What absorbs at 701 cm⁻¹ in an FTIR spectrum?

Quick answer

A band near 701 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 701 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

• confidence 1.0

  “g-Al SbCl spectrum, in addition to 2O signal, two additional 5 3 g-Al band at 701 show binding of SbCl to 2O 3.”

  Bamoniri 等 - 2018 - Nano-gamma-Al2O3SbCl5 an efficient catalyst for DOI: 10.1039/c7ra13593a
• Hydroxyl (O-H) confidence 1.0

  “cm-1 Two bands at 701 and 670 typically represent, in the case of cell wall material, H-bonded O-H out-of-plane bending vibrations of cellulose [47,48].”

  Bednarek 等 - 2020 - Exploring the Biochemical Origin of DNA Sequence V DOI: 10.3390/ijms21165770
• confidence 1.0

  “7c, 2 cm-1 the peak at 701 is assigned to N-H swaging on both primary and secondary amines [33].”

  Growth and organization of (3-Trimethoxysilylpropyl) diethylenetriamine within reactive amino-terminated self-assembled monolayer on silica DOI: 10.1016/S0079-6816(00)00024-1.
• Aromatic ring confidence 1.0

  “Among the cm-1 biocomposites with styrene (Figure S1c, Supplementary Materials), a band at 701 due to the bending of the aromatic carbon-hydrogen bonds of styrene was also observed [62].”

  Preparation, Thermal, and Mechanical Characterization of UV-Cured Polymer Biocomposites with Lignin DOI: 10.3390/polym12051159
• Metal oxygen confidence 1.0

  “blended ZSM-5 zeolite composite samples show their typcm-1 is related to stretching vibrations of of new peak at 670 and ZSM-5 ical XRD peaks corresponding to ZnO, TiO 2 701cm-1 shifts at higher energy Zn-O bond [24] and peak at host.”

  Lakhane 等 - 2016 - Metal oxide blended ZSM-5 nanocomposites as ethano DOI: 10.1007/s12034-016-1286-8
• Carbonate confidence 1.0

  “10 cm-1 The bands posited at 701, 1383-1387 can be • 470 05 assigned to the presence of calcite or aragonite.”

  Radev 等 - 2012 - In vitro bioactivity of 70 wt.% SiO2-30 wt.% CaO s DOI: 10.2478/s11532-011-0129-0
• Hydroxyl (O-H) confidence 1.0

  “the surface OH groups near 936 the surface hydroxyls are associated with additional bands near 701 and cm-1.”

  The production of biodiesel from plum waste oil using nano-structured catalyst loaded into supports DOI: 10.1038/s41598-021-03633-w
• confidence 1.0

  “470.1493 Si-O bending, Si-O-Fe stretching 530.5970 Si-O bending, Si-O-Al stretching 700.7463 Si-O stretching, Si-O-Al stretching”

  Structural Study of Nano-Clay and Its Effectiveness in Radiation Protection against X-rays DOI: 10.3390/nano12142332