What absorbs at 973 cm⁻¹ in an FTIR spectrum?
A band near 973 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 973 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 |
|---|---|---|---|
| Alkyl C-H | 6 | 6 | 1.0 |
| Silicon-oxygen (Si-O) | 3 | 2 | 1.0 |
| Phosphate (PO4) | 2 | 2 | 1.0 |
| C-O single bond | 2 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Silicon (Si) | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 0 | 1.0 |
| Methacrylate | 1 | 0 | 1.0 |
| Acetate | 1 | 0 | 1.0 |
| N-O bond | 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 | 973, 2924, 1743 | Alkyl C-H, C-O single bond | 1 |
| polypropylene | 973, 1030, 1600 | Alkyl C-H, C-O single bond | 1 |
| Chitosan | 973, 1650, 1655 | Alkyl C-H, C-O single bond | 1 |
| PVC | 973, 834, 1195 | Alkyl C-H, C-O single bond | 1 |
| PVDF | 973, 1160, 840 | 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 973 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
-
Alkyl C-H confidence 1.0
“C-CH involves the CH rocking, the stretching, the CH bending and the CH twisting -band at 998 3 3 2 cm1 modes in the crystalline phase, while the -band at 973 belongs to the CH rocking and the axial and 3”
Chen 等 - 2015 - The spatial correlation between crystalline and am DOI: 10.1007/s10118-015-1613-3 -
confidence 1.0
“-1 cm-1 peak centred at 973 cm The shift of the Si-O stretching vibrations from 973 in PGV and PGN nanoclay was cm-1 attributed to the distinctive nanoplates of the tetra-hydrate in nanoclays to 1,019 in nanoclay-PAA solutions cm-1 layers o”
Fareed 和 Stamboulis - 2014 - Nanoclays reinforced glass ionomer cements disper DOI: 10.1007/s10856-013-5058-3 -
confidence 1.0
“Apparently, the contained <2.0 wt% nanoclays, exhibited generally cm-1 slightly higher CS, similar DTS and FS compared Si-O stretching peak which was present at 973 to the control cement groups.”
Fareed 和 Stamboulis - 2014 - Nanoclay addition to a conventional glass ionomer DOI: 10.4103/1305-7456.143619 -
Alkyl C-H confidence 1.0
“The out of plane C-H bending is shown by the band at 973 [23].”
Ramadan 和 Ismail - 2022 - Tunning the Physical Properties of PVDFPVCZinc F DOI: 10.21203/rs.3.rs-935328/v1 -
C c single bond confidence 1.0
“LLM confirmed rule peak-group candidate”
Ramli 等 - 2019 - Synthesis, characterization, and morphology study DOI: 10.1007/s10965-019-1952-9 -
Alkene (C=C) confidence 1.0
“The wavenumbers at 973 and 976 cm-1 can be assigned to secondary oxidation These results suggest that CBLO produced more trans double bonds and secondary oxiproducts, such as aldehydes or ketones, supporting isolated trans-double bonds [49]”
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
“Because of the analogy between nanoclay composites revealed that the addition of nanoRaman and Fourier transform infrared (FTIR) methclays affected the absorption bands located at 973 and cm-1, ods, it was expected that FTIR spectroscopy co”
Fourier transform infrared spectroscopy and wide-angle X-ray scattering: Investigations on polypropylene–vapor-grown carbon nanofiber composites DOI: 10.1002/app.35576 -
Alkyl C-H confidence 1.0
“The peaks at 973, 998, and 1168 were attributed to 3 -CH rocking vibration.”
Thin Film Mixed Matrix Hollow Fiber Membrane Fabricated by Incorporation of Amine Functionalized Metal-Organic Framework for CO2/N2 Separation DOI: 10.3390/ma14123366
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