What absorbs at 1229 cm⁻¹ in an FTIR spectrum?
A band near 1229 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
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| C-O single bond | 9 | 9 | 1.0 |
| Methacrylate | 9 | 9 | 1.0 |
| Acetate | 9 | 9 | 1.0 |
| Methoxy (OCH3) | 8 | 8 | 1.0 |
| Amide | 4 | 4 | 1.0 |
| Hydroxyl (O-H) | 3 | 3 | 1.0 |
| Alkyl C-H | 2 | 2 | 1.0 |
| Secondary amine | 2 | 2 | 1.0 |
| C n single bond | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Carbonyl (C=O) | 2 | 2 | 1.0 |
| C c single bond | 1 | 1 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Bromine | 1 | 1 | 1.0 |
| Carbon bromine | 1 | 1 | 1.0 |
| Ketone | 1 | 1 | 1.0 |
| Ester | 1 | 1 | 1.0 |
| Urethane | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Hydroxyl (O-H) confidence 1.0
“of peak changes in wavenumber for alginate-GA in BBPEs system (cm-1) Assignments (functional group) Wavenumber GA ALGAALGAALGAALGAALGAALGAALGA0 1 2 3 4 5 6 - C-O-C 1025 1030 1031 1035 1035 1080 1081 stretching - - - - - - - 1074 C-O stretch”
Enhancing proton conductivity of sodium alginate doped with glycolic acid in bio-based polymer electrolytes system DOI: 10.1007/s10965-020-02142-0 -
Acetate confidence 1.0
“Meanwhile, the peaks at 1229 and 1070 are assigned to C-O and C-O-C stretching vibrations cm-1 from urethane carbonyl.”
Preparation of one-shot and two-shot method of semi-rigid polyurethane film based on functionalized liquid natural rubber DOI: 10.1063/1.5047200 -
Acetate confidence 1.0
“The bands at 1229 and cm-1 samples was examined immediately after the sam1062 are assigned to C-O and C-O-C stretching ples were removed from the media before they were vibrations from urethane carbonyl [9].”
The behavior of semi-rigid polyurethane film based on functionalized rubber by one-shot and two-shot method preparation DOI: 10.1007/s10853-018-2578-8 -
Carboxyl (COOH) confidence 1.0
“The degree of stretching vibration mode of the carboxylic group (C-O) corresponding to the peaks at 1229, 1217, 1215, 1073, cm-1 1071 and 1068 of all as-burnt BCZT powders decreased with increasing pH value.”
Influence of pH values on the surface and properties of BCZT nanopowders synthesized via sol-gel auto-combustion method DOI: 10.1016/j.surfcoat.2016.03.091 -
C-O single bond confidence 1.0
“LLM confirmed rule peak-group candidate”
Graphene oxide-TiO2 and reduced graphene oxide-TiO2 nanocomposites: Insight in charge-carrier lifetime measurements DOI: 10.1016/j.cattod.2016.11.008 -
confidence 1.0
“cm(cid:0) C-- 1, 8400 automatic nitrogen determination apparatus (FOSS, Hiller, which correspond to the O stretching vibra1229, and 1059 C(cid:0) (cid:0) (cid:0) C(cid:0) O(cid:0) Denmark) in the Kjeldahl mode.”
Preparation of pH-sensitive polylactic acid-naringin coaxial electrospun fiber membranes for maintaining and monitoring salmon freshness DOI: 10.1016/j.ijbiomac.2021.08.087 -
Acetate confidence 1.0
“hydrogen bonded hydroxyl groups (3600-3200 cm-1 The standard has a very strong band at 1737 that is assigned to C=O cm-1 that corresponds to in-plane stretching of COOH group and a band at 1229 bending vibrations of OH groups from COOH (Fig”
Miletic 等 - 2020 - Oxidized humic acids from the soil of heat power p DOI: 10.2298/JSC190726099M -
Amide confidence 1.0
“LLM confirmed rule peak-group candidate”
Direct Quantification of Drug Loading Content in Polymeric Nanoparticles by Infrared Spectroscopy DOI: 10.3390/pharmaceutics12100912
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