What absorbs at 3047 cm⁻¹ in an FTIR spectrum?
A band near 3047 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 4 cited sources
Quick answer
A band near 3047 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 | 3 | 3 | 1.0 |
| Aromatic ring | 2 | 2 | 1.0 |
| Amide | 1 | 1 | 1.0 |
| Amino acid | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Alkene (C=C) | 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 |
|---|---|---|---|
| biomass | 3047, 1082, 1282 | Alkyl C-H, Aromatic ring, Amide | 1 |
| coal | 3047, 1600, 3030 | Alkyl C-H, Aromatic ring | 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 3047 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
“The spectrum for 1-MN, shown in Figure 2b, exhibited the aromatic cm-1, cm-1, C-H stretching band at 3047 the aliphatic C-H stretching band at 2980-2870 as well as cm-1.”
Ketren 等 - 2019 - Investigation on Conversion Pathways in Degradativ DOI: 10.3390/en12030528 -
Alkyl C-H confidence 1.0
“FTIR spectra of control perylene (Fig.7a) showed the -1 charactereristic absorption peaks at 3047 cm (=CH stretch in -1 aromatic rings), 2850.79-2953.02 cm (C-H stretching in cyclic -1 Fig.”
Mandal 和 Das - 2018 - Biodegradation of perylene and benzo [ghi] perylen DOI: 10.22438/jeb/39/1/MRN-540 -
Alkene (C=C) confidence 1.0
“1,6-Bis[4-(naphthyliminomethylidene)-phenoxy]-hexane cm-1): ν, FTIR (KBr, 3047 (=C-H stretch of the aromatic rings), 2941-2856 (C-H stretch of aliphatic chains), 1618 (-N=CHstretch), 1605, 1565, 1513 (C-C ring stretch), 1246, 1H-NMR 1166 (C”
Mesomorphic Behavior of Symmetric Azomethine Dimers Containing Different Chromophore Groups DOI: 10.3390/molecules26082183 -
confidence 1.0
“The typically broad band centered at 3159 such as acetic, citric and butyric acids) (Shumilina et al., 2020), the mainly correN\\H C_O cm-1 signal at 1666 sponds to the stretch in peptides and amino acids (the shoulder can correspond to the”
Comprehensive characterization of industrial wastewaters using EEM fluorescence, FT-IR and 1H NMR techniques DOI: 10.1016/j.scitotenv.2021.150417
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 confidence-rated evidence chain — in seconds.