What absorbs at 930 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 930 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

Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.

Possible materials

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 930 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

• Carbonate confidence 1.0

  “S1 S1-12h S1-24h S1-48h S1-72h S1-1 week Remarks 461.1 461.1 461.1 450.9 471.3 420.4, 416.1 Peak intensity changes as hydration time increases 522.2 522.2 527.3 527.3 522.2 532.4 Peak intensity changes as hydration time increases SO42(cid: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
• Aromatic ring confidence 1.0

  “The intensity gradually and the absorption intensity of the peak at cm(cid:2)1 of the peak at 930 attributed to tri-substituted benzene cm(cid:2)1 decreases along with the increase of temperature 930 ring that is attached with oxazine ring”

  Cao 等 - 2008 - Synthesis and thermal properties of the thermosett DOI: 10.1016/j.polymdegradstab.2007.10.002
• confidence 1.0

  “As the additive fluorine concentration increases, the intensity of Si-F peak cm-1 increases and the frequency of the Si-O stretching stretching vibrations located at 930 cm-1 vibration mode centered at 1060 shifts towards higher wavenumber.”

  Chabane 等 - 2009 - Characterization of SiOF thin films deposited by P DOI: 10.4028/www.scientific.net/MSF.609.59
• Hydroxyl (O-H) confidence 1.0

  “Citation: Chen,S.;Tan,H.;Zhang, Compared with sapphires from other origins, sapphires from this mine have three characteristic C.;Teng,Y.;Zu,E.Studyon cm-1, cm-1 infrared peaks of kaolinite at 930, 1025, and 1110 of which the single peak at”

  Study on Gemological Characteristics of Blue Sapphires from Baw-Mar Mine, Mogok, Myanmar DOI: 10.3390/cryst11111275
• C c single bond confidence 1.0

  “cm-1 in C-OH group and stretching of C-C in the carbohydrate The area below 930 (from 930 cm-1) to about 700 is the vibration area, which is very characteristic for vibrations from the anomeric region”

  Identification of sugars and phenolic compounds in honey powders with the use of GC–MS, FTIR spectroscopy, and X-ray diffraction DOI: 10.1038/s41598-020-73306-7
• Silicon (Si) confidence 1.0

  “Figure 3 also tends to strengthen the Si-O bonds and change Si-O-Si shows the Si-F stretching mode peak located at around 930 bonding angles.”

  Lee 和 Park - 1996 - Effect of fluorine on dielectric properties of SiO DOI: 10.1063/1.363512
• Borate confidence 1.0

  “(iii) Two successive distinct broad bands with the first extended It is to be mentioned that the clear identification and strong -1 from 780 to 1150 cm and showing two peaks at 930 and appearance of the vibrational bands due to both borate”

  Marzouk 等 - 2021 - Judd-Ofelt analysis of spectroscopic measurements DOI: 10.1016/j.molstruc.2021.130925
• Metal oxygen confidence 1.0

  “Ti-O-Si portant feature to be noted here is the presence of the cm-1 ∼930 absorption peak located at [18,20], which is a clear Ti-O-Si indication that the Si, Ti and O atoms were mixed at the atomic (b) clearly shows that the relative inten”

  Sarkar 等 - 2007 - Dielectric properties of sol-gel derived high-k ti DOI: 10.1016/j.tsf.2006.11.155