Ester — FTIR absorption peaks and assignments
These are the characteristic FTIR wavenumbers where Ester tends to absorb, compiled from published literature and ranked by supporting evidence. Each assignment is traceable to a source (DOI) and cross-validated against our 320,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
Ester 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 Ester
| Wavenumber (cm⁻¹) | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| 1740 | 110 | 97 | 1.0 |
| 1730 | 95 | 88 | 1.0 |
| 1735 | 77 | 75 | 1.0 |
| 1720 | 75 | 70 | 1.0 |
| 1700 | 69 | 64 | 1.0 |
| 1745 | 53 | 49 | 1.0 |
| 1650 | 52 | 50 | 1.0 |
| 1750 | 48 | 44 | 1.0 |
| 1743 | 40 | 38 | 1.0 |
| 1715 | 39 | 37 | 1.0 |
| 1640 | 36 | 34 | 1.0 |
| 1741 | 34 | 34 | 1.0 |
| 1630 | 34 | 32 | 1.0 |
| 1744 | 33 | 31 | 1.0 |
| 1725 | 32 | 29 | 1.0 |
| 1736 | 31 | 30 | 1.0 |
| 1600 | 30 | 29 | 1.0 |
| 1710 | 30 | 24 | 1.0 |
| 1738 | 29 | 29 | 1.0 |
| 1660 | 27 | 23 | 1.0 |
| 1732 | 26 | 24 | 1.0 |
| 1733 | 26 | 24 | 1.0 |
| 1728 | 26 | 23 | 1.0 |
| 1739 | 25 | 22 | 1.0 |
| 1726 | 24 | 24 | 1.0 |
| 1734 | 24 | 23 | 1.0 |
| 1737 | 23 | 21 | 1.0 |
| 1637 | 22 | 22 | 1.0 |
| 1722 | 22 | 20 | 1.0 |
| 1724 | 21 | 20 | 1.0 |
Showing the 30 best-supported peaks of 976 total for Ester.
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
-
1735 cm⁻¹ confidence 1.0
“The new peak appears cm-1 at 1735 which indicates the presence of a C=O bond from carboxylic acid.”
Synthesis and Physical Properties Characterization of Montmorillonite-modified Carbon Nanotubes Filler DOI: 10.1088/1757-899X/546/4/042004 -
1713 cm⁻¹ confidence 1.0
“This means that the addition shows sharp absorption and low intensity at 1712.8 cm-1 of DVB is able to shift the hydroxyl bonds in blends, which indicates the presence of C=O carbonyl so that DVB makes the blends more compatible.”
Grafting of Oleic Acid On Cyclic Natural Rubber Resiprene-35 Using Dicumyl Peroxide Initiator and Divinylbenzene Compatibilizers For Paint Binder In Polyamide Thermoplastics DOI: 10.13005/ojc/350119 -
1715 cm⁻¹ confidence 1.0
“are assigned to ester pectin polymer chains and the methyl group of the methyl ester The bands at 1715 and 1632 -COO(cid:0) CO-CH3”
Optimization of citron peel pectin and glycerol concentration in the production of edible film using response surface methodology DOI: 10.1016/j.heliyon.2023.e13724 -
1723 cm⁻¹ confidence 1.0
“The characteristics sharp peak at 1723 is attributed to stretching vibration of carbonyl (-C=O) group from GMSG/VMSG [46, 47], the intensity of which increases with the increase of GMSG/VMSG contents in the membrane”
Novel Silica Functionalized Monosodium Glutamate/PVA Cross-linked Membranes for Alkali Recovery by Diffusion Dialysis DOI: 10.21203/rs.3.rs-283846/v1 -
1723 cm⁻¹ confidence 1.0
“The other cm21 longed TC-HCl release, PHT-Na release behavior revealed that it peaks such as 1723 and 2941 corresponding to ester and can help the wound dressings to heal the wounds during 24 h carbon-hydrogen bonds in the chemical structur”
Three‐layered electrospun PVA/PCL/PVA nanofibrous mats containing tetracycline hydrochloride and phenytoin sodium: A case study on sustained control release, antibacterial, and cell culture properties DOI: 10.1002/app.43309 -
1746 cm⁻¹ confidence 1.0
“CO diesel is monitored by the ester stretch (1746 The impact of water on the precision of the biodiesel mixture is determined using a Karl Fischer titration to monitor water content.”
Quantitative Investigations of Biodiesel Fuel Using Infrared Spectroscopy: An Instrumental Analysis Experiment for Undergraduate Chemistry Students DOI: 10.1021/ed101097n -
1445 cm⁻¹ confidence 1.0
“N-C=O stretching at 1445 Other absorption On the other hand, it can be seen from Fig.”
Determination of iprodione in agrochemicals by infrared and Raman spectrometry DOI: 10.1007/s00216-007-1152-z -
1629 cm⁻¹ confidence 1.0
“The peak at 2922 3 cm-1 CEPTE 1629 is due to asymmetric stretching vibration of C=O carbonyl groups [28,29].”
Investigation on impedance response and dielectric relaxation of Ni-Zn ferrites prepared by self-combustion technique DOI: 10.1016/j.jallcom.2017.02.241
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