What absorbs at 1995 cm⁻¹ in an FTIR spectrum?
A band near 1995 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 5 cited sources
Quick answer
A band near 1995 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.
Возможные назначения функциональных групп
| Функциональная группа | Подтверждающие факты | Цитируемые источники | Максимальная достоверность |
|---|---|---|---|
| Methoxy (OCH3) | 1 | 1 | 1,0 |
| Methacrylate | 1 | 1 | 1,0 |
| C-O single bond | 1 | 1 | 1,0 |
| Acetate | 1 | 1 | 1,0 |
| Carboxyl (COOH) | 1 | 1 | 1,0 |
| Water (H2O) | 1 | 1 | 1,0 |
| Amide | 1 | 1 | 1,0 |
| C c single bond | 1 | 0 | 1,0 |
Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.
Possible materials
| Материал | Поддерживающие пики | Overlapping groups | Цитируемые источники |
|---|---|---|---|
| Polyethylene | 1995, 1737, 1720 | Methacrylate, Acetate, 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 1995 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.
Литература, лежащая в основе этих назначений
-
Amide достоверность 1,0
“multiple functional groups,it is less useful for protein structure anti-symmetric stretch vibration is highly example, the CH 3 prediction than the amide I band (Jackson & Mantsch, 1995, intensive in the aleurone cell layer, indicating a hi”
Microprobing the molecular spatial distribution and structural architecture of feed-type sorghum seed tissue (Sorghum Bicolor L.) using the synchrotron radiation infrared microspectroscopy technique DOI: 10.1107/S0909049511023727 -
Water (H2O) достоверность 1,0
“cm-1 due to C=O stretching vibrations of the pectin and the The wavelengths ranged from 1700 to 1500 acids, but these absorption bands were usually overlapped by the water absorption band (Defernez & Wilson, 1995).”
Coelho 等 - 2020 - DOI: 10.1590/1981-6723.19418 -
Carboxyl (COOH) достоверность 1,0
“Giurginca et al., 2003) ν-C¼O 1732 aldehyde Stretching (Liu et al., 2011) 1705-1725 ν-C¼O ketone Stretching (Socrates) ν-C¼O 1714 carboxylic acid Stretching (Tidjani and Watanabe,1995;”
One year monitoring by FTIR of γ-irradiated multilayer film PE/EVOH/PE DOI: 10.1016/j.radphyschem.2016.03.010 -
Acetate достоверность 1,0
“ATR/FTIR indicated a distinct enhancement to the In: Plastics, fibres, rubbers, resins, starting and auxiliary matericm-1) cm-1) amide I (1650 and amide II (1550 bands als: degradation products, vol 2, 2nd ed., Hanser-VCH, Weinheim indicati”
Rahman 等 - 2018 - Characterization of new and fouled SWRO membranes DOI: 10.1007/s13201-018-0806-7 -
достоверность 0,8
“Text: 'intrinsic absorption at 1995'”
Lai 等 - 2020 - Spectroscopic features of natural and HPHT-treated DOI: 10.1016/j.diamond.2019.107642
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