Nmre ___________________________

1. (5 pts) Match the C-13 spectra below to the small alcohols:

______ CH₃CH₂ CH₂OH 1-propanol

______ (CH₃)₂CHOH iso propyl alcohol

______ (CH₃)₂CH CH₂OH iso butyl alcohol

Spectrum A all peaks equal size

Spectrum B right peak twice height of left

Spectrum C right peak twice height of others

2. (10 pts) Determine the structure of both of the following compounds. Indicate what peaks correspond to which carbons in the structure.

Molecular Formula	chemical shifts (dept results, intensity) u-up n- not there d-down three results from bottom to top on dept spectra.
a) C5H11Cl	22(unu,2) 26(uuu,1) 42(und,1) 43(und,1)
b) C4H8O2	161(uuu,1) 67(uuu,1) 22(unu,2)

3. (44 points-4 pts each) Short answers.

i) On a 60 MHz instrument, 0.2 ppm in the proton spectrum corresponds to _______ Hz. On the same instrument C-13 is run at a frequency of 15 MHz. On its spectrum, 0.2 ppm corresponds to __________ Hz.

ii) . ¹H has a spin of _____ and ____ orientations where as ²H has a spin of ____ and ____ orientations.

iii-vi. Consider the NMR of

2 methyl-2- butanol.

iii. Draw the structure of the compound.

iv) The proton spectrum will consist from high to low chemical shift:

a) a singlet, and a multiplet (splitting greater than 4), a singlet and a triplet

b) a quartet, and a doublet and a singlet

c) a doublet, a multiplet. and a doublet

d) a triplet, a singlet, and a doublet

e) a singlet, a quartet, a singlet, and a triplet

v. The integration of the peaks from high to low chemical shift will be:

a) 1:2:6:3 b) 1:1::9:2 c) 2:1:6 d) 4:3:2 e) 1:2:6

vi. The decoupled C-13 spectrum will consist from high to low chemical shift of:

a) 5 peaks of equal intensity.

b) 4 peaks with one of the middle peaks double the intensity of the other three.

c) 5 peaks with one of the middle peaks double the intensity of the other four.

d) none of these

vii. On the Unity plus 500 NMR in S-152, what is the H-1 frequency? (include your units)

viii. On the Unity plus 500 NMR in S-152, what is the C-13 frequency? (include your units)

ix. At what temperature is the electromagnet kept at? (include your units)

x. The signal to noise ratio on a certain instrument is 15:1 when run on a 5 % solution with 16 scans. On the same instrument how many scans will it take to get a signal to noise ratio of 45:1 on a 1 % solution of the same compound? Show your work.

xi. Consider the proton spectrum of an ethyl group. The methylene group, CH₂, has a total intensity of 20. What is the total intensity of the methyl group, CH₃, and what would be the intensity of each line in the spectrum?