What absorbs at 627 cm⁻¹ in an FTIR spectrum?
A band near 627 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 627 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 |
|---|---|---|---|
| Metal oxygen | 3 | 3 | 1.0 |
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Phosphate (PO4) | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| Carbohydrate | 1 | 1 | 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 |
|---|---|---|---|
| PVA | 627, 1660, 2930 | Hydroxyl (O-H) | 1 |
| starch | 627, 1650, 1540 | Hydroxyl (O-H) | 1 |
| glycerol | 627, 1585, 1630 | Hydroxyl (O-H) | 1 |
| nanoparticles | 627, 1732, 1647 | Hydroxyl (O-H), Metal oxygen | 1 |
| zirconia | 627, 1100, 460 | Phosphate (PO4), Hydroxyl (O-H), Metal oxygen | 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 627 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”
Novel tri-phase heterostructured ZnO–Yb2O3–Pr2O3 nanocomposite; structural, optical, photocatalytic and antibacterial studies DOI: 10.1016/j.ceramint.2020.01.130 -
Metal oxygen confidence 1.0
“The M-O stretching is shown at 627 Appearance of dissolutionofPVAinwater,5 wt%nano-sizedNi(OH) 2was these peaks confirmed the chemical structure of pristine addedinaslowmannerundervigorousstirringwithnitrogen”
Parveen 等 - 2009 - Synthesis and characterizations of nano-sized Ni(O DOI: 10.1007/s10853-009-3826-8 -
Hydroxyl (O-H) confidence 1.0
“A strong peak at 627 cm-1 is attributed to the bending mode of the (OH)- group [9], and similar to”
Structural Characterization of Low-Sr-Doped Hydroxyapatite Obtained by Solid-State Synthesis DOI: 10.3390/cryst13010117 -
Carbohydrate confidence 1.0
“The first band located at 627 cm-1 is associated with vibrations of the glucose rings' skeletal model;”
Physical-Mechanical Behavior and Water-Barrier Properties of Biopolymers-Clay Nanocomposites DOI: 10.3390/molecules26216734 -
confidence 1.0
“676.10 and C-Cl stretch vibration of alkyl halides cm-1 626.8 cm-1 7.”
Chauhan 等 - 2018 - Biofabrication of Copper Nanoparticles A Next-gen DOI: 10.4274/tjps.52724 -
confidence 1.0
“Comparison of the IR spectra of all 627cm-1 of the three kinds of nanoparticles, absorption peaks at are observed, corresponding to the Fe-O vibration from the original cm-1, cm-1, The absorption bands at 794 953 1075 magnetite phase[25].”
A new method of synthesis well-dispersion and dense Fe3O4@SiO2 magnetic nanoparticles for DNA extraction DOI: 10.1016/j.jmmm.2017.03.025 -
confidence 1.0
“The second peak appeared at 627 C appeared at 627 °C and was attributed to the decomposition of oxygen-containing heterocyclic ring and was attributed to the decomposition of oxygen-containing heterocyclic ring and the carboxyl ◦ and the ca”
Thermal Transformation of Carbon and Oxygen-Containing Organic Compounds in Sewage Sludge During Pyrolysis Treatment DOI: 10.3390/en12122258 -
Phosphate (PO4) confidence 1.0
“erate asymmetric P-O bending was measured at 612, and 627 cm-1 In addition, peaks emerged for the t-ZrO2 peaks at 145, 222, 263, 381, 473, and 637 cm-1, and m-ZrO2 peaks were observed at 178 and 189 cm-1, corresponding to the Zr-O vibra- °C”
Ponnusamy 等 - 2022 - Synthesis, Structural, and Mechanical Behavior of DOI: 10.3390/ma15082924
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