What absorbs at 958 cm⁻¹ in an FTIR spectrum?
A band near 958 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 958 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 |
|---|---|---|---|
| Alkyl C-H | 3 | 3 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 0.9 |
| N-O bond | 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 |
|---|---|---|---|
| asphalt | 958, 1600, 1376 | Alkyl C-H, Aromatic ring, Alkene (C=C) | 1 |
| PVC | 958, 834, 1195 | Alkyl C-H | 1 |
| PVDF | 958, 1160, 840 | Alkyl C-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 958 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
-
Alkyl C-H confidence 1.0
“Trans -CH and cis -CH wagging modes may be seen at 958 and 614 cm-1 respectively.”
Ramadan 和 Ismail - 2022 - Tunning the Physical Properties of PVDFPVCZinc F DOI: 10.21203/rs.3.rs-935328/v1 -
C-S single bond confidence 1.0
“In the spectrum of the leaf part of the plant,1st peak (3372.57 cm-1) belongs to OH group in the group of (COOH), 2nd peak (2916.72-2848.93 cm-1, doublet) belongs to the group of NH 2, 3rd peak (1734.36 cm-1) belongs to C=O group in the gro”
Tasci 等 - 2016 - Determination of alliin and allicin in the plant o DOI: 10.17660/ActaHortic.2016.1143.19 -
Acetate confidence 1.0
“Dibutyltin Maleate (DBTM, I) The FT-IR spectrum of dibutyltin maleate (DBTM, I) showed characteristic peaks at: 2,854, 2,868, cm-1 cm-1 assigned to C-H stretching (-CH 2CH 2CH 2CH 3, and -CH=CH-), 1,615 2,926, and 2,958 cm-1 1H-NMR assigned”
Synthesis and Characterization of Organotin Containing Copolymers: Reactivity Ratio Studies DOI: 10.3390/molecules15031784 -
confidence 1.0
“Si-O-C, Si-O in APTES 3 958cm1 and Si-O-C 2H contribute to bands centred at 1110, 1065 and [33, 34, 36, 38].”
Interaction of (3-Aminopropyl)triethoxysilane With Late Ar-N 2 Afterglow: Application to Nanoparticles Synthesis DOI: 10.1002/ppap.201500201 -
Phosphate (PO4) confidence 1.0
“In addition, the spectra of ImTMSP present a P-O-Si vibrations are present only for ImPE at 1042 and 958 cm-1 [28,37].”
Design of Phosphonated Imidazolium-Based Ionic Liquids Grafted on -Alumina: Potential Model for Hybrid Membranes DOI: 10.3390/ijms17081212 -
Alkyl C-H confidence 1.0
“The peaks at 958, 816 and 749 were ~99.0%), and absolute alcohol (C 2H 5OH) purchased from related to the bending vibrations of C-H in phenyl.”
Sembiring 等 - 2019 - DOI: 10.1590/0366-69132019653742497 -
Alkene (C=C) confidence 1.0
“allyl and amine is suggested by the disappearance in the films of the stretching vibrations of the chemical reaction between allyl and amine is suggested by the disappearance in the films of the unsaturated C=C bond at 1642 cm-1 and the ben”
Preparation and Chemical/Microstructural Characterization of Azacrown Ether-Crosslinked Chitosan Films DOI: 10.3390/ma10040400 -
Alkyl C-H confidence 1.0
“The absorption peak located cm-1 near 958 corresponds to cis CH wagging and trans CH wagging mode of PVC respectively.”
Arya 和 Sharma - 2018 - Structural, microstructural and electrochemical pr DOI: 10.1007/s11581-017-2364-7).
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