What absorbs at 1805 cm⁻¹ in an FTIR spectrum?
A band near 1805 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 |
|---|---|---|---|
| N-O bond | 2 | 2 | 1.0 |
| Hydroxyl (O-H) | 1 | 1 | 1.0 |
| Carbonate | 1 | 1 | 1.0 |
| Alkene (C=C) | 1 | 1 | 1.0 |
| Carbonyl (C=O) | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
-
confidence 1.0
“In particular, addition of 14 cm-1 O to NO slightly increases the amount of Pd(II)-NO complex with ν at ~1865 whereas 15 2 NO 16 cm-1, the low frequency ν band at 1805 assigned to Pd(I)-NO, decreases in intensity.”
Molecular Level Understanding of How Oxygen and Carbon Monoxide Improve NOx Storage in Palladium/SSZ-13 Passive NOx Adsorbers: The Role of NO+ and Pd(II)(CO)(NO) Species DOI: 10.1021/acs.jpcc.8b01007 -
Carbonyl (C=O) confidence 1.0
“a consistent amount of ethylene carbonate (EC) is obtained, as cm-1 testified by the presence of a doublet of bands at 1805 and cm-1 1774 that can be easily ascribed to the combined carbonyl stretching modes of the ethylene carbonate.”
Dani 等 - 2015 - Design of high surface area poly(ionic liquid)s to DOI: 10.1039/c5ta00272a -
N-O bond confidence 1.0
“In this case a cm(cid:2)1 new band appears at 1805 corresponds to gas phase NO.”
Diaz Consul 等 - 2008 - NO reduction with CO on alumina-modified silica-su DOI: 10.1016/j.apcata.2008.01.022 -
Hydroxyl (O-H) confidence 1.0
“1409-1460 C = O (Asymetric stretching) O-H (Bending) 1805 Vibrations of carbonate ions 2512 C = O from calcite”
da Silva 和 Wiebeck - 2022 - ATR-FTIR Spectroscopy Combined with Chemometric Me DOI: 10.21203/rs.3.rs-905784/v1 -
confidence 0.9
“band around ~1805 cm-1 for Pd/SSZ-13 belonged to Pd(I)-NO”
The superior hydrothermal stability of Pd/SSZ-39 in low temperature passive NOx adsorption (PNA) and methane combustion DOI: 10.1016/j.jcat.2010.07.031.
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