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=The Spectral Game=
 * Developed by Jean-Claude Bradley, Robert Lancashire, Andrew Lang and Antony Williams**

Links
[|Play the game!] [|Latest and High Scores] [|Contribute spectra] to [|ChemSpider] as Open Data. [|UsefulChem 3/1/09 post]

Spectroscopy Resources
[|Organic Structure Determination (Open Courseware)] [|WebSpectra] [|Spectroscopy Page] (Organic Chemistry Wikibook) [|Dhavale NMR presentation]

Nuclear Magnetic Resonance Spectroscopy (NMR)

 * [|Reusch]
 * can view every H and C in molecules as peaks
 * scale in ppm (delta scale), relative to tetramethylsilane (TMS), defined as zero
 * in a typical NMR plot, higher ppm are on the left (low field, more deshielded)
 * integration corresponds to number of Hs
 * electronegative elements deshield
 * adjacent and non-equivalent (2-3 bonds) H's couple with each other and split peaks (N+1 rule), giving coupling constant J
 * J for alkenes: cis 10 Hz, trans 15 Hz, geminal 2 Hz
 * J for aromatics: ortho 8 Hz, meta 2 Hz
 * CH2 next to chiral center are diastereotopic and the H's are not equivalent
 * alkanes 0.9-1.5 ppm
 * aromatics 7-8 ppm
 * alkenes 5-6 ppm
 * aldehydes 9-10 ppm
 * terminal alkyne H 2.5 ppm
 * benzylic or next to ketone or aldehyde 2.1 - 2.3 ppm
 * CH2-X (X = O,N,halogen) 3 - 4 ppm
 * carboxylic acid 10-12 ppm, although may be very broad
 * amine and alcohols may be broad, very variable and not undergo 3 bond coupling
 * in ultrapure samples, H of OH may exhibit 3 bond coupling and splitting
 * hydrogen bonding H's can be replaced with H NMR invisible D's by adding D2O or CD3OD
 * C NMR do not show C-C coupling because only about 1% of C's are C-13
 * C NMR are usually proton spin decoupled so that only singlets are obtained
 * C NMR shifts: carbonyl 160-210 ppm, aromatic 100-150 ppm, alkynes 75-95 ppm, alkanes 0-35 ppm

Problems

 * [|Reusch All NMR (scroll down)]
 * [|UCalgary All Spectroscopy]

Infrared Spectroscopy (IR)

 * [|Reusch]
 * measures the bending and stretching of bonds
 * higher wavenumber (in cm^-1) corresponds to higher energy
 * heavier atom gives lower energy and lower wavenumbers
 * higher bond energies (e.g. single -> double -> triple bonds) give higher wavenumbers
 * useful range 1600-3500 cm^-1 (any absorptions below that are in the fingerprint region)
 * C=C unconjugated alkene 1640-1680
 * C=C conjugated alkene 1620-1640
 * C=C aromatic 1600
 * C-H (sp3) 2900-3000
 * C-H (sp2) 3000-3100
 * C-H (sp) 3300
 * hydrogen bonded N-H, O-H broad near 3300, CO2H very broad 2500-3500
 * C=O ketone, aldehydes, carboxylic acids 1710
 * C=O conjugated ketone or aldehyde 1680
 * C=O esters 1730-1740
 * C=O amides 1640-1680
 * C-H aldehyde 2700 and 2800
 * C=N 1660
 * CN (nitrile) 2250
 * CC alkyne 2150