Water (H2O) — FTIR absorption peaks and assignments

Quick answer

Water (H2O) 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 Water (H2O)

Showing the 30 best-supported peaks of 734 total for Water (H2O).

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

• 3390 cm⁻¹ confidence 1.0

  “LLM confirmed rule peak-group candidate”

  Identification and properties of ion-pairs in the aqueous solutions of LiI and NaI by FTIR and quantum chemical calculations DOI: 10.1016/j.molliq.2020.114891
• 1993 cm⁻¹ confidence 1.0

  “Microstructure of extrudates & bonding forces thereby favoring water absorption (Lim Seib, 1993).”

  Encapsulating probiotics in novel resistant starch wall material for production of rice flour extrudates DOI: 10.1016/j.lwt.2020.110839
• 3258 cm⁻¹ confidence 1.0

  “hydroxyl group stretching is observed at 3258 This is due to the interaction of OH group in water by H bond which is observed as a stretching mode.”

  Synthesis and Characterization of Zinc Oxide Nanoparticles Using Acacia caesia Bark Extract and Its Photocatalytic and Antimicrobial Activities DOI: 10.3390/catal11121507
• 3418 cm⁻¹ confidence 1.0

  “The characteristic bands around 3418 are attributed to the presence of a small amount of water in the dried gel of YFeO 3.”

  Evolution of structure and improvement in dielectric properties of praseodymium substituted YFeO3 nanomaterials synthesized via a sol-gel auto-combustion method DOI: 10.1016/j.ceramint.2020.11.005
• 3400 cm⁻¹ confidence 1.0

  “The cm-1account bands around 3400 and 1630 for the presprominent The modes A 1g, B 1g, B and Eg are Raman active while A and 2g 2u ence of absorbed molecular water.”

  Effect of Mn doping on the structural and optical properties of SnO2 nanoparticles DOI: 10.1016/j.jallcom.2012.01.072
• 1417 cm⁻¹ confidence 1.0

  “The other bands at 1417 and 1414.21 corresponding to M-O-M bands The A cm-1 bond of H 2O molecule around 1627 is due to the presence of H-O-H vibration bending in water in M cm-1 belong to characteristic absorption peaks all samples before”

  Effect of rare earth and transition metal La-Mn substitution on electrical properties of co-precipitated M-type Ba-ferrites nanoparticles DOI: 10.1016/j.jre.2018.08.005
• 3345 cm⁻¹ confidence 1.0

  “- - 3430 3410 3393 3393 3374 3430 Alcohols / O-H strong & 3374 3374 3374 3374 3374 water stretching broad - - 3345 - - - - 3336 - - - - - 2961 2961 -”

  A fast and reliable 2D-IR spectroscopic technique for herbal leaves classification DOI: 10.1016/j.vibspec.2019.103014
• 1632 cm⁻¹ confidence 1.0

  “(mol%) cm(cid:0) 1 (vi) The intense peak at 1632 is related to vibrations of water,”

  Preparation and characterization of invert ZnO–B2O3 glasses and its shielding behavior towards gamma irradiation DOI: 10.1016/j.matchemphys.2019.122129