What absorbs at 3577 cm⁻¹ in an FTIR spectrum?
A band near 3577 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 3 cited sources
Quick answer
A band near 3577 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Phosphorus | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Bromine | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| Hydroxyapatite | 3577, 1620, 1639 | Phosphate (PO4), Phosphorus | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 3577 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Literature behind these assignments
-
Hydroxyl (O-H) confidence 1.0
“O-H Two water stretching bands of BR at 3607 and 3577 cm-1 seen in the L minus BR difference spectrum are affected by mutation of Thr46 (27, 36).”
Maeda 等 - 1999 - Chromophore-protein-water interactions in the L in DOI: 10.1021/bi9907072 -
Phosphate (PO4) confidence 1.0
“bands: 3577 and 632 An absorption spectrum showed that the phosphate group was”
Alshemary 等 - 2023 - Microstructure analysis and thermal stability of M DOI: 10.15251/DJNB.2023.181.1 -
confidence 0.9
“Text states 'integrated absorption of the 3577 line' and 'local vibrational mode of an OH molecule adjacent to a Li atom'.”
Johansen 等 - 2011 - Li and OH-Li Complexes in Hydrothermally Grown Sin DOI: 10.1007/s11664-010-1404-0
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