What absorbs at 1204 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1204 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.

Posibles asignaciones de grupos funcionales

La clasificación refleja la evidencia acumulada de la literatura, no una única regla autorizada. Siempre confirme según el contexto de su muestra.

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 1204 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.

Literatura detrás de estas asignaciones

• Acetate confianza 1,0

  “C-O stretching vibration C-F 1204, 1148 1203, 1149 C-F stretching PFOA-modified”

  Ganie 等 - 2020 - Synthesis and Characterization of a New Surface-Mo DOI: 10.1155/2020/8814260
• C-O single bond confianza 1,0

  “The peaks at 1204 and 1036 Figure 3) was considered to arise from many 0% RH belonged to C-OH in plane bending types of adsorbed water.”

  Characterizing molecular structure of water adsorbed by cellulose nanofiber film using in situ micro-ftir spectroscopy DOI: 10.1080/02773813.2017.1306078
• Alkyl C-H confianza 1,0

  “O iment showed that during this degradation step, the bromine A articles groups of the polymer end functionalities are eliminated, and cm-1 the peaks at 1204 and 1164 correspond to the CH wagare governed ging vibrations of CH 3Br.”

  Aliyev 等 - 2020 - SI-ATRP Polymer-Functionalized Graphene Oxide for DOI: 10.1002/admi.202000443.
• Amide confianza 1,0

  “Its presence interferes with the detection of the Amide III series of bands (1337, 1284, 1240 cm-1) and 1204 cm-1) but these would not be prominent in the perpendicular orientation.”

  Orientation Matters: Polarization Dependent IR Spectroscopy of Collagen from Intact Tendon Down to the Single Fibril Level DOI: 10.3390/molecules25184295
• confianza 1,0

  “Mcintosh et al.[7] had shown that the absorbance bands assigned to collagen (1035, 1080, 1204, cm-1) 1240, 1280, and 1330 were only observed in the dermis.”

  Hammody 等 - 2005 - Characterization of malignant melanoma using vibra DOI: 10.1100/tsw.2005.1
• Hydrogen bond confianza 1,0

  “electronic ground state were largely identical and gave limited Immediately after photoexcitation (Figure 2b, black line), information on the prevailing hydrogen bond patterns in these strong peaks appeared at 1204, 1258, 1284, 1349, 1386,”

  Spectroscopic and Computational Observation of Glutamine Tautomerization in the Blue Light Sensing Using Flavin Domain Photoreaction DOI: 10.1021/jacs.2c10621
• Hydroxyl (O-H) confianza 1,0

  “The C-O stretching and C-C stretching was detected at 1440 [27], cm-1 cm-1 C-N stretching at 1340 [21] and C-O stretching or O-H bending at 1204 [27].”

  Discrimination of Syzygium samarangense cv. ‘Giant Green’ Leaves at Different Maturity Stages by FTIR and GCMS Fingerprinting DOI: 10.3390/horticulturae9050609
• C-O single bond confianza 1,0

  “The very cm-1 wavenumbers correspond to C-F stretching vibrations of the PTFE strong absorption bands near 1144 and 1204 cm-1 are assigned to the symmetric vibrations of two ether backbone in Nafion.”

  Irmawati 等 - 2016 - Polarization Losses Under Dynamic Load Cycle Using DOI: 10.1063/1.4941635