CHEM 130 Lecture Notes - Lecture 5: Proton Nuclear Magnetic Resonance, Carbon-13 Nuclear Magnetic Resonance, Chemical Shift

• School: BRCC
• Department: CHEM - Chemistry
• Course: CHEM 130
• Professor: Larry Dalton

Document Summary

Integration tells us the number of hydrogen atoms in each peak. The chemical shift of the twelve hydrogen atoms of the four identical methyl groups in me4si is defined as zero. The methyl group in the acid is next to the carbonyl group and so slightly deshielded at about d 2. 0 p. p. m. and the acidic proton itself is very deshielded at d 11. 2 p. p. m. The same factor that makes this proton acidic the o h bond is polarized towards oxygen also makes it resonate at low field. So far things are much the same as in carbon nmr. Notice that the ratio of the peak heights in this spectrum was about 3:1 and that that is also the ratio of the number of protons. In fact, it"s not the peak height but the area under the peaks that is exactly proportional to the number of protons.