15. Analytical Techniques:IR, NMR, Mass Spect

A ¹H NMR spectrum has a singlet at 4.1 ppm with an integration of 2H. How many hydrogen atoms are on the neighboring carbon atom?

A ¹H NMR spectrum contains a quartet at 4.1 ppm integrating to 2H and triplet at 0.9 ppm integrating to 3H, among other signals. What fragment is likely part of this molecule?

Which of the following structures would give the following ¹H NMR spectrum? 0.93 ppm (s, 9H), 2.13 ppm (d, 2H), 9.85 ppm (t, 1H)

Draw the expected NMR spectrum of methyl propionate, and point out how it differs from the spectrum of ethyl acetate.

Each of these four structures has molecular formula C4H8O2. Match the structure with its characteristic proton NMR signals. (Not all of the signals are listed in each case.)

(a) sharp 1H singlet at d 8.0 and 2H triplet at d 4.0 (b) sharp 3H singlet at d 2.0 and 2H quartet at d 4.1 (c) sharp 3H singlet at d 3.7 and 2H quartet at d 2.3 (d) broad 1H singlet at d 11.5 and 2H triplet at d 2.3