What absorbs at 970 cm⁻¹ in an FTIR spectrum?
A band near 970 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 970 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) | 11 | 10 | 1.0 |
| Alkyl C-H | 10 | 9 | 1.0 |
| Methacrylate | 9 | 8 | 1.0 |
| Acetate | 9 | 8 | 1.0 |
| Silicon (Si) | 8 | 8 | 1.0 |
| Silicon-oxygen (Si-O) | 8 | 6 | 1.0 |
| Silanol (Si-OH) | 7 | 6 | 1.0 |
| Methoxy (OCH3) | 7 | 6 | 1.0 |
| Alkene (C=C) | 6 | 5 | 1.0 |
| C-O single bond | 6 | 5 | 1.0 |
| Protein | 5 | 5 | 1.0 |
| Phosphate (PO4) | 5 | 5 | 1.0 |
| C c single bond | 5 | 4 | 1.0 |
| Phosphorus | 3 | 3 | 1.0 |
| Carbonyl (C=O) | 3 | 3 | 1.0 |
| Nucleic acid | 3 | 2 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Ketone | 2 | 2 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Methyl | 2 | 2 | 1.0 |
| C-S single bond | 2 | 2 | 1.0 |
| Thiol | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Metal oxygen | 2 | 1 | 1.0 |
| Ring structure | 2 | 1 | 1.0 |
| Oxygen heterocycle | 2 | 0 | 1.0 |
| Fluorine (C-F) | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Fatty acid | 1 | 1 | 1.0 |
| Bromine | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Metal hydroxyl | 1 | 0 | 1.0 |
| Silicon carbon | 1 | 0 | 1.0 |
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 |
|---|---|---|---|
| silica | 970, 1100, 1080 | Hydroxyl (O-H), Alkyl C-H, Methacrylate | 1 |
| DNA | 970, 1712, 1660 | Methacrylate, Acetate | 1 |
| cells | 970, 1741, 1020 | Alkyl C-H, Methacrylate, Acetate | 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 970 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
-
Silicon (Si) confidence 1.0
“The presence (SiO)n-, of siloxane groups, attached to the inorganic polymer 1000-1100cm-1 appears as an intense band in the region, with a 970cm-1, which was assigned to the Si O H bending shoulder at frequency.”
Dey 等 - 2008 - Mesoporous silica functionalized with diethylenetr DOI: 10.1016/j.colsurfa.2008.03.030 -
C c single bond confidence 1.0
“In addition, the peak at 970 is attributed to the deoxyribose C-C stretching mode, and it is often used as an internal reference for normalization to lyze the structural changes of dsDNA [34,46].”
Assessing B-Z DNA Transitions in Solutions via Infrared Spectroscopy DOI: 10.3390/biom13060964 -
confidence 1.0
“and symmetric vibration of Si-O-Si bonds at InfraUnmodified 10-15 nanosilica 970cm-1 red analysis of the nanosilica shows a peak around PFOA-modified 170-250 nanosilica”
Ganie 等 - 2020 - Synthesis and Characterization of a New Surface-Mo DOI: 10.1155/2020/8814260 -
Thiol confidence 1.0
“In Fig.1(a) , compared to the spectra of C-S-H, the spectra of C-A-S-H shows much stronger peaks at 970cm-1 cm-1, and 470 which indicates that bridging oxygen numbers and SiO tetrahedral about 4 chain length increases in C-A-S-H respectivel”
He 等 - 2011 - Morphology and Structure of Aluminum Substituted C DOI: 10.4028/www.scientific.net/AMR.287-290.1193 -
Acetate confidence 1.0
“Absent ≅ 2000 SiO2 overtone 2×1000 C=O stretching Medium Negative, Artefact ≅920+1037 1970 SiO2 combination band or 970+1000 [60] C=O stretching”
FTIR photoacoustic spectroscopy for identification and assessment of soil components_ Chernozems and their size fractions DOI: 10.1016/j.pacs.2020.100162 -
C c single bond confidence 1.0
“All the spectra examined consist of typical absorption peaks at about 3300 cm-l by (OH stretching), 3295 cm-' ( h C - H stretching), 2950 cm-l (C-H stretching), Downloaded 2255 cm-l (C%C-hC stretching), 2120 cm-l (C%C stretching), 1360-1300”
LANGER 和 MOSS - 1993 - FTIR STUDIES OF TRIMETHYLENE LINKED BIS-DIACETYLEN DOI: 10.1080/10587259308030157 -
Acetate confidence 1.0
“correlation with wavenumber values attributed to vibrations of (∼970cm-1), C-O DNA base-sugar bonds We have shown that FTIR spectroscopy is a sensitive technique furanose stretching cm-1) cm-1).”
A new approach to studying the effects of ionising radiation on single cells using FTIR synchrotron microspectroscopy DOI: 10.1016/j.radphyschem.2013.03.037 -
Silanol (Si-OH) confidence 1.0
“wavenumber range It is seen that the absorption That is, the absorption peaks at wavenumbers of 1434 and 1089cm(cid:1)1, peaks at wavenumbers of 970 and which are assigned 3452cm(cid:1)1 represent silanol groups (Wagner, 1976).”
Novel epoxidized natural rubber composites with geopolymers from fly ash waste DOI: 10.1016/j.wasman.2019.02.013
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