What absorbs at 937 cm⁻¹ in an FTIR spectrum?
A band near 937 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 937 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 |
|---|---|---|---|
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| Carbohydrate | 3 | 2 | 1.0 |
| Alkyl C-H | 3 | 2 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 1 | 1.0 |
| Methacrylate | 2 | 1 | 1.0 |
| Acetate | 2 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Silanol (Si-OH) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Methyl | 1 | 0 | 1.0 |
| Protein random coil | 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 |
|---|---|---|---|
| cellulose | 937, 1735, 1650 | Alkyl C-H, Hydroxyl (O-H), Carbohydrate | 1 |
| TiO2 | 937, 1700, 1093 | Hydroxyl (O-H), Alkyl C-H | 1 |
| TiO | 937, 1730, 1699 | Alkyl C-H, Hydroxyl (O-H) | 1 |
| silica nanoparticles | 937, 1718, 2925 | Silicon (Si), Alkyl C-H, Hydroxyl (O-H) | 1 |
| chitin | 937, 1650, 1655 | Alkyl C-H | 1 |
| protein | 937, 1650, 1640 | 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 937 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
-
Carbohydrate confidence 1.0
“PC 1 2 cm-1 ates spectra based on the free glucose in solution from the also shows that there is loss of a peak at 937 in the N-C-C glucose spiked in sample.”
Mcavan 等 - 2020 - Quantification of protein glycation using vibratio DOI: 10.1039/c9an02318f -
Phosphate (PO4) confidence 1.0
“cm-1 to monoprotic pPentaM shifts the P=O from 1265 to 1224 The bands at 1124-1163 1163 cm-1 in DPA are assigned to P=O and those at 999 and 937 cm-1 to the P-O(H).”
The Effect of Hydrogen Bonding in Enhancing the Ionic Affinities of Immobilized Monoprotic Phosphate Ligands DOI: 10.3390/ma10080968 -
Silicon-oxygen (Si-O) confidence 1.0
“Furthermore, the cm-1 characteristic vibration at 937 can be assigned to O-Si-O bond [38].”
Magnetron sputtering technique for analyzing the influence of RF sputtering power on microstructural surface morphology of aluminum thin films deposited on SiO2/Si substrates DOI: 10.1007/s00339-021-04892-0 -
Alkyl C-H confidence 1.0
“On the other hand, similar bands were observed at 937 885 cm-1, cm-1 743 and 1455 in iRoot, representing C-H stretching.”
Assiry 等 - 2023 - Microstructural and Elemental Characterization of DOI: 10.3390/app13074517 -
Silicon (Si) confidence 1.0
“The next peak at 937 corresponds corresponds to Si-OH and the last absorption peak around 3300 cm-1 is due to free O-H stretching cm-1 to Si-OH and the last absorption peak around 3300 is due to free O-H stretching bands [23].”
Novel Synthesis of Core-Shell Silica Nanoparticles for the Capture of Low Molecular Weight Proteins and Peptides DOI: 10.3390/molecules22101712 -
Alkyl C-H confidence 1.0
“The peak at 859 cm-1 was assigned to the C-H stretching of the disturbed rings of cellulose/chitin, while the peaks at 937 and 1115 cm-1 were assigned to the deformation of the -C-Hbending and”
Physicochemical and Photocatalytic Properties of 3D-Printed TiO2/Chitin/Cellulose Composite with Ordered Porous Structures DOI: 10.3390/polym14245435 -
Ring structure confidence 1.0
“Another important cm-1 absorption band was observed at 937.04 in the spectra of the developed hydrogel was due to the vibration of α-(1 ! 4) glucopyranose ring of β-CD, thus supporting that β-CD was grafted onto polymeric network.”
Cross-linked #_#x03B2;-cyclodextrin and carboxymethyl cellulose hydrogels for controlled drug delivery of acyclovir DOI: 10.1371/journal.pone.0172727 -
Acetate confidence 1.0
“965 967 965 (+) -C-O-Pstretching in RNA 937 937 (+)”
tRNA as a stabilizing matrix for fluorescent silver clusters: photophysical properties and IR study DOI: 10.1039/c9na00112c
Have a spectrum with this band?
Upload your FTIR spectrum and get a full interpretation report — peak assignments with literature citations, library matches, and a literature-backed analysis — in seconds.