CHEM 214 Lecture Notes - Lecture 20: Larmor Precession, Zeeman Effect, Chloroform
26 Jun 2016
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Lecture 20: nmr spectroscopy v samedi 27 f vrier 2016. Involves energetic interactions of two adjacent nuclei (spin), and involves the electrons in the bond. A single spin 1/2 particle has two spin states (two possible energy states): alpha (lower in energy) and beta (magnetic moment is anti-parallel, higher in energy) A pair of spin 1/2 particles therefore has four spin states: aa, ab, ba, bb (proton spin state, carbon spin state) The frequencies of signals we detect in nmr experiments are proportional to the differences between energy levels. Single spin in the nmr, alpha state was lower in energy and beta was higher in energy, and the frequency of this peak was given by de/h. We can do the same interpretation when we consider the c and h signals of c13 chloroform. In the absence of any scalar coupling, we observe only two frequencies: (1) aa.
