Imide — FTIR absorption peaks and assignments

Quick answer

Imide 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 Imide

Showing the 30 best-supported peaks of 56 total for Imide.

Possible materials

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

• 1722 cm⁻¹ confidence 1.0

  “All band at position 1722 these changes may be due to the partial destruction at the imide and aromatic sites and carbonization of the implanted layer of Kapton-H.”

  Chhokkar 等 - 2020 - Electrical and Structural Characterization of 100 DOI: 10.1063/5.0023335
• 1779 cm⁻¹ confidence 1.0

  “the unaged CBR 320/328 composites reveal three imide carbonyl peaks at 1779, 1728 and 1712 These peaks may be assigned to the symmetric and asymmetric stretches of an unsaturated imide (1779 and 1728 cm(cid:2)1)”

  Fox 等 - 2004 - Investigation of failure mechanisms in aged aerosp DOI: 10.1016/j.engfailanal.2003.05.010
• 1501 cm⁻¹ confidence 1.0

  “1376-cm(cid:2)1 the imide band normalized to the 1501gion.”

  Studies on the photodegradation of polarized UV-exposed PMDA-ODA polyimide films DOI: 10.1002/app.11315
• 1724 cm⁻¹ confidence 1.0

  “hr, the 1 in 2(b), shown Figure after hard baking at 275°C for As 1724 characteristic imide peaks appeared at 1780, and 1375cm-I.”

  Ha 等 - 1998 - Polarized Infrared Spectroscopic Studies of Polari DOI: 10.1080/10587259808025380
• 1778 cm⁻¹ confidence 1.0

  “1H FT-IR spectrum of this aromatic copolyanalyzing the NMR spectrum of imide (Figure 5) presents imide carbonyl PAA-A, the conclusion is drawn that a cm(cid:2)1, peaks at around 1778 and 1723 singlet at 6.63 ppm is assigned to the and -NHCO”

  Preparation of Poly(amic acid) and Polyimide via Microwave-Assisted Polycondensation of Aromatic Dianhydrides and Diamines DOI: 10.1002/masy.200850120
• 3172 cm⁻¹ confidence 1.0

  “that could not be assigned to known elements and do not The amide peaks at 3314, 3259, 2079(broad), 1567, and cmL1and correspondtoanyotherprimaryelementpeak.The10.8eV, the imide peaks at 3172 (broad), 1953, and 1541 HL(1/4)”

  Mills 等 - 2009 - Commercializable power source from forming new sta DOI: 10.1016/j.ijhydene.2008.10.018
• 738 cm⁻¹ confidence 1.0

  “explicit assignment”

  Purushothaman 和 Bilal - 2014 - Development and characterization of homo, co and t DOI: 10.1515/polyeng-2013-0167
• 400 cm⁻¹ confidence 1.0

  “peaks between 400 and 700 Due to the conversion of a secondary amine into a stable cm-1 imide (C=N) bond, AF exhibits the majority of its characteristic peaks at 1640 [76].”

  Molecularly Targeted Photothermal Ablation of Epidermal Growth Factor Receptor-Expressing Cancer Cells with a Polypyrrole–Iron Oxide–Afatinib Nanocomposite DOI: 10.3390/cancers14205043