What absorbs at 964 cm⁻¹ in an FTIR spectrum?
A band near 964 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 964 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) | 7 | 6 | 1.0 |
| Alkyl C-H | 6 | 6 | 1.0 |
| C c single bond | 4 | 4 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| Silicon (Si) | 3 | 3 | 1.0 |
| Methoxy (OCH3) | 3 | 3 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| C-O single bond | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| Alkene (C=C) | 2 | 2 | 1.0 |
| Secondary amine | 2 | 2 | 1.0 |
| C n single bond | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Silanol (Si-OH) | 2 | 1 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 1.0 |
| Phosphorus | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| N c o | 1 | 1 | 1.0 |
| Silicon carbon | 1 | 1 | 1.0 |
| Nitride | 1 | 1 | 1.0 |
| Silicon nitrogen | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| Carbonate | 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 |
|---|---|---|---|
| Chitosan-Based | 964, 2924, 1743 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| PVC | 964, 834, 1195 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| asphalt | 964, 1600, 1376 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| Chitosan | 964, 1650, 1655 | Alkyl C-H, Hydroxyl (O-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 964 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
“964cm-1 different C-O O-H reflectance 1073, 1044, and and are assigned to and Indiana, USA) is gratefully acknowledged for vitrinite deformations in secondary alcohols (Table 2).”
Fossil cutin of Johnstonia coriacea (Corystospermaceae, Upper Triassic, Cacheuta, Argentina) DOI: 10.1016/j.coal.2018.02.016 -
C c single bond confidence 1.0
“The bands at 1255 and 964 cm-1 were ascribed to the C-C stretching and -CH2 vibration (Cl-C-H).”
Understanding Hydrothermal Dechlorination of PVC by Focusing on the Operating Conditions and Hydrochar Characteristics DOI: 10.3390/app7030256 -
Phosphate (PO4) confidence 1.0
“1,105 and 1,035 were assigned to the phosphate ions, and P-O cm-1 The infrared splitting factor (SF), also known as the the peak at 964 referred to the stretching mode of the phosphate crystallinity index or the crystallinity index, was bon”
Li 等 - 2023 - Fourier-transformed infrared spectroscopy study of DOI: 10.3389/feart.2022.1008139 -
Silicon (Si) confidence 1.0
“The peaks centred at 450 and 964 are attributed to Si-N stretching due to the silicon nitride.”
Optical and photoelectrochemical properties of nitrogen-doped a-SiC thin films deposited by reactive DOI: 10.1080/2374068X.2021.1890420 -
Amide confidence 1.0
“v3P-O and1-weekintraoralexposure.Thepeaksidentifiedwere:-OH (3500and1640cm(cid:2)1),-NH(3300-3100cm(cid:2)1),-CH 3/-CH 2-(2890, vibrations of amorphous Ca-P, and the peaks at 964 and 6101460cm(cid:2)1), (2052cm(cid:2)1), (1741cm(cid:2)1), 5”
Rahiotis 等 - 2008 - Characterization of oral films formed in the prese DOI: 10.1016/j.jdent.2008.01.005 -
Alkyl C-H confidence 1.0
“The most noticeable differences between both spectra are the disappearance of the bands showed by the precursor polymer that correspond to H 2O molecules trapped into the film and to the C-H stretch cm-1 of the saturated units in the polyel”
Almassio 等 - 2005 - Synthesis and characterization of poly(1,4-phenyle DOI: 10.1007/s00289-005-0377-2 -
Alkene (C=C) confidence 1.0
“Figure 6a shows the characteristic peaks of cm-1 (-CH bending), and 964 (C=C stretching band).”
Chitosan-Based Anti-Oxidation Delivery Nano-Platform: Applications in the Encapsulation of DHA-Enriched Fish Oil DOI: 10.3390/md19080470 -
Alkyl C-H confidence 1.0
“S=O 1024 stretching vibration 964 Trans-C-H wagging vibration (butadiene block) 940 C-H deformation vibration of ring hydrogens 848”
Effect of Phenolic Resin on the Rheological and Morphological Characteristics of Styrene-Butadiene Rubber-Modified Asphalt DOI: 10.3390/ma13245836
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