Alkyl C-H — FTIR absorption peaks and assignments
These are the characteristic FTIR wavenumbers where Alkyl C-H tends to absorb, compiled from published literature and ranked by supporting evidence. Each assignment is traceable to a source (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
Alkyl C-H is usually assigned by looking for a recurring cluster of characteristic peaks rather than one exact textbook number. The table below shows where the literature most often places this group in FTIR, ranked by accumulated evidence.
Characteristic FTIR peaks for Alkyl C-H
| Wavenumber (cm⁻¹) | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| 2920 | 211 | 185 | 1.0 |
| 2850 | 200 | 176 | 1.0 |
| 2900 | 167 | 149 | 1.0 |
| 2925 | 147 | 139 | 1.0 |
| 3000 | 136 | 126 | 1.0 |
| 2930 | 115 | 109 | 1.0 |
| 2924 | 114 | 112 | 1.0 |
| 2922 | 107 | 102 | 1.0 |
| 2926 | 91 | 84 | 1.0 |
| 2800 | 90 | 83 | 1.0 |
| 1450 | 85 | 81 | 1.0 |
| 2923 | 85 | 77 | 1.0 |
| 2854 | 84 | 77 | 1.0 |
| 2950 | 83 | 81 | 1.0 |
| 1460 | 83 | 79 | 1.0 |
| 2927 | 81 | 75 | 1.0 |
| 2852 | 65 | 62 | 1.0 |
| 2918 | 64 | 60 | 1.0 |
| 2853 | 63 | 59 | 1.0 |
| 2919 | 63 | 53 | 1.0 |
| 2960 | 63 | 52 | 1.0 |
| 2928 | 61 | 57 | 1.0 |
| 2921 | 59 | 52 | 1.0 |
| 1400 | 54 | 49 | 1.0 |
| 2916 | 51 | 47 | 1.0 |
| 2855 | 51 | 45 | 1.0 |
| 2929 | 50 | 48 | 1.0 |
| 1375 | 50 | 46 | 1.0 |
| 1465 | 50 | 43 | 1.0 |
| 1370 | 47 | 45 | 1.0 |
Showing the 30 best-supported peaks of 1917 total for Alkyl C-H.
Possible materials
Spectrum logic
A functional-group assignment becomes more confident when several expected bands appear together. Use this page to find the strongest-supported peaks, then confirm that the same sample exhibits a coherent pattern rather than a single isolated hit.
Real-world usage
These pages are useful for unknown material analysis, peak explanation in reports, polymer troubleshooting, and verifying whether a candidate material family is chemically plausible.
Common mistakes
- Using one functional-group page as a complete material verdict without checking the rest of the spectrum.
- Assuming the strongest band is always the most diagnostic one.
- Forgetting that processing, additives, aging, and mixtures can shift or broaden expected peaks.
Verification advice
Use DSC, GC-MS, or TGA when several material families share similar bands or when mixture effects make the FTIR assignment uncertain.
Literature behind these assignments
-
3075 cm⁻¹ confidence 1.0
“4ABN, the C-H stretching peaks are observed in IR at 3075 and 3030cm(cid:2)1”
Arjunan 等 - 2012 - Quantum chemical studies and vibrational analysis DOI: 10.1016/j.saa.2012.08.053 -
3097 cm⁻¹ confidence 1.0
“The deformation vibrations of NO group (rocking, 3097cm(cid:2)1 tigation, the C-H vibrations are observed at in the FT-IR 2 2 waggingandtoseveralnormalmodes)areinthelowfrequencyre3098cm(cid:2)1 spectrum and at in the FT-Raman spectrum, resp”
Arivazhagan 和 Rexalin - 2013 - Vibrational spectra, UV-vis spectral analysis and DOI: 10.1016/j.saa.2013.01.029 -
2850 cm⁻¹ confidence 1.0
“94(cid:5) 2955w 2954 C Hstretching C H 2850vw 1272+1583 2×1351 2709w 2×1195 2384vw”
Arjunan 等 - 2007 - Fourier transform infrared and Raman spectral assi DOI: 10.1016/j.saa.2006.09.044 -
2922 cm⁻¹ confidence 1.0
“Peaks at 2922 attributed to C-H and at 1105 is belong to C-O bond from ether or carboxylic acid groups.”
Arizka 等 - 2019 - Synthesis and Physical Properties Characterization DOI: 10.1088/1757-899X/546/4/042004 -
2927 cm⁻¹ confidence 1.0
“The luminescent properties cm-1 peak at 2927 corresponds to the C-H stretching vibraof ZrO are greatly affected by these intrinsic defects as they 2 cm-1 tions [39] and the observed peak at 2348 is related to introduces the donor or accepte”
Study of Copper Doped Zirconium Dioxide Nanoparticles Synthesized via Sol–Gel Technique for Photocatalytic Applications DOI: 10.1007/s10904-020-01616-4 -
1255 cm⁻¹ confidence 1.0
“OH group 1593 CH bending 1240 S=O stretching 1255”
Artemisia 等 - 2019 - The Properties of Brown Marine Algae Sargassum tur DOI: 10.14499/indonesianjpharm30iss1pp43 -
2017 cm⁻¹ confidence 1.0
“4 (2017) cm-1 υ 4-υ 2390-2350 δ(C-H) Stretching vibration Su and Sun (2017), Sujka et al.”
FT-IR spectroscopy with chemometrics for rapid detection of wheat flour adulteration with barley flour DOI: 10.1007/s00003-019-01267-9 -
840 cm⁻¹ confidence 1.0
“LLM confirmed rule peak-group candidate”
Arshad 等 - 2019 - Dielectric and Structural Properties of Poly(vinyl DOI: 10.1155/2019/5961563
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