What absorbs at 1993 cm⁻¹ in an FTIR spectrum?
A band near 1993 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 4 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 2 | 2 | 1.0 |
| Ring structure | 1 | 1 | 1.0 |
| Water (H2O) | 1 | 1 | 1.0 |
| Ammonium | 1 | 0 | 1.0 |
| Alkyl C-H | 1 | 0 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
Water (H2O) confidence 1.0
“Microstructure of extrudates & bonding forces thereby favoring water absorption (Lim Seib, 1993).”
Encapsulating probiotics in novel resistant starch wall material for production of rice flour extrudates DOI: 10.1016/j.lwt.2020.110839 -
Hydroxyl (O-H) confidence 1.0
“(1993), the OH-stretching wavenumber below 3750 is”
Temperature dependence of IR absorption of OH species in clinopyroxene DOI: 10.2138/am.2010.3501 -
Hydroxyl (O-H) confidence 1.0
“This is attributed to the complex vibrational stretching GernatC(1993)Crystallinepartsofthreedifferentconformationsdetectassociated with free, inter and intra molecular bound hydroxyl ed in nativeand enzymaticallydegraded starches.Starch-St”
Jivan 等 - 2014 - Preparation of cold water-soluble potato starch an DOI: 10.1007/s13197-013-1200-y -
Ring structure confidence 1.0
“This caused unique features of the polymer PSandPEO,CHstretchingofthemainchainofPS,andaromatic filler composites with each in terms of the crystallinity, the ring vibrations (Jabbari and Peppas, 1993).”
Kim 等 - 2020 - Lithium Salt Dissociation in Diblock Copolymer Ele DOI: 10.3389/fenrg.2020.569442
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