What absorbs at 689 cm⁻¹ in an FTIR spectrum?
A band near 689 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 3 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Aromatic ring | 1 | 1 | 1.0 |
| Borate | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Metal oxygen | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Carbonate confidence 1.0
“Thus, the 715 1 cm-1 m and 689 carbonate peaks we observed are consis4 tent with B-type carbonated apatite.”
Awonusi 等 - 2007 - Carbonate assignment and calibration in the raman DOI: 10.1007/s00223-007-9034-0 -
Borate confidence 1.0
“Kamitsos EI (2003) Phys Chem Glasses 44:79-87 is attributed to B - O - B (b) The peaks at 689”
Gamma Irradiation Effect on Structural and Spectral Properties of CeO 2, Nd 2O3, Gd 2O3 or Dy 2O3 – Doped Strontium Borate Glass DOI: 10.1007/s12633-017-9622-1 -
Aromatic ring confidence 1.0
“In the same range of 1905 the overtones cm-1 mono-substitution meta di-substitution due to (coupled with the 689 band) and (coupled cm-1 Aromatic compounds with the 864 band) were also identified.”
The Origin and Physico-Chemical Properties of Some Unusual Earth Rock Fragments DOI: 10.3390/app12030983
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