Cyclophosphazene Metal Oxides, a New Class of Compounds, and Model Compounds for the Polymerization of Phosphazenes

Abstract

The acyclic, completely N‐silylated phosphazene 1 reacts with Re2O7 to form the first cyclophosphazene metal oxide 2 on elimination of siloxane. With 2,6‐diisopropylphenyl isocyanate, 2 is transformed into a mixture of novel cyclophosphazene metal imides. The formation of a twelve‐membered N6P4Re2 heterocycle in the process is particularly interesting, especially with regard to mechanistic aspects of the polymerization of phosphazenes.

Synthesis of Vanadium(III), -(IV), and -(V) Complexes That Contain the Pentafluorophenyl-Substituted Triamidoamine Ligand [(C6F5NCH2CH2)3N]3-

“…The two mechanisms for this reaction for which there is precedent in the literature are the “ureato mechanism” and the “metathesis mechanism” (eqs 5a and 5b, respectively). Isolated monomeric ureato complexes are relatively new, − although bridging ureato complexes have been known for some time . Addition of an aryl isocyanate to an oxo species gives an imido species via a similar VOCN metallacycle, presumably the intermediate in this analogous, well-known reaction.…”

Synthesis of Cyclo- and Polyphosphazenes with Pyridine Side Groups

“…Purification was carried out by column chromatography on aluminum oxide using dichloromethane/hexane mixtures as solvents. Recrystallization from dichloromethane/hexane and diethyl ether/hexane mixtures yielded the pure compound 2 as a dark yellow oil which crystallized slowly (1.8 Synthesis of [NP(OCH2CF3),(NH(CH2)2C5H4Ny" (3)(4)(5)(6). The syntheses of polymers 3-6 were carried out in a similar manner.…”

“…; Academic Press: New York, 1987; Vol. 8.48 (d, J = 5.4 Hz, 1 H, CHpyr), 7.30-6.0 (m, 26 H, Ar, CHpyl), 7.08 (t, J = 9.0 Hz, 1 H, CHpyl), 6.78 (d, J = 9.0 Hz, 1 H, CHpyr), 3.15 (b, 1 , NH), 3.10 (m, 2H, NHCtfj), 2.75 (t, 2H, NHCH2CH2, J = 7.5) 2 8.96 (d, J = 2.2 Hz, 1H, CHpyr), 7.96 (d of d, 7Chch = 9.3 Hz, Ichcch = 2.2 Hz, 1H, CHpyr), 7.40-6.80 (m, 25H, Ar ), 6.12 (b, NH), 6.02 (d, J = 8.3 Hz, 1H, CHpyr), 3.28 (d, J = 4 Hz, 1H, NH), 2.94 (m, 2H, NHCtfj), 2.71 (q, 2H, NHCH2CH2) " The molecular weight is higher than the calibration range.…”

Regioselective Substitution Reactions of Sulfur(VI)−Nitrogen−Phosphorus Rings: Reactions of the Halogenated Cyclic Thionylphosphazenes [NSOX(NPCl2)2] (X = Cl or F) with Oxygen-Based Nucleophiles

“…Inorganic heterocycles have attracted considerable attention because of their interesting structures, bonding, and reactivity, − their applications as precursors to or components of solid state materials, , and their use as precursors to novel polymers via ring-opening polymerization (ROP). − Over the past two decades six-membered cyclic thionylphosphazenes such as 1 have been well-studied, and the skeleton present in these compounds, which consists of four-coordinate sulfur(VI), nitrogen, and phosphorus atoms, has been shown to be robust and stable. , We recently reported that 1 and the fluorinated analogue 2 undergo thermal ROP to yield high molecular weight sulfur(VI)−nitrogen−phosphorus polymers, poly(thionylphosphazenes) ( 3 ), and macrocycles. ,, Reaction of 3 with aryloxide nucleophiles was found to yield moisture stable poly(aryloxythionylphosphazenes) 4 in which the sulfur−halogen bonds remain intact . In contrast, treatment of 3 with primary amines yielded poly(aminothionylphosphazenes) in which the halogen substituents at both phosphorus and at sulfur are replaced .…”