What absorbs at 1312 cm⁻¹ in an FTIR spectrum?
A band near 1312 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 8 cited sources
Quick answer
A band near 1312 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
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Amide | 7 | 5 | 1.0 |
| Secondary amine | 4 | 2 | 1.0 |
| C n single bond | 4 | 2 | 1.0 |
| Methoxy (OCH3) | 3 | 3 | 1.0 |
| Methacrylate | 3 | 3 | 1.0 |
| C-O single bond | 3 | 3 | 1.0 |
| Acetate | 3 | 3 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Lipid | 1 | 1 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| polydopamine | 1312, 1543, 1707 | Methoxy (OCH3), Amide | 1 |
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 1312 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
-
Amide confidence 1.0
“The 1312cm-1 1026cm-1 band observed at and are corresponding to C-N”
Co-pyrolysis of rice straw and water hyacinth_ Characterization of products, yields and biomass interaction effect DOI: 10.1016/j.biombioe.2019.105281 -
Amide confidence 1.0
“A well-defined amide II band cm(cid:0) cm(cid:0) 1 1 (C-N at 1515 (tyrosine) and a small amide III band at 1312”
Organic biopolymers of venus clams: Collagen-related matrix in the bivalve shells with crossed-lamellar ultrastructure DOI: 10.1016/j.bbrep.2021.100939 -
C c single bond confidence 1.0
“ester C-C-O stretch 1312 1343”
Comprehensive analytical and structural characteristics of methyl 3,3-dimethyl-2-(1-(pent-4-en-1-yl)-1H-indazole-3-carboxamido)butanoate (MDMB-4en-PINACA) DOI: 10.1007/s11419-021-00573-y -
Acetate confidence 1.0
“another additional peak at 1312.27 corresponds to the C-O cm-1 corresponds to the C-O bonds in dopamine molecule that verifies the dopamine addition on 691.17 cm-1 corresponds to the Ce-O stretching vibrations [11];”
Synthesis of Lipase-Immobilized CeO2 Nanorods as Heterogeneous Nano-Biocatalyst for Optimized Biodiesel Production from Eruca sativa Seed Oil DOI: 10.3390/catal10020231 -
Amide confidence 1.0
“976 cm-1, cm-1, bands around 1600 and minor amide III and V bands around 1312 and 690 respectively.”
The affiliation of Hexasterias problematica and Halodinium verrucatum sp. nov. to ciliate cysts based on molecular phylogeny and cyst wall composition DOI: 10.1016/j.ejop.2018.09.002 -
Alkyl C-H confidence 1.0
“The bands at 1429 and 1312 cm-1 can be attributed to symmetric angular strain in the plane of the CH2 group and symmetrical angular strain in the plane of the CH2 groups, respectively.”
Impact and Tensile Properties of Polyester Nanocomposites Reinforced with Conifer Fiber Cellulose Nanocrystal:A Previous Study Extension DOI: 10.3390/polym13111878 -
Amide confidence 1.0
“Amide III stretching Phospholipids (v) 1312 CH2 3.1.”
Label-Free Discrimination Analysis of De-Differentiated Vascular Smooth Muscle Cells, Mesenchymal Stem Cells and Their Vascular and Osteogenic Progeny Using Vibrational Spectroscopy DOI: 10.1016/j.bbamcr.2017.11.006 -
Amide confidence 1.0
“1382 shifted to 1385 Furthermore, cm-1 ν(C-N) the peak intensity of DH at 1312 cm-1 decreased and shifted to a weak band at 1309”
Somphon 和 Makatan - 2019 - Characterization of donepezil prepared by cogrindi DOI: 10.2306/scienceasia1513-1874.2019.45.028
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