• Top library match: propan-2-yl nitrate #370

• The library top match propan-2-yl nitrate is very weak (similarity 0.0, 15% confidence), and characteristic nitrate ester bands (e.g., N-O stretch near 860 cm-1) are absent from the sample spectrum, making this specific identification unsupported.
• The C-N assignment at 754 cm-1 originates from a study on mineral‑doped silica gel, and its direct relevance to an organic‑matrix sample is uncertain.
• The analogical literature evidence for C-N stretching at 1280 cm-1 from cross‑linked PVA hybrid membranes is only suggestive and cannot be taken as a definitive assignment.
• Many of the cited literature sources deal with materials (polymers, nanoparticles, biological extracts, mineral composites) that may differ significantly from the composition of the current sample, reducing the transferable certainty of the peak assignments.
• The exact nature of the unsaturation (aliphatic C=C vs. aromatic ring) cannot be determined without additional characteristic bands, such as aromatic C-H stretches above 3000 cm-1 or ring‑breathing modes in the 1450–1600 cm-1 region.

Recommended next steps: To reduce the present uncertainty, obtain a higher‑resolution spectrum, especially in the fingerprint region (400–1500 cm-1), to search for weaker but structurally indicative bands. Complementary analysis by mass spectrometry or nuclear magnetic resonance spectroscopy is recommended to confirm the presence of nitrogen and to resolve whether the unsaturation is olefinic or aromatic. If the sample is a known reaction product or mixture, comparison with a verified reference standard of the suspected compound would greatly improve the reliability of the peak assignments.