What absorbs at 1992 cm⁻¹ in an FTIR spectrum?
A band near 1992 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 1992 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 |
|---|---|---|---|
| Aromatic ring | 3 | 3 | 1.0 |
| Amide | 3 | 2 | 1.0 |
| N h | 2 | 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 |
| Secondary amine | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Alkyl C-H | 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 |
|---|---|---|---|
| gelatin | 1992, 1652, 3300 | Amide, N h | 2 |
| silver nanoparticles | 1992, 1636, 1631 | Amide, N h, Methoxy (OCH3) | 2 |
| Polyethylene | 1992, 1737, 1720 | Methoxy (OCH3), Aromatic ring | 1 |
| Pt | 1992, 1042, 1230 | Methoxy (OCH3) | 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 1992 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
“Indian J Exp Biol C-H droxy group,H-bonded OH stretch, methylene stretch in James AA (1992) Mosquito molecular genetics: the hands that feed bite 257:37-38 back.”
Marimuthu 等 - 2013 - Eco-friendly microbial route to synthesize cobalt DOI: 10.1007/s00436-013-3601-2 -
confidence 1.0
“The Amide II band is due to combination of a C-N N 325 stretch and N-H deformation in the gelatin structure (Bandekar, 1992).”
Rheological, micro-structural and sensorial properties of camel milk yogurt as influenced by gelatin DOI: 10.1016/j.lwt.2018.09.008 -
Acetate confidence 1.0
“The peaks at 1757 and 1200 are attributed to the 22,p.97,J.O'M.Bockris,B.E.Conway,B.E.White,Editors,PlenumPress,New mode25 carbonyl stretching and C-O-C stretching modes of ~1992!.”
Sanicharane 等 - 2002 - In situ 50 degrees C FTIR spectroscopy of Pt and P DOI: 10.1149/1.1464883 -
Alkene (C=C) confidence 1.0
“thiocyanate, or isothiocyanate (-NCS) (monosubstituted) GSE-AgNPs 1634 Medium Alkenyl C=C stretch Olefinic alkene 1992/1966 Weak Aromatic combination bands Aromatic ring Transition metal carbonyls, The GC/MS analysis of GSE showed the prese”
The Antimicrobial Activities of Silver Nanoparticles from Aqueous Extract of Grape Seeds against Pathogenic Bacteria and Fungi DOI: 10.3390/molecules26196081 -
Amide confidence 1.0
“Saudi Pharm J 25:861-867 Bandekar J (1992) Amide modes and protein conformation.”
Theranostic RGD@Fe3O4-Au/Gd NPs for the targeted radiotherapy and MR imaging of breast cancer DOI: 10.1186/s12645-023-00214-6 -
Aromatic ring confidence 1.0
“The bands at 1421 and cm-1 1418 in PP and PS were assigned to the C-H deformation in methoxyl and aromatic skeletal vibrations in lignin (Faix 1992;”
Elmas 和 Yilgor - 2020 - Chemical and Thermal Characterizations of Pinus sy DOI: 10.1515/hf- -
Acetate confidence 1.0
“C-O C¼O and as the stretching gives a signal less intense than the stretching, this Carlsson,1992;”
One year monitoring by FTIR of γ-irradiated multilayer film PE/EVOH/PE DOI: 10.1016/j.radphyschem.2016.03.010 -
Amide confidence 1.0
“The C-N stretching vibrations coupled with N-H inplane bending vibrations, weak contributions from C-C bond stretching vibrations and C=O in-plane bending give rise to Amide III absorption (Bandekar 1992).”
Irfanita 等 - 2022 - Attenuated Total Reflectance-Fourier Transform Inf DOI: 10.21315/tlsr2022.33.2.7
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