Dr. Dietmar Kennepohl FCIC (Professor of Chemistry, Athabasca University), Prof. Steven Farmer (Sonoma State University), William Reusch, Professor Emeritus (Michigan State U. Alcohol/Phenol O-H Stretch: 3550 - 3200 (broad, s) See "Free vs. Hyrdogen-Bonded Hydroxyl Groups" in the Introduction to IR Spectra for more information: Carboxylic Acid O-H Stretch: 3000 - 2500 (broad, v) Amine N-H Stretch: 3500 - 3300 (m) Primary amines produce two N-H stretch absorptions, secondary amides only one, and tetriary none. These are summarized in the following diagram, where the green shaded box at the top displays examples of such "localized" molecular ions. For example: The problem seems to be that the position of the -OH peak varies dramatically depending on the conditions - for example, what solvent is used, the concentration, and the purity of the alcohol - especially on whether or not it is totally dry. You can ignore the effect of the -OH hydrogen. A reliable degree level organic chemistry text book quotes1.0 - 5.0, but then shows an NMR spectrum for ethanol with a peak at about 6.1. Ethyl Alcohol, Pure, 190 Proof, HPLC Grade All HPLC and Ultra-pure solvents offered by MilliporeSigma are glass distilled, submicron filtered, and undergo rigorous specification testing to insure accurate, repeatable results. IR spectrum of 1-butanol. Reference standards are particularly important for analytical chemistry since most analytical instrumentation is comparative; it requires a sample of known. The OCR Data Sheet for use in their exams quotes 3.5 - 5.5. The Nuffield Data Book quotes 2.0 - 4.0, but the Nuffield text book shows a peak at about 5.4. It is also the liquid in some thermometers. ATR-FT-IR spectra of conservation-related materials in the MID-IR and FAR-IR region. Unless otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. Where is the -O-H peak? We manufacture and distribute fine chemicals and laboratory products - with quality and delivery you can count on every time. Instead of seeing one sharp peak, you see a whole lot of them all smeared out into one broad blob. Unless the alcohol is absolutely free of any water, the hydrogen on the -OH group and any hydrogens on the next door carbon don't interact to produce any splitting. Home; Paint components . From mass spectroscopy analysis it was determined that a compound has the general formula C5H12O. Specifications, HPLC Grade, Reagent Alcohol, Denatured, Histological Grade, Ethyl Alcohol, Pure, 190 Proof, HPLC Grade, Dehydrated Alcohol, 200 Proof, Undenatured, USP, Ethyl Alcohol, Absolute, 200 Proof, Reagent, ACS, Dehydrated Alcohol, 200 Proof, USP, EP, BP. For the traditional method of calibrating the ratio of integrated band intensities of the CH and OH stretching regions it is found that narrowing the spectral window of the CH stretch can significantly improve the measurement sensitivity. For a simplistic approach based on the Beer–Lambert relation, an optimized set of parameters for quantitative measurements are determined. predict the general form (i.e., number of peaks, approximate chemical shifts, and splitting pattern) of the proton NMR of a given alcohol or phenol. Upon first inspection, a typical infrared spectrum can be visually divided into two regions. there is a strong C-O stretching mode near 1000 cm-1.