What absorbs at 1699 cm⁻¹ in an FTIR spectrum?
A band near 1699 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 5 cited sources
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Alkyl C-H | 2 | 2 | 1.0 |
| Carboxyl (COOH) | 2 | 2 | 1.0 |
| Protein | 1 | 1 | 1.0 |
| Hydrogen bond | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
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Hydrogen bond confidence 1.0
“Moreover, the peaks at 1699 and 2KBrpellets.TheinteractionofwaterwithKBrmightshiftthepeak increasing temperature might be due to that the hydrogen bonds 3500cm-1”
Hsu 和 Lin - 2009 - Rapid examination of the kinetic process of intram DOI: 10.1016/j.tca.2008.12.008 -
Carboxyl (COOH) confidence 1.0
“2-HP-(cid:2)-CD-TEL × 19 July 2013 Received lenges, we have synthesized a complex with stability constant (Kc) of 2.39 The in revised form 5 September 2013 Received cm-1 2-HP-(cid:2)-CD-TEL absence in the FTIR spectrum of complex of the cha”
Telmisartan complex augments solubility, dissolution and drug delivery in prostate cancer cells DOI: 10.1016/j.carbpol.2013.09.077 -
Carboxyl (COOH) confidence 1.0
“LLM confirmed rule peak-group candidate”
Wang 等 - 2012 - Controlled network structure and its correlations DOI: 10.1039/c2ra00021k -
Protein confidence 1.0
“and (iv) the appearance of two IR bands According to Figure 5, the IR spectrum of protein G is dominated by two IR bands with maxima at 1699 and 1780 cm-1, both assigned to the C=O vibrational mode whose cm-1, at 1518 and 1634 which were as”
Optical Evidence for the Assembly of Sensors Based on Reduced Graphene Oxide and Polydiphenylamine for the Detection of Epidermal Growth Factor Receptor DOI: 10.3390/coatings11020258 -
Alkyl C-H confidence 1.0
“The spectra for amlodipine besylate drug (Figure 4b) show peaks at 2964.69 for C-CH stretching, at 1698.53,”
Formulation, optimization, and characterization of amlodipine besylate loaded polymeric nanoparticles DOI: 10.1177/09673911211056154
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