What absorbs at 674 cm⁻¹ in an FTIR spectrum?
A band near 674 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 6 cited sources
Quick answer
A band near 674 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 |
|---|---|---|---|
| Metal oxygen | 2 | 2 | 1.0 |
| S eq o | 1 | 1 | 1.0 |
| S s | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| C-S single bond | 1 | 1 | 1.0 |
| N n bond | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| hematite | 674, 1030, 469 | Metal oxygen | 1 |
| ZnO | 674, 1400, 3430 | Metal oxygen, Alkyl C-H | 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 674 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
-
N n bond confidence 1.0
“cm-1, extra absorption bands at 674 and 1589 at the same 0exp(-σ D) = N N time the other absorption bands completely destructed with σ where is the cross section.”
Nagabhushana 等 - 2009 - Swift heavy ion irradiation induced phase transfor DOI: 10.1016/j.ssc.2009.07.049 -
Metal oxygen confidence 1.0
“LLM confirmed rule peak-group candidate”
Wang 和 Jiang - 2011 - Synthesis and Characterization of LiNbO3 Powders b DOI: 10.1080/00150193.2011.554260 -
C-S single bond confidence 1.0
“O-H To investigate the stability and with stretching and confirms the presence of Lcysteine.37 cm-1 C-S reusability of NZC-g-PANI, the simultaneous BG and MO dye The short band at 674 represents the adsorption-desorption tests were executed”
Bir 等 - 2022 - Multifunctional Ternary NLPZnO@L-cysteine-grafted DOI: 10.1021/acsomega.2c04936 -
Alkyl C-H confidence 1.0
“The peak at 1041 is of a primary alcoholic group of cm-1 CH 2OH and another peak at 674 may be due to CH rocking vibrations, (Deo et al., 2001).”
Farghaly 等 - 2021 - Physicochemical study and application for pyrolusi DOI: 10.37190/ppmp/131944 -
confidence 1.0
“cm-1 cm-1 As can be seen, the peak at 518 and wide peak at 674 are related to Fe-O, Al-O, and Fe-Al-O show-”
Heteropolyacid coupled with cyanoguanidine decorated magnetic chitosan as an efficient catalyst for the synthesis of pyranochromene derivatives DOI: 10.1038/s41598-022-21196-2 -
S s confidence 1.0
“C-S stretching P7 1019.856 1064.135 1032.714 s S=O stretching P 674.190 718.470 694.189 s 6 SO2 symmetric”
Rapid Estimation of Sulfur Content in High-Ash Indian Coal Using Mid-Infrared FTIR Data DOI: 10.3390/min13050634
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 literature-backed analysis — in seconds.