What absorbs at 1159 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 1159 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 fixed 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 1159 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

  “at 3291 -OH and -NH groups, 2922-OH stretching, 1745-carboxyl and carbonyl groups of 2 hemicellulose, 1650amide (-C=O) or N-H bending, 1513-aromatic skeletal vibrations, 1457-OH and -C-O stretching, 1232-C-O stretch, 1159-C-O stretching of”

  Adsorption Kinetic and Isotherms of Reactive Red 120 on <i>Moringa oleifera</i> Seed as an Eco-Friendly Process DOI: 10.1016/j.molstruc.2019.05.106
• Nucleic acid confidence 1.0

  “2- (] asymmetric stretching (PO )) Nucleic acid PO as (] C-O stretching (C-O)) 1159 Protein/CarbohydrateLipid”

  Ferreira 等 - 2020 - Attenuated Total Reflection-Fourier Transform Infr DOI: 10.1155/2020/4343590
• Acetate confidence 1.0

  “cm-1 cm-1 1256 (C-H bending and CH symmetrical deformation), 1069 (asymmetric 3 cm-1 in-phase ring-stretching mode), 1023 (C-O-C asymmetric in-phase ring-stretching), 1159cm-1 1114cm-1”

  Antimicrobial Activity of Chemically and Biologically Treated Chitosan Prepared from Black Soldier Fly (Hermetia illucens) Pupal Shell Waste DOI: 10.3390/microorganisms9122417
• confidence 1.0

  “Hþ and that of the amine band from to is produced through the dissociation of acid as inferred from the existence of the bands 1159cm(cid:1)1.”

  Majid 和 Arof - 2008 - FTIR studies of chitosan-orthophosphoric acid-ammo DOI: 10.1080/15421400801904286
• Silicon (Si) confidence 1.0

  “The important absorption cm-1 band appearing at 1159 was assigned to Si-O-C,”

  Thermal, Rheological, Mechanical and Morphological Behavior of High Density Polyethylene and Carboxymethyl Cellulose Blend DOI: 10.1007/s10924-016-0880-6
• Alkyl C-H confidence 1.0

  “ging mode at The peaks at 2951, 1721, 1449 and 1159cm-1 are assigned to CH stretching, C O stretching, CH 3 stretching and O CH stretching vibrations, respectively, in 3 Fig.5.”

  Ramesh 等 - 2007 - FTIR studies of PVCPMMA blend based polymer elect DOI: 10.1016/j.saa.2006.06.012
• Aromatic ring confidence 1.0

  “The band at 1159 out-of-plane bending vibrations in the aromatic ring.”

  Efficient removal of Cr(VI) by polyaniline modified biochar from date (Phoenix dactylifera) seed DOI: 10.1016/j.gsd.2021.100653
• Acetate confidence 1.0

  “The 2 -1 creasing ultrasonic intensity because the higher ultrasonic intensity peaks at 1159, 1052, and 1027 cm were attributed to the C-O-C produced the more hydrodynamic shear force and more numbers antisymmetric vibration of cellulose an”

  Fast and practical synthesis of carboxymethyl cellulose from office paper waste by ultrasonic-assisted technique at ambient temperature DOI: 10.1016/j.polymdegradstab.2020.109473