• Top library match: Poly(diphenoxyphosphazene) #1597

1. The FTIR spectrum is most consistent with an aromatic phosphate/ester material, likely a poly(diphenoxyphosphazene) polymer or a closely related phosphazene derivative. The spectrum displays bands characteristic of aromatic rings (1603, 1507 cm⁻¹), phenoxy C–O stretching (1238, 1160 cm⁻¹), and phosphate P–O–C vibration (914 cm⁻¹) [4]. Aliphatic C–H stretching and bending modes (714, 1429, 1475 cm⁻¹) are also present, together with C–O single bond absorptions that resemble those of polysaccharides, indicating significant oxygen content and raising the possibility of C-O‑formulated components or a mixed composition.

• The analogical excipient pattern (polysaccharide/sugar alcohol) conflicts with a pure polyphosphazene assignment; the bands at 1043 cm⁻¹ [2] and 1116 cm⁻¹ appear typical of carbohydrate ring vibrations rather than a phosphazene backbone, pointing toward possible C-O‑formulated additives or a different family of oxygen‑rich polymers.
• The direct literature assignment of 753 cm⁻¹ to a sulfur heterocycle [3] is not expected in poly(diphenoxyphosphazene); this assignment likely originates from a chemically dissimilar system and should not be over‑interpreted.
• The exact material identity cannot be confirmed with high confidence because the library similarity is moderate (0.74) and some prominent bands are more reminiscent of polysaccharide/sugar alcohol excipients than of a phosphazene polymer.
• The absence of clear P=N stretching markers in the typical 1200–1300 cm⁻¹ region, or their overlap with strong C–O bands, prevents a definitive spectroscopic verification of the phosphazene backbone.
• The heterogeneity of the direct and analogical literature sources (covering excipient mixtures, catalysts, natural products) reduces the specificity of the peak assignments.

Recommended next steps: Confirm the presence of phosphorus and nitrogen by elemental analysis or X‑ray photoelectron spectroscopy to directly support the phosphazene framework. Compare the spectrum with a reference database of pure poly(diphenoxyphosphazene) measured under identical conditions, and perform spectral subtraction if excipient bands are suspected. If the sample is a pharmaceutical formulation, extract the active material or use thermogravimetric analysis to assess organic/inorganic content and identify potential carbohydrate diluents.