University 01 Cincinnati Cincinnati. 45221
Phosphorus Coupling in 13C and l H NMR
rameters, or they can begiven the parametersand asked todraw the spectrum. In either case, the student comes to appreciate that the "extra" effects of a phosphorus atom can be dealt with, using the same (n 1) methodology used for protons. Four examples are shown below.2 Another question that can he pertinently raised is why CDCb shows a three-line carbon resonance. The reason is that deuterium has a nuclear spin o f I = 1,any resonance which is coupled to a single D will be split into 2 1 1 = 3 lines of equal intensity.
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George A. Krudy and Roger S. Macomber Uniuersity of Cincinnati Cincinnati, Ohio 45221
Although 1H nmr spectroscopy has become a staple in every undergraduate chemistry major's diet, the effects of hetermtoms with nonzero nuclear spin are rarely given the attention they deserve. Discussion of the effects of e.g. I9For "P serve not only to expand the students ability to solve a wider variety of spectral problems, hut also to cement their concepts of "first order" nuclear coupling. Our group has prepared a variety of organophosphorus compounds which exhibit extremely informative 'Hand '"C spectra.' Students can he given the spectrum and asked to measure the spectral pa-
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1 Macomber, R. S., J. 0 r g Chem., 43,1832 (1978). Macomber, R. S., and Kennedy, E. R., J. Org. Chem., 41,3191 (1976). Macomber, R. S., and Krudy, G. A,, J. Org. Chem., 43,4656 (1978). Reoroductions of the four s ~ e c t r awill be sent upon request to R.
ppm downfield born TMS
Volume 56, Number 2 February 1979 / 109
