Aldehyde (CHO) — FTIR absorption peaks and assignments

Quick answer

Aldehyde (CHO) is usually assigned by looking for a recurring cluster of characteristic peaks rather than one exact textbook number. The table below shows where the literature most often places this group in FTIR, ranked by accumulated evidence.

Characteristic FTIR peaks for Aldehyde (CHO)

Showing the 30 best-supported peaks of 121 total for Aldehyde (CHO).

Spectrum logic

A functional-group assignment becomes more confident when several expected bands appear together. Use this page to find the strongest-supported peaks, then confirm that the same sample exhibits a coherent pattern rather than a single isolated hit.

Real-world usage

These pages are useful for unknown material analysis, peak explanation in reports, polymer troubleshooting, and verifying whether a candidate material family is chemically plausible.

Common mistakes

• Using one functional-group page as a complete material verdict without checking the rest of the spectrum.
• Assuming the strongest band is always the most diagnostic one.
• Forgetting that processing, additives, aging, and mixtures can shift or broaden expected peaks.

Verification advice

Use DSC, GC-MS, or TGA when several material families share similar bands or when mixture effects make the FTIR assignment uncertain.

Literature behind these assignments

• 1745 cm⁻¹ confidence 1.0

  “cm(cid:3)1 1747cm(cid:3)1 1745cm(cid:3)1 peak at 1745 on both spectra exhibited similar intensity for which showed stronger than that at of C4 cm(cid:3)1 the content of aldehydes, ketones and carbonyl stretching vibrain intensity.”

  Chen 等 - 2014 - Determination of chemical changes in Isatis indigo DOI: 10.1016/j.saa.2014.01.048
• 1730 cm⁻¹ confidence 1.0

  “appearance of carboxylic acid and aldehyde peaks at 1730 and 3.1.”

  Chu 和 Yaylayan - 2009 - FTIR monitoring of oxazolidin-5-one formation and DOI: 10.1016/j.carres.2008.10.011
• 1020 cm⁻¹ confidence 1.0

  “On the other hand, peak 3 cm-1 at 1020 of the TCHO region represents non-structural CHO such as starch [15].”

  Gene-Transformation-Induced Changes in Chemical Functional Group Features and Molecular Structure Conformation in Alfalfa Plants Co-Expressing Lc-bHLH and C1-MYB Transcriptive Flavanoid Regulatory Genes: Effects of Single-Gene and Two-Gene Insertion DOI: 10.3390/ijms18030664
• 900 cm⁻¹ confidence 1.0

  “EXE 9 and CRE + EXE 9), = = = cating bands assigned to the NH stretching vibrations feeding and supplementation protocols, tissue prepacm21) (~3000-3500 and (b) indicating bands assigned ration, and FT-IR spectrometry evaluation were also t”

  Jeronimo 等 - 2012 - Detection of Creatine in Rat Muscle by FTIR Spectr DOI: 10.1007/s10439-012-0549-9
• 1453 cm⁻¹ confidence 1.0

  “The 2928cm-1 peaks positioned at about 1453 and of wavelength were due to the stretching C-H of alkane methyl and aldehyde doublet groups.”

  Jing 等 - 2019 - Biosynthesis of copper oxide nanoparticles and the DOI: 10.1016/j.jphotobiol.2019.111557
• 1735 cm⁻¹ confidence 1.0

  “Attention should be paid to a cm-1) very important area, which is only slightly marked in our spectra (with a maximum at about 1735 and is due to the stretching vibrations of functional groups such as ketone C = O of fructose and aldehyde C”

  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
• 1750 cm⁻¹ confidence 1.0

  “The bands at 1800-1600 with a cm-1, prominent peak at 1750 were assigned to C=O stretching vibrations of aldehydes and D ketones [29].”

  Nkwain 等 - 2018 - Coupling pyrolysis with mid-infrared spectroscopy DOI: 10.1016/j.jaap.2018.04.004
• 1727 cm⁻¹ confidence 1.0

  “In addition, Cya produced a peak at 1727 due to stretching vibration of the cm-1, aldehyde group.”

  Improvement of stability due to a cyclamen aldehyde/β-cyclodextrin inclusion complex DOI: 10.1016/j.molstruc.2020.128161