CHEM 211 Lecture Notes - Lecture 20: Benzene, Chemical Shift, Topicity
27 Oct 2016
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Benzene ring: four degrees of unsaturation, two types of hydrogens. Singlets: can be split into a doublet if the groups next to it are different. Though you can"t be split into something that"s the same as the group. Integration of single areas: the area under each single is proportional to the hs. Nuclear spin: magnetic eld vs no magnetic eld. With the magnet, either aligns against or with the magnet: labeled beta and alpha, alpha has a little more energy compared to beta. Spin quantum number: you can only see nmr for atoms with a spin of 1/2. Must be odd numbers. cant see even numbers (ex. carbon 12) Ppm and the scale: the chemical shift is expressed in hertz (hz) is proportional to the strength of the external magnetic eld. Exchangeable proton = anything that can be basic or acidic: when you shake them in d2o, the peaks disappear. Most of the time it"s probably and oh.
