What absorbs at 960 cm⁻¹ in an FTIR spectrum?
A band near 960 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 960 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 |
|---|---|---|---|
| Phosphate (PO4) | 24 | 23 | 1.0 |
| Silicon-oxygen (Si-O) | 16 | 13 | 1.0 |
| Silanol (Si-OH) | 14 | 13 | 1.0 |
| Silicon (Si) | 13 | 10 | 1.0 |
| Hydroxyl (O-H) | 11 | 10 | 1.0 |
| Alkyl C-H | 8 | 8 | 1.0 |
| Siloxane (Si-O-Si) | 5 | 5 | 1.0 |
| Phosphorus | 5 | 5 | 1.0 |
| Metal oxygen | 3 | 3 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| Carboxyl (COOH) | 3 | 3 | 1.0 |
| Amide | 3 | 3 | 1.0 |
| C-S single bond | 2 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Ketone | 2 | 2 | 1.0 |
| Ester | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| Borate | 2 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Sulfate (SO4) | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Amine primary | 1 | 1 | 1.0 |
| Ammonium | 1 | 1 | 1.0 |
| Quaternary ammonium | 1 | 1 | 1.0 |
| Silicate | 1 | 1 | 1.0 |
| Styrene | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Silicon carbon | 1 | 1 | 1.0 |
| Thiocarbonyl | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed 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 960 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
-
Phosphate (PO4) confidence 1.0
“cm-1 Additional peaks were found in both models at 1,062, 1,053, 1,047, 1,040, and 1,029 b cm-1) cm-1 m The peak width range was restricted to the width of the sample's phosphate peak (at 960 ± 2 1 c Chi-squared is the weighted difference b”
Awonusi 等 - 2007 - Carbonate assignment and calibration in the raman DOI: 10.1007/s00223-007-9034-0 -
Phosphate (PO4) confidence 1.0
“5 highlights that the first two IR bands, assigned to the cm-1 cm-1, Mo-O-Mo vibrational modes, are up-shifted from 792 and 870 to 800 and 887 while the last two IR cm-1 Mo=O bands attributed to the and P-O vibrational modes are down-shifte”
Baibarac 等 - 2019 - Adsorption of 1,4-phenylene diisothiocyanate onto DOI: 10.1038/s41598-019-48314-x -
Amide confidence 1.0
“C-C p coupling of ligands to specific platelets receptors, leading of < 0.05) are related to stretching vibrations in cm-1) intra-cellular extra-cellular signaling,[43] and the amide I band it is to and carbon chains of lipids (960 cm-1).”
Analysis of platelets in hypertensive and normotensive individuals using Raman and Fourier transform infrared‐attenuated total reflectance spectroscopies DOI: 10.1002/jrs.5540 -
C-S single bond confidence 1.0
“This in situ method is performed by the direct and stoim The presence of (C---S) absorption bands located at 960-”
Haezam 等 - 2021 - Synthesis and cytotoxic activity of organotin(IV) DOI: 10.1016/j.sjbs.2021.02.060 -
Phosphate (PO4) confidence 1.0
“LLM confirmed rule peak-group candidate”
Jaber 和 Kovacs - 2019 - Preparation and synthesis of hydroxyapatite bio-ce DOI: 10.14382/epitoanyag-jsbcm.2019.18 -
Metal oxygen confidence 1.0
“For the TiO loaded SBA-15 photocatalysts, the IR 2 cm-1 ∼960 absorption at is commonly accepted as the characteristic vibration of the Ti-O-Si bond.”
Synthesis of TiO<sub>2</sub> Supported on SBA-15 Using Chelating Method and Their Photocatalytic Decomposition of Methylene Blue DOI: 10.1166/jnn.2011.3207 -
Acetate confidence 1.0
“Negative, Artefact ≅920+1037 1970 SiO2 combination band or 970+1000 [60] C=O stretching shoulder Negative, Artefact ≅960+1000 combination band 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 -
Silicon (Si) confidence 1.0
“cm¡1 A frequency at about 960 was to a vibration at 960 reported as well in HCl-treated palygorskite and assigned to a Si-OH vibration (12).”
Modification of Chrysotile Surface by Organosilanes: An IR–Photoacoustic Spectroscopy Study DOI: 10.1006/jcis.2001.7524
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