What absorbs at 950 cm⁻¹ in an FTIR spectrum?
A band near 950 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 950 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) | 21 | 17 | 1.0 |
| Alkyl C-H | 20 | 16 | 1.0 |
| Silicon-oxygen (Si-O) | 15 | 14 | 1.0 |
| Silicon (Si) | 14 | 13 | 1.0 |
| Silanol (Si-OH) | 10 | 8 | 1.0 |
| Methoxy (OCH3) | 9 | 9 | 1.0 |
| Methacrylate | 9 | 9 | 1.0 |
| C-O single bond | 9 | 9 | 1.0 |
| Acetate | 9 | 9 | 1.0 |
| Carbohydrate | 7 | 7 | 1.0 |
| Secondary amine | 6 | 6 | 1.0 |
| Alkene (C=C) | 6 | 5 | 1.0 |
| C n single bond | 4 | 4 | 1.0 |
| Amide | 4 | 4 | 1.0 |
| Phosphate (PO4) | 4 | 4 | 1.0 |
| Carboxyl (COOH) | 4 | 3 | 1.0 |
| N h | 3 | 3 | 1.0 |
| Aromatic ring | 3 | 3 | 1.0 |
| C c single bond | 3 | 3 | 1.0 |
| Silicon carbon | 2 | 2 | 1.0 |
| Metal oxygen | 2 | 1 | 1.0 |
| Silicate | 1 | 1 | 1.0 |
| Nitrate | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Metal hydroxyl | 1 | 1 | 0.9 |
| Metal oxo | 1 | 1 | 0.9 |
| Nucleic acid | 1 | 1 | 0.8 |
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 | 950, 1100, 1080 | Silicon-oxygen (Si-O), Silicon (Si), Hydroxyl (O-H) | 1 |
| STARCH | 950, 1650, 1540 | Hydroxyl (O-H), Alkyl C-H | 1 |
| HAp | 950, 3572, 917 | Hydroxyl (O-H), 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 950 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
“Sharp peak at 520 cm-1 with two wide bands around 480 and 950 cm-1 assigned to a-Si and SiN modes respectively [25].”
Benyahia 等 - 2017 - Evolution of Optical and Structural Properties of DOI: 10.4028/www.scientific.net/JNanoR.49.163 -
confidence 1.0
“564.84 903.0 651.13 Si-O vibration 949.7 204.84 924.4 171.65 947.4”
Theoretical and experimental study of structures and properties of cement paste The nanostructural aspects of C–S–H DOI: 10.1016/j.jpcs.2011.05.001 -
Hydroxyl (O-H) confidence 1.0
“These values being 28 As is well known, OH bending vibrations occur between 950cm-1, and 42%, respectively, in the Mg-rich palygorskite.”
Cai 等 - 2007 - A Fourier transform infrared spectroscopic study o DOI: 10.1016/j.saa.2006.02.053 -
Silanol (Si-OH) confidence 1.0
“dense spherical silica powders were separated and settled down shows the presence of silanol (Si-OH) vibrations at 950 after about 600 s.”
De 等 - 2000 - Hydrolysis-condensation reactions of TEOS in the p DOI: 10.1039/B003221M -
N h confidence 1.0
“The main characteristic Raman signals include N-O signals in FTIR were correlated to NH and ClO cm(cid:1)1, 660symmetric stretch at 950 NH and NH wagging asymmetric stretch;”
Elbasuney 和 El-Sherif - 2017 - Instant detection and identification of concealed DOI: 10.1016/j.forsciint.2016.11.036 -
Acetate confidence 1.0
“Characteristic peaks were observed at cm-1 cm-1 1350 (C-O stretching) and 950 (C-O-C bending).”
Felipe Tirado 等 - 2017 - EVALUATION OF THE COAGULANT CAPACITY OF STARCH OBT DOI: 10.20937/RICA.2017.33.esp01.11 -
Phosphate (PO4) confidence 1.0
“tite at 950 °C due to the founding peaks corresponding to phosphate (632 and hydroxyl (3572 XRD analysis confirmed the formation of HAp at 950 °C by the presence three main peaks: (211), (112), and (300), which correspond to the characteris”
Effect of calcination temperature on characterization of natural hydroxyapatite prepared from carp fish bones DOI: 10.1007/s42452-019-0396-5 -
Ring structure confidence 1.0
“The cm-1 increase in the peak intensity at 950 is due to Figure 5 SEM images of kafirin nanofibers loaded with aC-H the contribution of ring in thymol.”
Fabrication of pristine electrospun kafirin nanofiber mats loaded with thymol and carvacrol DOI: 10.1007/s10853-020-05663-7
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.