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Pinacol is a branched alcohol which finds use in organic syntheses. It is a diol that has hydroxyl groups on vicinal carbon atoms. A white solid that melts just above room temperature, pinacol is notable for undergoing the pinacol rearrangement in the presence of acid and for being the namesake of the pinacol coupling reaction.
Pinacolyl alcohol (also known as 3,3-dimethylbutan-2-ol and as pine alcohol) is one of the isomeric hexanols and a secondary alcohol. Pinacolyl alcohol appears on the List of Schedule 2 substances of the Chemical Weapons Convention as a precursor for the nerve agent soman .
If a spectrum of an unknown chemical compound is available, a reverse search can be carried out by entering the values of the chemical shift, frequency or mass of the peaks in the NMR, FT-IR or EI-MS spectrum respectively. This type of search affords all the chemical compounds in the database that have the entered spectral characteristics. [6]
SDBS includes 14700 1 H NMR spectra and 13000 13 C NMR spectra as well as FT-IR, Raman, ESR, and MS data. The data are stored and displayed as an image of the processed data. Annotation is achieved by a list of the chemical shifts correlated to letters which are also used to label a molecular line drawing.
Typically 2–50 mg of a substance is required to record a decent-quality NMR spectrum. The NMR method is non-destructive, thus the substance may be recovered. To obtain high-resolution NMR spectra, solid substances are usually dissolved to make liquid solutions, although solid-state NMR spectroscopy is also possible.
Figure 5 -Steps of SNIF-NMR of ethanol - Official method. The SNIF-NMR is applied on pure (or purified) molecules. Therefore, some preparation steps may be required in the lab before analysis. For example, for the SNIF-NMR of ethanol, according to official methods: Fermentation (for fruit juice) Quantitative extraction of ethanol by distillation
Simple molecules have simple spectra. The spectrum of ethyl chloride consists of a triplet at 1.5 ppm and a quartet at 3.5 ppm in a 3:2 ratio. The spectrum of benzene consists of a single peak at 7.2 ppm due to the diamagnetic ring current. Together with carbon-13 NMR, proton NMR is a powerful tool for molecular structure characterization.
An infrared spectroscopy correlation table (or table of infrared absorption frequencies) is a list of absorption peaks and frequencies, typically reported in wavenumber, for common types of molecular bonds and functional groups.