Question

Predict the approximate chemical shifts of the protons in the following compounds.

a)Benzene

b)Cyclohexane

c)

d)

e)

f)

g)

h)

i)

j)

k)

l)

Short answer

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppmof TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (a) molecule keeping in mind the factors affecting chemical shift.

Please mention that aromatic protons have chemical shift value around 7.1

The chemical shift values of protons

Step-by-step solution

Explanation of part (a):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppmof TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (a) molecule keeping in mind the factors affecting chemical shift.

Please mention that aromatic protons have chemical shift value around 7.1

The chemical shift values of protons

 Explanation of part (b):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (b) molecule keeping in mind the factors affecting chemical shift.

The chemical shift values of protons

Explanation of part (c):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift. The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (c) molecule keeping in mind the factors affecting chemical shift.

The chemical shift values of protons

 Step 4: Explanation of part (d):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (d) molecule keeping in mind the factors affecting chemical shift.

The chemical shift values of protons

Explanation of part (e):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (e) molecule keeping in mind the factors affecting chemical shift.

The chemical shift values of protons

Explanation of part (f):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (f) molecule keeping in mind the factors affecting chemical shift.

The chemical shift values of protons

Explanation of part (g):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow, as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decrease the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. The electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (g) molecule keeping in mind the factors affecting chemical shift.

Chemical shift values of protons

 Explanation of part (h):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (h) molecule keeping in mind the factors affecting chemical shift.

Chemical shift values of protons

 Explanation of part (i):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (i) molecule keeping in mind the factors affecting chemical shift.

Chemical shift values of protons

 Explanation of part (j):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (j) molecule keeping in mind the factors affecting chemical shift.

Chemical shift values of protons

Explanation of part (k):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decreases the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. Electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (k) molecule keeping in mind the factors affecting chemical shift.

The chemical shift values of protons

Explanation of part (l):

The NMR spectra is displayed as a plot of the applied radio frequency versus the absorption. The position on the plot at which the nuclei absorb is called the chemical shift.The range at which most NMR absorptions occur is narrow, as almost all absorptions occur downfield within 10 ppm of TMS. Electron-withdrawing groups decrease the electron density at the nucleus, deshielding the nucleus and result in larger chemical shift. The electronegativity of the atom also increases the chemical shift of attached proton.

The chemical shift values have been assigned in part (l) molecule keeping in mind the factors affecting chemical shift.

The chemical shift values of protons