing 2-ClC6H4MgBr followed by reaction with either Me2E'Cl or ClSi(NMe2)Me2 to yield (2-ClC6H4)E'Me2 and (2-ClC6H4)Si(NMe2)Me2, respectively. The second donor group is introduced by Cl/Li exchange and reaction of the resulting lithium compounds with either ClSi(NMe2)Me2 or Me2E'Cl. (2-Me2PC6H4)Si(NMe2)Me2 and (2-Me2AsC6H4)Si(NMe2)Me2 then are used to prepare the additional four ligands with E, E' = P, As via (2-Me2E'C6H4)Si(Cl)Me2 by substitution with LiEMe2.

show abstract

“…Although the possibility of optical isomerism in cyclophosphazene derivatives, [(NPXY) n n=3,4] was first discussed many years ago [1], chiral properties of molecules have only recently been elucidated [2][3][4][5] and used to investigate reaction mechanisms [6,7]. The spermine-bridged cyclophosphazene compound 1 has been prepared previously [8] by reaction of cyclotriphosphazene with the tetrafunctional amine, spermine.…”

Section: Introductionmentioning

confidence: 99%

Structural and stereogenic properties of spiro- and ansa-substituted 1,3-propanedioxy derivatives of a spermine-bridged cyclotriphosphazene

et al. 2006

View full text Add to dashboard Cite

Reaction of 1,3-propanediol with the achiral spermine-bridged cyclophosphazene 1 at various molar ratios in THF gives a number of spiro-and ansa-derivatives that exhibit different stereogenic properties, viz. racemic, meso or achiral forms. As expected, spiro forms are preferred (giving mono-, di-, tri-and tetra-substitution), although significant amounts of mono-and di-substituted ansa derivatives also occur. A number of new structures have been characterized by NMR spectroscopy and X-ray crystallography in this work; mono-spiro 2, di-mono-ansa 6 and di-spiro/mono-ansa 8. The mono-ansa compound 3 was observed in solution by NMR spectroscopy but no evidence was found for the monospiro/monoansa 5, a necessary precursor of compound 8. The tri-spiro derivative 7 has been isolated and characterized by 31 P NMR spectroscopy, whereas the structures of the di-monospiro 4 (meso) and tetra-spiro 9 have been characterized previously. The stereogenic properties of many of the products have been confirmed by X-ray crystallography and/or by 31 P NMR spectroscopy on addition of the chiral solvating agent, (S)-(+)-2,2,2-trifluoro-1-(9-anthryl)ethanol.Although the starting compound 1 is achiral, it is found that unsymmetrically-substituted derivatives with 1,3-propanediol give racemic mixtures for the mono-spiro 2 and tri-spiro 7 derivatives, whereas symmetrically-substituted derivatives such as di-mono-ansa 6 and dispiro/mono-ansa 8 are meso. It is found that care must taken in interpreting the 'splitting' of 31 P NMR signals on addition of CSA in terms of 'chirality' of molecules, because some meso compounds give false positive results due to changes from A 2 X-like to A 2 B or ABX spin systems.

show abstract

The Phosphazenes (Phosphonitrilic Compounds).

Cited by 178 publications

References 150 publications

Phosphonitrilic Compounds: Part I. The Mechanism of Phosphonitrilic Chloride Polymerization Capacitance, Conductance, and Electron-Spin Resonance Studies

Phosphonitrilic Compounds: Part I. The Mechanism of Phosphonitrilic Chloride Polymerization Capacitance, Conductance, and Electron-Spin Resonance Studies

Alternativ-Liganden, XIV [1]. Neue Chelatliganden des Typs (2-Me₂E′C₆H₄)Si(EMe₂)Me₂ (E, E′ = N, P, As; Me = CH₃) / Alternative Ligands, XIV [1]. Novel Chelating Ligands of the Type (2-Me₂E′C₆H₄)Si(EMe₂)Me₂ (E, E′ = N, P, As; Me = CH₃)

Structural and stereogenic properties of spiro- and ansa-substituted 1,3-propanedioxy derivatives of a spermine-bridged cyclotriphosphazene

Contact Info

Product

Resources

About

The Phosphazenes (Phosphonitrilic Compounds).

Cited by 178 publications

References 150 publications

Phosphonitrilic Compounds: Part I. The Mechanism of Phosphonitrilic Chloride Polymerization Capacitance, Conductance, and Electron-Spin Resonance Studies

Phosphonitrilic Compounds: Part I. The Mechanism of Phosphonitrilic Chloride Polymerization Capacitance, Conductance, and Electron-Spin Resonance Studies

Alternativ-Liganden, XIV [1]. Neue Chelatliganden des Typs (2-Me2E′C6H4)Si(EMe2)Me2 (E, E′ = N, P, As; Me = CH3) / Alternative Ligands, XIV [1]. Novel Chelating Ligands of the Type (2-Me2E′C6H4)Si(EMe2)Me2 (E, E′ = N, P, As; Me = CH3)

Structural and stereogenic properties of spiro- and ansa-substituted 1,3-propanedioxy derivatives of a spermine-bridged cyclotriphosphazene

Contact Info

Product

Resources

About

Alternativ-Liganden, XIV [1]. Neue Chelatliganden des Typs (2-Me₂E′C₆H₄)Si(EMe₂)Me₂ (E, E′ = N, P, As; Me = CH₃) / Alternative Ligands, XIV [1]. Novel Chelating Ligands of the Type (2-Me₂E′C₆H₄)Si(EMe₂)Me₂ (E, E′ = N, P, As; Me = CH₃)