CHEM 2OA3 Lecture 4: Podcast 4 Carbon NMR
7 Feb 2017
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Document Summary
Nmr is far more information rich than infrared or mass spec. Proton: several different pieces of independent information: chemical shift tells about environment of protons, technique is quantitative: how many methyls in a particular site (3=methyl), gives environmental structural information. Protons recognize the presence of their neighbours: connectivity information. Measuring signal of connectivity gives information about geometry of the molecule (ex: cis or trans): recording and using c-13 nmr spectra, theory: the nmr phenomenon, using proton nmr spectra, theory: coupling, special features of nmr spectra. Carbon nmr allows us to look at each c atom in a compound and know its local environment. Gives the number of c and their local environment. Proton nmr does the same thing, but with hydrogens. Units: ppm - runs from 0-220 ppm. Different c nuclei absorb different energies, which are shown on the x-axis. Delta-0 is the energy or frequency at which c atoms of tms undergo nmr phenomenon.
