Polymers with Sulfur(VI)−Nitrogen−Phosphorus Backbones:  Synthesis, Characterization, and Properties of Fluoroalkoxy-Substituted Poly(thionylphosphazenes)

Abstract

Reaction of the halogenated poly(thionylphosphazene) [NSOCl(NPCl2)2] n (2a), which possesses a novel S(VI)−N−P backbone, with 2, 3, and 4 equiv of Na[OCH2CF3], followed by excess nBuNH2, afforded mixed-substituent poly[alkoxy(amino)thionylphosphazenes] [NSO(NHnBu)(NPR2)2] n (6) (a, R = 51% OCH2CF3, 49% NHnBu; b, R = 76% OCH2CF3, 24% NHnBu; c, R = 95% OCH2CF3, 5% NHnBu) in which the polymers were regioselectively substituted with trifluoroethoxy substituents only at phosphorus and not at sulfur. The resulting moisture stable polymers were structurally characterized by 31P, 1H, 13C, and 19F NMR spectroscopy. Molecular weights were in the range M w = 3.3 × 104 to 1.4 × 105 and M n = 1.9 × 104 to 8.2 × 104 according to GPC analysis in THF versus polystyrene standards. The thermal transition behavior was investigated by DSC, glass transition temperatures (T g's) ranged from −30 to −14 °C, and no melt transitions were detected. Analysis of these new polymers by TGA showed that they were stable to weight loss up to ca. 250 °C under nitrogen at a heating rate of 10 °C/min.

Polymers with Sulfur(VI)−Nitrogen−Phosphorus Backbones: Synthesis, Characterization, and Properties of Poly[(dialkylamino)thionylphosphazenes]

“…The perhalogenated ring-opened polymers 2a and 2b are moisture-sensitive. However, we have previously described in detail the synthesis and properties of air-stable poly(thionylphosphazenes) 3 , 4 , and 5 , substituted with sodium aryloxides Na[OAr], sodium alkoxides Na[OCH 2 CF 3 ], or primary amines RNH 2 . Poly(thionylphosphazenes) show interesting properties different from polyphosphazenes and poly(oxothiazenes) concerning polymer morphology, thermal transition behavior, reactivity patterns, and the types of polymer structures accessible .…”

The Preparation of New Polystyrenic Onium and Substituted Poly(Thionylphosphazene) Antimicrobials

“…While there have been various studies focused on the substitution reactions of poly(thionylphosphazenes), 76,89,90 polymerization reactions of thionylphosphazenes postsubstitution have not been explored. Ideally, being able to substitute thionylphosphazenes and then polymerize them would allow for a more controlled loading and ensure complete substitution, which would also be beneficial for the antimicrobial studies.…”

The Preparation of New Polystyrenic Onium and Substituted Poly(Thionylphosphazene) Antimicrobials

“…One class of heterophosphazenes that is of interest is the thionylphosphazene, which is a derivative of the thiophosphazene and consists of a sulfur(VI) nitrogen phosphorus backbone. 76 The first reported synthetic routes to thionylphosphazenes were substituted thionylphosphazenes with various oxygen-based nucleophiles, they discovered the reaction pattern to be PCl2 > PCl(OR) > SOX, showing preferential substitution at the phosphorus sites prior to moving on to the sulfur site. 83 A similar pattern of PCl2 > PCl(NHR) > SOCl has also been observed with some primary amines by van de Grampel and coworkers.…”