What absorbs at 3530 cm⁻¹ in an FTIR spectrum?
A band near 3530 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 8 cited sources
Quick answer
A band near 3530 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 |
|---|---|---|---|
| Hydroxyl (O-H) | 5 | 4 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Metal hydroxyl | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 0.7 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| polyurethane | 3530, 2270, 1700 | N h | 1 |
| calcite | 3530, 2850, 2864 | Hydroxyl (O-H) | 1 |
| polymer | 3530, 1718, 1722 | Hydroxyl (O-H) | 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 3530 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
-
Metal hydroxyl confidence 1.0
“In Gibbsite, peak appears around 3530 and the peak in Al-OH Zn-OH”
Dependence of bonding interactions in Layered Double Hydroxides on metal cation chemistry DOI: 10.1016/j.molstruc.2016.06.045 -
Hydroxyl (O-H) confidence 1.0
“FTIRspectrumofthebluelayercomparedwithlapislazuliblue FIGURE 8 characteristic bands of calcite, due to the fresco technique - pigment andcalcite references 3554cm-1 the following principal bands arise: 3530, (O-H 971cm-1 stretching);”
Zorba 等 - 2006 - Technique and palette of XIIIth century painting i DOI: 10.1007/s00339-006-3548-6 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Cortea 等 - 2020 - Uncovering hidden jewels an investigation of the DOI: 10.1186/s40494-020-00401-3 -
Hydroxyl (O-H) confidence 1.0
“LLM confirmed rule peak-group candidate”
Dynamic Mechanical Properties and Thermal Properties of Longitudinal Basalt/Woven Glass Fiber Reinforced Unsaturated Polyester Hybrid Composites DOI: 10.3390/polym13193343 -
Metal oxygen confidence 1.0
“C-H vibration 1185, 816, 759, 577 1135, 116, 1054, 675, 638, 434, 242 Si-O and M-O stretching/bending five enhanced overtone of the H assignment of the resulting bands (at 3530, 3453, 3385, 2O bending mode.”
Lacalamita - 2018 - Micro-FTIR and EPMA Characterisation of Charoite f DOI: 10.1155/2018/9293637 -
confidence 1.0
“Controlled Drug Delivery: Fundamentals & Applications, 3530.06cm-1 wave numbers of (N-H stretching), New York: Marcel Dekker;”
Shirisha 等 - 2017 - Preparation and Evaluation of Matrix Type Transder DOI: 10.5530/ijper.51.4.80 -
Hydroxyl (O-H) confidence 0.9
“Observed band at 3530 cm-1 in clinopyroxene.”
Temperature dependence of IR absorption of OH species in clinopyroxene DOI: 10.2138/am.2010.3501 -
Carbonyl (C=O) confidence 0.7
“Shoulder around 3530 cm-1 assigned to C=O vibration.”
Shukla 等 - 2019 - Chemical and Application Properties of Some Solven DOI: 10.5552/drvind.2019.1809
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