What absorbs at 605 cm⁻¹ in an FTIR spectrum?
A band near 605 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 605 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 | 6 | 6 | 1.0 |
| Phosphate (PO4) | 3 | 2 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Methacrylate | 2 | 2 | 1.0 |
| C-O single bond | 2 | 2 | 1.0 |
| Acetate | 2 | 2 | 1.0 |
| Silicon (Si) | 2 | 2 | 1.0 |
| Silicon carbon | 2 | 2 | 1.0 |
| Phosphorus | 2 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Silicon-oxygen (Si-O) | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| Chlorine | 1 | 1 | 1.0 |
| Silicon silicon | 1 | 1 | 1.0 |
| Boron nitrogen | 1 | 1 | 1.0 |
| N-O bond | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
| C n single bond | 1 | 1 | 1.0 |
| Amide | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
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 605 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
-
confidence 1.0
“The peak at 605 cm-1 attributed to Cu(I)-O vibration of Cu 2O shits to 611 in the Cu 2O/ cellulose composite.”
Manuscript Preparation Instruction for Publishing in Computer Modeling in Engineering and Science (CMES) DOI: 10.3970/cmc.2018.03608 -
confidence 1.0
“Mn stretching and bands observed at 605, C O bending vibrations.”
Mahmood 等 - 2006 - Comparative vapour phase FTIR spectra and vibratio DOI: 10.1016/j.saa.2005.11.024 -
Amide confidence 1.0
“appearance of the SiC (cm 0.5 Cs 1206-cm(cid:3)1 peak Remark B C N O (605) coefficient 0.4 (cid:4) mc-Si7) Appeared p-type (cid:4) 0.3 Appeared n-type mc-Si (Fig.”
Second Harmonic Vibrational Mode of Substitutional Carbon in Cast-Grown Multicrystalline Silicon DOI: 10.1143/APEX.4.051401 -
Silicon silicon confidence 1.0
“A measurement of the vibrational C local Methfessel22 predicted a negative shift in the Si-Si peak for (cid:3)605 cm-1 can be used to quantify the amount of mode at al.13 et SiGeC alloys using theoretical calculations.”
Wasyluk 等 - 2010 - Raman and Fourier transform infrared study of subs DOI: 10.1063/1.3284937(cid:5) -
Metal oxygen confidence 1.0
“By analyzing particles formed by the self-decomposed ferrate and ferrate reacted with BPF with Fourier transform infrared spectroscopy (FTIR), it was found that the Fe-O peak red630cm-1 605cm-1, eOH to and stretch peak became broad and inte”
Ferrate oxidation of bisphenol F and removal of oxidation products with ferrate resulted particles DOI: 10.1016/j.cej.2019.123167 -
confidence 1.0
“cm-1 C-N The vibrations at 1462 and 1290 are generated because of stretching C-Cl and bending vibrations, while the bond is responsible for the bands at 605 and cm-1 cm-1 (M-O) 633 [27].”
New Hybrid PVC/PVP Polymer Blend Modified with Er2O3 Nanoparticles for Optoelectronic Applications DOI: 10.3390/polym15030684 -
Phosphate (PO4) confidence 1.0
“Phosphate bands could be identified at 605, 575 and 563 The FTIR bands obtained confirm that 3243-.”
Ion-Substituted Carbonated Hydroxyapatite Coatings for Model Stone Samples-8pt DOI: 10.3390/coatings9040231 -
confidence 1.0
“In 2852 cm(cid:1)1 is observed which corresponds to metal nitrogen stretching CZTS sample a strong band at 605 (x¼0-1) Fig.”
CZTSxSe1−x nanocrystals_ Composition dependent method of preparation, morphological characterization and cyclic voltammetry data analysis DOI: 10.1016/j.solmat.2016.06.030
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