What absorbs at 884 cm⁻¹ in an FTIR spectrum?
A band near 884 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 884 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 |
|---|---|---|---|
| Silicon-oxygen (Si-O) | 3 | 3 | 1.0 |
| Metal oxygen | 2 | 2 | 1.0 |
| Carbonate | 2 | 2 | 1.0 |
| Siloxane (Si-O-Si) | 1 | 1 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Ring structure | 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 |
|---|---|---|---|
| alumina | 884, 460, 1000 | Metal oxygen, Siloxane (Si-O-Si), Silicon-oxygen (Si-O) | 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 884 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
“659.7 CO32(cid:2) u2 Out-of-plane bending vibration of 883.7 Strong u3 929.6 Very strong Si-O asymmetric stretching vibration of silicate SO42 u3 S-O stretching vibration of 1097 Small shoulder 1114.2”
Theoretical and experimental study of structures and properties of cement paste The nanostructural aspects of C–S–H DOI: 10.1016/j.jpcs.2011.05.001 -
Ring structure confidence 1.0
“Fourier transform infra-red (FTIR) analysis cm-1 confirm 3:Ce3+ cm-1 The FTIR spectra of CaSiO phosphor was recorded in the range 400 - 4000 to the functional groups presentintheobtainedsamples,Fig.2.FTIRspectrashowstrongtransmittancepeaksa”
Dhanu 等 - 2020 - Photoluminescence of mixed phase CaSiO3Ce3+ nanop DOI: 10.1016/j.ijleo.2020.165139 -
Aromatic ring confidence 1.0
“9 is attributed to 1,4-disubstitution of the aromatic ring inpolyaniline.However,therearethreepeaksat884(w),854 (w)cm-1 (m), and 800 on curve 1 in Fig.”
Li 和 Mu - 2005 - The electrochemical activity of sulfonic acid ring DOI: 10.1016/j.synthmet.2004.12.015 -
Carbonate confidence 1.0
“Furthermore, a closer look atthe singlet band 2-1 at 861-864 is probably due to the n ACC.15,32,33 absorption band of carbonate groups from 2-3 singlet reveals a progressive peak shift from 884 (keel), n cm(cid:2)1 887 (needles), to 888 (pl”
Long 等 - 2012 - From synthetic to biogenic Mg-containing calcites DOI: 10.1039/c2cp22453d -
confidence 1.0
“The traces of the organic cm-1 materials from the PVP were at 1535 and 2787 and cm-1, are associated with Si-O stretching at 884, and 889 could be attributed to C-H bending vibrations [47, 48].”
Alibe 等 - 2019 - Effects of polyvinylpyrrolidone on structural and DOI: 10.1007/s10973-018-7874-7 -
Protein confidence 1.0
“cm-1 Increase in absorption at ~884 due to alterations in phosphorylated proteins suggest that more extensive phosphorylation occurs in malignant compared to benign samples.”
ATR-FTIR spectroscopy as adjunct method to the microscopic examination of hematoxylin and eosin-stained tissues in diagnosing lung cancer DOI: 10.1371/journal.pone.0233626 -
confidence 1.0
“ESI-MS molecular-ion peak 884.42, corresponding to H+ + 1H [Zn(L5) ].”
Gusev 等 - 2020 - Synthesis, Photoluminescence and Electrical Study DOI: 10.3390/ma13245698 -
confidence 1.0
“The band at cm-1 δ corresponds to the sAl-O-H mode of boehmite 1,072 cm-1 and the bands at 884, 740, 621, and 479 are attributed Al-O to the bonds of boehmite (Li et al.”
Liu 等 - 2012 - Dechlorinating transformation of propachlor throug DOI: 10.1007/s11368-012-0506-0)
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