What absorbs at 1025 cm⁻¹ in an FTIR spectrum?
A band near 1025 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 1025 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 | 29 | 27 | 1.0 |
| Methoxy (OCH3) | 23 | 22 | 1.0 |
| Methacrylate | 23 | 22 | 1.0 |
| Acetate | 23 | 22 | 1.0 |
| Hydroxyl (O-H) | 7 | 6 | 1.0 |
| Carbohydrate | 5 | 5 | 1.0 |
| Phosphate (PO4) | 4 | 4 | 1.0 |
| Alkyl C-H | 4 | 4 | 1.0 |
| Phosphorus | 3 | 3 | 1.0 |
| Silicon-oxygen (Si-O) | 3 | 3 | 1.0 |
| Silicon (Si) | 3 | 3 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 2 | 2 | 1.0 |
| Metal oxygen | 2 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Acetyl | 1 | 1 | 1.0 |
| Carboxyl (COOH) | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Chitosan | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Bromine | 1 | 1 | 1.0 |
| Carbon bromine | 1 | 1 | 1.0 |
| Carbonate | 1 | 0 | 0.7 |
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 |
|---|---|---|---|
| starch | 1025, 1650, 1540 | Methacrylate, Acetate, C-O single bond | 2 |
| alginate | 1025, 1100, 1715 | Methacrylate, Acetate, Methoxy (OCH3) | 1 |
| copper oxide | 1025, 624, 1686 | Methacrylate, Acetate | 1 |
| dentin | 1025, 575, 1740 | 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 1025 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
“Citation: Chen,S.;Tan,H.;Zhang, Compared with sapphires from other origins, sapphires from this mine have three characteristic C.;Teng,Y.;Zu,E.Studyon cm-1, cm-1 infrared peaks of kaolinite at 930, 1025, and 1110 of which the single peak at”
Study on Gemological Characteristics of Blue Sapphires from Baw-Mar Mine, Mogok, Myanmar DOI: 10.3390/cryst11111275 -
Phosphate (PO4) confidence 1.0
“LLM confirmed rule peak-group candidate”
Root canal hydrophobization by dentinal silanization: Improvement of siliconbased endodontic treatment tightness DOI: 10.1002/jbm.b.32874 -
Acetate confidence 1.0
“cm-1 C-O-C The ratio of the integrated intensity of the polysaccharide The stretch occurs at 1025 in the spectrum of”
Gaffney 等 - 2015 - Characterization of Fine Mode Atmospheric Aerosols DOI: 10.1021/jp510361s -
Acetate confidence 1.0
“cm-1 firmed the alginate structure as all characteristic peaks were Figure 3 (a) shown the peak at 1025 for ALGA-1 cm-1, cm-1, cm-1, cm-1 C-O-C observed at 1025 which corresponds 1409 1595 2325 to the stretching vibration [44] cm-1 cm-1 (C-”
Enhancing proton conductivity of sodium alginate doped with glycolic acid in bio-based polymer electrolytes system DOI: 10.1007/s10965-020-02142-0 -
Carbohydrate confidence 1.0
“cm-1 995 of C were lower than that of CS, while the bandwidth at s 1025cm-1ofC sexhibitedanincreasingtrend[16].Thiscouldbeattributed to damage of crystalline structure in starch granules, which is also confirmed by XRD results.This in turn”
Gao 等 - 2021 - Synthetic mechanism of octenyl succinic anhydride DOI: 10.1016/j.ijbiomac.2021.01.082 -
Hydroxyl (O-H) confidence 1.0
“cm-1 corresponding to PO The peak at represented at 1025 cm-1 is represented due to the vibrational of the hydroxyl 630 cm-1 band in spectra group.”
Jaber 和 Kovacs - 2019 - Preparation and synthesis of hydroxyapatite bio-ce DOI: 10.14382/epitoanyag-jsbcm.2019.18 -
Carbon bromine confidence 1.0
“The intense bands situated at about 663 and 1025cm-1 of wavelength were assigned to the stretching vibrational movement of C-Br and”
Jing 等 - 2019 - Biosynthesis of copper oxide nanoparticles and the DOI: 10.1016/j.jphotobiol.2019.111557 -
C-O single bond confidence 1.0
“The bands near 1025cm(cid:2)1 starches at a DDA concentration of 48g/t are [SS: 65.6, 72.5], [CS: 1000 and are due to the presence of C-OH stretching”
Investigations on different starches as depressants for iron ore flotation DOI: 10.1016/j.mineng.2013.05.004
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