What absorbs at 1742 cm⁻¹ in an FTIR spectrum?
A band near 1742 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
ਤੁਰੰਤ ਜਵਾਬ
A band near 1742 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.
ਸੰਭਾਵਿਤ ਫੰਕਸ਼ਨਲ-ਗਰੁੱਪ ਅਸਾਈਨਮੈਂਟਾਂ
| ਫੰਕਸ਼ਨਲ ਗਰੁੱਪ | ਸਹਾਇਕ ਤੱਥ | ਹਵਾਲਾ ਦਿੱਤੇ ਸਰੋਤ | ਉੱਚ ਵਿਸ਼ਵਾਸ |
|---|---|---|---|
| Carbonyl (C=O) | 28 | 25 | 1.0 |
| Ester | 20 | 17 | 1.0 |
| Carboxyl (COOH) | 16 | 14 | 1.0 |
| Methacrylate | 14 | 12 | 1.0 |
| Acetate | 14 | 12 | 1.0 |
| Ketone | 13 | 11 | 1.0 |
| Amide | 13 | 11 | 1.0 |
| Alkyl C-H | 6 | 6 | 1.0 |
| Lipid | 4 | 4 | 1.0 |
| Methoxy (OCH3) | 2 | 2 | 1.0 |
| Carbohydrate | 2 | 2 | 1.0 |
| N h | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Aldehyde (CHO) | 1 | 1 | 1.0 |
| C-O single bond | 1 | 1 | 1.0 |
| Acetyl | 1 | 1 | 1.0 |
| Methyl | 1 | 1 | 1.0 |
ਰੈਂਕਿੰਗ ਸੰਚਿਤ ਸਾਹਿਤ ਸਬੂਤਾਂ ਨੂੰ ਦਰਸਾਉਂਦੀ ਹੈ, ਇੱਕ ਸਿੰਗਲ ਅਧਿਕਾਰਤ ਨਿਯਮ ਨਹੀਂ। ਹਮੇਸ਼ਾਂ ਆਪਣੇ ਨਮੂਨੇ ਦੇ ਸੰਦਰਭ ਦੇ ਵਿਰੁੱਧ ਪੁਸ਼ਟੀ ਕਰੋ।
ਸਪੈਕਟ੍ਰਮ ਤਰਕ
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 1742 cm⁻¹ is usually not enough for material identification by itself.
ਅਸਲ-ਸੰਸਾਰ ਵਰਤੋਂ
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
ਆਮ ਗਲਤੀਆਂ
- ਘੱਟੋ-ਘੱਟ ਇੱਕ ਜਾਂ ਦੋ ਸਹਾਇਕ ਚੋਟੀਆਂ ਦੀ ਜਾਂਚ ਕੀਤੇ ਬਿਨਾਂ ਇੱਕ ਅਲੱਗ-ਥਲੱਗ ਬੈਂਡ ਨੂੰ ਸਮੱਗਰੀ ਦੇ ਸਬੂਤ ਵਜੋਂ ਮੰਨਣਾ।
- ਓਵਰਲੈਪ ਨੂੰ ਨਜ਼ਰਅੰਦਾਜ਼ ਕਰਦੇ ਹੋਏ: ਕਈ ਕਾਰਜਸ਼ੀਲ ਸਮੂਹ ਇੱਕੋ ਵੇਵਨੰਬਰ ਦੇ ਨੇੜੇ ਯੋਗਦਾਨ ਪਾ ਸਕਦੇ ਹਨ।
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
ਤਸਦੀਕ ਸਲਾਹ
ਜਦੋਂ ਅਸਪਸ਼ਟਤਾ ਬਣੀ ਰਹਿੰਦੀ ਹੈ, ਤਾਂ DSC, GC-MS, ਜਾਂ TGA ਨਾਲ ਪਰਿਕਲਪਨਾ ਦੀ ਪੁਸ਼ਟੀ ਕਰੋ, ਖਾਸ ਕਰਕੇ ਮਿਸ਼ਰਣਾਂ, ਵਿਗੜੇ ਹੋਏ ਨਮੂਨਿਆਂ ਅਤੇ ਭਰੇ ਹੋਏ ਪੌਲੀਮਰਾਂ ਲਈ।
ਇਹਨਾਂ ਅਸਾਈਨਮੈਂਟਾਂ ਪਿੱਛੇ ਸਾਹਿਤ
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Ester ਵਿਸ਼ਵਾਸ 1.0
“They show a series of characteristic bands that are split into three bands around 1686, The FT-IR spectrum of electrospun PHB fibers and their blends are shown in Figure 9 at different 1723, and 1742 cm-1, which correspond to the ester carb”
Influence of Electrospinning Parameters on Fiber Diameter and Mechanical Properties of Poly(3-Hydroxybutyrate) (PHB) and Polyanilines (PANI) Blends DOI: 10.3390/polym8030097 -
Lipid ਵਿਸ਼ਵਾਸ 1.0
“In the vicinity of 1800~1400 187 cm-1 there were three important lipid peak at 1742, 1654, and 1438 relating to C=O 188 stretching, C=C stretching, and C-H scissoring deformation respectively.”
Gao 等 - 2021 - Complementarity of FT-IR and Raman spectroscopies DOI: 10.1016/j.foodchem.2020.128754 -
Carbonyl (C=O) ਵਿਸ਼ਵਾਸ 1.0
“Reducing the intensity of the peaks at 1742 and 1629 in FT-IR spectrum of the nanofibers indicates resistance of carbonyl groups against more vibration due to interactions with aluminum ions.”
Ghayempour 和 Montazer - 2018 - A modified microemulsion method for fabrication of DOI: 10.1016/j.ijbiomac.2018.04.037 -
Carboxyl (COOH) ਵਿਸ਼ਵਾਸ 1.0
“cm-1 The pH-independent component is associated with a trough around the 1742 band attributable to one or more protonated carboxylic acids.”
Iwaki 和 Rich - 2007 - An IR study of protonation changes associated with DOI: 10.1021/ja067779i -
Acetate ਵਿਸ਼ਵਾਸ 1.0
“In the spectrum of GG-g-Poly(DMAEMA)-1 156 Accepted cm-1 (Fig.2b), in addition to the peaks mentioned above, new peaks appeared at 1742 and 157 cm-1 2630 attributed to C=O stretching of carboxylic ester and C-H stretching of -N(CH 3)”
Novel stimuli - responsive gellan gum - graft - poly(DMAEMA) hydrogel as adsorbent for anionic dye DOI: 10.1016/j.ijbiomac.2015.08.064 -
Lipid ਵਿਸ਼ਵਾਸ 1.0
“since a higher absorbance of lipid bands at 1742, 1466, 1236, and [26] G.M.”
Rapid approach to analyze biochemical variation in rat organs by ATR FTIR spectroscopy DOI: 10.1016/j.saa.2013.09.131 -
Carbohydrate ਵਿਸ਼ਵਾਸ 1.0
“incorporated into the cellulose chains after esterification is assigned at 1742 The vibration at 1061 C-O-C O-H cm-1 can be elucidated for the stretching of and of polysaccharides.”
Ulfa 等 - 2019 - Adsorption of Cu(II) in Aqueous Solution by Modifi DOI: 10.1088/1755-1315/239/1/012008 -
Ester ਵਿਸ਼ਵਾਸ 1.0
“A shoulder band C=O at 1742 was observed due to conjugation of ester-groups which occurs during the 1 3 56 A.”
Garden cress gum and maltodextrin as microencapsulation coats for entrapment of garden cress phenolic-rich extract: improved thermal stability, storage stability, antioxidant and antibacterial activities DOI: 10.1007/s10068-022-01171-3
ਕੀ ਇਸ ਬੈਂਡ ਨਾਲ ਇੱਕ ਸਪੈਕਟ੍ਰਮ ਹੈ?
ਆਪਣਾ FTIR ਸਪੈਕਟ੍ਰਮ ਅੱਪਲੋਡ ਕਰੋ ਅਤੇ ਸਕਿੰਟਾਂ ਵਿੱਚ ਇੱਕ ਪੂਰੀ ਵਿਆਖਿਆ ਰਿਪੋਰਟ ਪ੍ਰਾਪਤ ਕਰੋ — ਪੀਕ ਅਸਾਈਨਮੈਂਟਾਂ, ਲਾਇਬ੍ਰੇਰੀ ਮੈਚ, ਅਤੇ ਇੱਕ ਵਿਸ਼ਵਾਸ-ਦਰਜਾ ਪ੍ਰਾਪਤ ਸਬੂਤ ਲੜੀ।