What absorbs at 1040 cm⁻¹ in an FTIR spectrum?
A band near 1040 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 1040 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 |
|---|---|---|---|
| C-O single bond | 34 | 32 | 1.0 |
| Methoxy (OCH3) | 32 | 30 | 1.0 |
| Methacrylate | 32 | 30 | 1.0 |
| Acetate | 32 | 30 | 1.0 |
| Silicon-oxygen (Si-O) | 14 | 13 | 1.0 |
| Alkyl C-H | 10 | 10 | 1.0 |
| Phosphate (PO4) | 9 | 7 | 1.0 |
| Amide | 8 | 6 | 1.0 |
| Hydroxyl (O-H) | 7 | 6 | 1.0 |
| Silicon (Si) | 7 | 5 | 1.0 |
| C c single bond | 6 | 5 | 1.0 |
| Carbohydrate | 4 | 4 | 1.0 |
| Siloxane (Si-O-Si) | 4 | 4 | 1.0 |
| Secondary amine | 4 | 3 | 1.0 |
| C n single bond | 4 | 3 | 1.0 |
| Phosphorus | 4 | 2 | 1.0 |
| N h | 3 | 3 | 1.0 |
| Sulfonate | 2 | 1 | 1.0 |
| Silanol (Si-OH) | 2 | 1 | 1.0 |
| Thiocarbonyl | 1 | 1 | 1.0 |
| Silicate | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Silicon carbon | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Lignin | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
| Silicon nitrogen | 1 | 1 | 1.0 |
| Boron nitrogen | 1 | 1 | 1.0 |
| Nucleic acid | 1 | 1 | 0.9 |
| Aromatic ring | 1 | 1 | 0.9 |
| Borate | 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 |
|---|---|---|---|
| MWCNTs | 1040, 3396, 1735 | Methacrylate, Acetate, C-O single bond | 1 |
| nanotubes | 1040, 1735, 1630 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| silver nanoparticles | 1040, 1636, 1631 | Methacrylate, Acetate, C-O single bond | 1 |
| protein | 1040, 1650, 1640 | 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 1040 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
-
Boron nitrogen confidence 1.0
“The films contained mixed phases of h-BN cm(cid:1)1 peak at 1040 and c-BN, which were confirmed from XRD, TEM, SIMS, for the B-N stretching mode of c-BN XPS, and FTIR studies.”
Chowdhury 等 - 2004 - Novel electrodeposition route for the synthesis of DOI: 10.1016/j.matlet.2004.05.079 -
Acetate confidence 1.0
“1172 C-O stretching 1040 1040 C-O stretching 1250 - 1010/1150 ± 15 1157”
Differentiation between copal and amber by their structure and thermal behaviour DOI: 10.1007/s10973-023-12333-8 -
C-O single bond confidence 1.0
“In addition, a cm-1, small peak appears at 1040 which can be associated with R-O-R ether functionalities, for H Fig.”
Goyanes 等 - 2007 - Carboxylation treatment of multiwalled carbon nano DOI: 10.1016/j.diamond.2006.08.021 -
Silicon nitrogen confidence 1.0
“2(cid:3)1019 [15] Si-N Si-N local distorted 790 stretching 2(cid:3)1019 Si-N N-Si3 asymmetric stretching 850 [15] 2(cid:3)1019 950 [15] Si-N Si-N stretching of H-SiN3 Si-O Si-O symmetric stretching 1040 - [2,16]”
Effect of PECVD silicon oxynitride film composition on the surface passivation of silicon wafers DOI: 10.1016/j.solmat.2011.09.052 -
Alkyl C-H confidence 1.0
“The spectrum shows also two bands at 1263cm(cid:2)1, C-H C-O 1369 and owing to bending of cellulose and the stretching vibration 1040cm(cid:2)1”
Alkali and epoxy-silane surface modified pine cone flour reinforced polypropylene/poly (lactic acid) DOI: 10.1080/01694243.2021.1952677 -
Acetate confidence 1.0
“22 and 1121 Therefore, both FTIR-ATR and Raman spectroscopy PCA emphasised peaks at 1040 C-O/C-C/C-N found changes in peak intensities and wavenumbers within the sugar region cm-1).”
Mcavan 等 - 2020 - Quantification of protein glycation using vibratio DOI: 10.1039/c9an02318f -
Alkyl C-H confidence 1.0
“Since the molecule stitutedtoluenes.Thepeaksat1390,1290,1210,1205,1170,1120, 1040cm-1 do not possess any rotational, reflection or inversion symmetry, 1110, are occurring due to the effect of C-H in plane the molecule is considered under Cs”
Nagabalalsubramanian 等 - 2009 - A scaled quantum mechanical approach of vibrationa DOI: 10.1016/j.saa.2009.10.002 -
Hydroxyl (O-H) confidence 1.0
“The AgNPs was characterized with FTIR peaks around 3280, 1620, 1400 and 1040 cm-1 C-O-H assigned to O-H, C=O, and C-C groups respectively, as possible stabilizing and Staphylococcus capping groups.”
Ogunsile 等 - 2020 - Green synthesis of silver nanoparticles from leaf DOI: 10.1088/1757-899X/805/1/012032
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