LINEAR SHORT-CHAIN CHLOROPHOSPHAZENES. SYNTHESES, ³¹P, ¹⁵N-NMR AND RAMAN SCATTERING CHARACTERIZATIONS

Abstract

Two classes of short-chain linear chlorophosphazenes have been synthesized in high degree of purity, Cl₃PN(PCl₂N) _n P(X)Cl₂ (X = 0, n = 0, 1, 2, 3; X = S, n = 0, 1) and [Cl₃PN(PCl₂N)nPCl₃] [Y] (Y = Cl⁻, n = 0,1; Y = PCI⁻ ₆ n = 0, 1,2). New routes of synthesis were employed for some compounds. All these molecular and ionic compounds were characterized by ³¹P, ¹⁵N-NMR and Raman scattering at room temperature. A ³¹P-NMR study of the molecular compounds Cl₃PN(PCl₂N)nP(X)Cl₂ as a function of temperature shows a coalescence phenomenon near 220K for two compounds, Cl₃PN(PCl₂N)₂P(O)Cl₂ and Cl₃PN(PCl₂N)₃P(O)Cl₂ demonstrating the flexibility of the PN backbone. The Raman scattering provides evidence for planar cis-trans molecular conformation in the melt and in the solution as well as in the solid state for all the molecular compounds.

Key Words:

• Chlorophosphazenes
• ³¹P-NMR
• ¹⁵N-NMR
• Raman scattering