What absorbs at 506 cm⁻¹ in an FTIR spectrum?
A band near 506 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 5 cited sources
Quick answer
A band near 506 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) | 2 | 2 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Boron nitrogen | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| graphene | 506, 1720, 2097 | Hydroxyl (O-H) | 1 |
| TiO2 | 506, 1700, 1093 | Hydroxyl (O-H), Alkyl C-H | 1 |
| ZnO | 506, 1400, 3430 | Hydroxyl (O-H), Alkyl C-H | 1 |
| rGO | 506, 2358, 2930 | Hydroxyl (O-H), Alkyl C-H | 1 |
| PANI | 506, 2930, 1300 | Alkyl C-H, Ring structure | 1 |
| zirconia | 506, 1100, 460 | 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 506 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
-
Metal oxygen confidence 1.0
“LLM confirmed rule peak-group candidate”
Nurdiansah 等 - 2020 - Synthesis of ZnOrGOTiO2 Composite and Its Photoc DOI: 10.1088/1757-899X/833/1/012028 -
C c single bond confidence 1.0
“1930 CH (bending)/C=O 2 C-O-H (bending)/C-O 1362 (stretching), alcohol, ester, ether, carboxylic acid 1078 C-C-O (asymmetric stretching) bending)/C-H 506 O-H (Out-of-plane (bending)”
Hayyan 等 - 2015 - Functionalization of graphene using deep eutectic DOI: 10.1186/s11671-015-1004-2 -
Phosphate (PO4) confidence 1.0
“506 752 978 1642 2382 and 3464 The band at around 506 is 43cm-1 506 cm-1 is attributed to the bending vibrations (PO43-) of O-P-O [15,16,22] The absorption bands at attributed to the bending vibrations (PO ) of O-P-O [15,16,22] The absorpti”
Influence of ZrO2 Addition on Structural and Biological Activity of Phosphate Glasses for Bone Regeneration DOI: 10.3390/ma13184058 -
Amide confidence 1.0
“1146cm(cid:2)1 early T-O-T Bands at 1298 and are due to vibrations of the C-N system (N-B-N) and the C¼N system (N¼ amine.32 Q¼N) of the acrylic secondary The bands at 506 and 695cm(cid:2)1 bending.33 are characteristic of C-H out-of-plane”
Safidine 等 - 2013 - Thermoelectrical characterization of new material DOI: 10.1038/pj.2012.232; -
Hydroxyl (O-H) confidence 1.0
“Among them, the peak at about1000cm-1iscausedbyδ(O-H)in-planebending is related to the vibration, and the peak at 506 cm-1 γ(O-H) out-of-plane bending vibration.”
Xu 和 Yu - 2019 - PRESSED GIBBSITE AND CALCITE AS A RHODOCHROSITE IM DOI: 10.5741/GEMS.55.3.406
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