What absorbs at 3544 cm⁻¹ in an FTIR spectrum?
A band near 3544 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 4 cited sources
Quick answer
A band near 3544 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 |
|---|---|---|---|
| Silicon (Si) | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
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 3544 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
“LLM confirmed rule peak-group candidate”
Optimizing Procedures of Ultrasound-Assisted Extraction of Waste Orange Peels by Response Surface Methodology DOI: 10.3390/molecules27072268 -
Silicon (Si) confidence 1.0
“All {Cr(cid:113)(cid:113) Where core spectra showed zero or near-zero absorbance -(2H)(cid:48)(cid:48) Si}× interface spectra show peaks due to (3544,”
Jollands 等 - 2021 - A combined Fourier transform infrared and Cr K-edg DOI: 10.5194/ejm-33-113-2021 -
Hydroxyl (O-H) confidence 1.0
“itswerechosenatthesamewavenumbervalues,from∼3705 2880cm-1 ∼3702 The appearance of interference fringes in spectra can be useto for OH bands of quartz grains and to 3544cm-1 ful to determine the optical path length in thin samples, as for OH”
Kronenberg 等 - 2017 - Synchrotron FTIR imaging of OH in quartz mylonites DOI: 10.5194/se-8-1025-2017 -
Silicon (Si) confidence 1.0
“The gradual growing of these features is accompanied in the whole range (see cm-1, Fig S1 in SI) by the corresponding evolution of the (b) and (c) OH groups (3670 and 3544 cm-1).”
Negri 等 - 2018 - Investigating the Low Temperature Formation of Cu- DOI: 10.1002/chem.201802769
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