What absorbs at 2907 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 2907 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 authoritative 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 2907 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

• Acetate confidence 1.0

  “on 1412 CH2, CH3 bending Acid phosphatase [31, 35] 16 Island 1447 CH2, CH3 bending Tryptophane [31] It is worth mention that the peaks at 2907 and 2968 17 1667 Amide I Protein [27] cm-1 haven't been characterized and discussed in”

  Zou 等 - 2016 - Whole blood and semen identification using mid-inf DOI: 10.1039/C5AY03337C.
• Alkyl C-H confidence 1.0

  “For AD-rhEPO, the cm-1 alone.Theseresultswereinaccordancewiththeresultsreband at 2907.3 represents the -C-H groups of AD, and cm-1”

  Application of SPRA Technology for Delivery of Erythropoietin: Stability Evaluation of Conjugated Erythropoietin with Adamantane and in SPRA Inclusion Complex DOI: 10.5812/ijpr-134282.
• Alkyl C-H confidence 1.0

  “The mecm(cid:2)1 cm(cid:2)1 dium band at 2944 with shoulder at 2907 can be assigned to the stretchcm(cid:2)1 ing vibrations of CH 2.”

  Synthesis, crystal structure, and characterization of cyclohexylammonium tetraisothiocyanatocobaltate(II): A single-source precursor for cobalt sulfide and oxide nanostructures DOI: 10.1016/j.heliyon.2019.
• Alkyl C-H confidence 1.0

  “Adcm-1 ditionally, there are two bands at 2907 and 1402 which attributed to C-H stretching vibration and in-plane respectively31.”

  Fabrication of attapulgite/magnetic aminated chitosan composite as efficient and reusable adsorbent for Cr (VI) ions DOI: 10.1038/s41598-021-96145-6
• Alkyl C-H confidence 1.0

  “N-H the broadband at 3244 shifting of this band was accentuated as the LiClO is attributed to the 4 stretching.79 cm-1 The absorbance band at 2907 is associated concentration increased, which seems to suggest an interaction OHLi+ C-H with s”

  Gurumendi 等 - 2023 - Enhanced Chitosan Photoluminescence by Incorporati DOI: 10.1021/acsomega.2c08072
• Alkyl C-H confidence 1.0

  “2963, 2907 cm-1 cm-1 and 2873 were the stretching vibration absorption peaks of saturated C-H, 1730 was the stretching”

  Terpolymer resin containing bioinspired borneol and controlled release of camphor: Synthesis and antifouling coating application DOI: 10.1038/s41598-020-67073-8
• Alkyl C-H confidence 1.0

  “The peaks that appeared at 2937 cm-1 and 2907 cm-1 were due to the symmetric and asymmetric stretching vibration peaks of methylene [46].”

  Preparation of a Cation Exchange Membrane by a Sol-Gel Method-Based Polyvinyl Alcohol to Improve Alkali Recovery via Diffusion Dialysis in the Textile Industry DOI: 10.3390/separations10070370
• Alkyl C-H confidence 0.9

  “Stretching vibrations of C-H.”

  Fungal Biodeterioration of a Historical Manuscript Dating Back to the 14th Century: An Insight into Various Fungal Strains and Their Enzymatic Activities DOI: 10.3390/life12111821