There are six isomers of C4H8. — Analytical Chemistry — Spectroscopy Chemistry Question
Nuclear magnetic resonance (NMR) spectra of isomers of C4H8
There are six isomers of C4H8.
Draw the structural formulas of all the isomers.
Model Answer
[VISUAL]
One of the isomers has only one singlet peak in its proton NMR spectrum. Name this isomer.
Model Answer
All the protons in this isomer are magnetically equivalent. Thus, the answer is cyclobutane.
One of the isomers has two singlet peaks in its proton NMR spectrum. Name this isomer. Also estimate the area ratio of the two peaks.
Model Answer
This isomer has only two magnetically non-equivalent protons without spin-spin coupling. Thus, the answer is methylpropene (or isobutene, isobutylene). The numbers of two non-equivalent protons in methylpropene are two and six. Thus, the intensity ratio = 6/2 = 3 (or 2/6 = 1/3).