Lab A. 1H and 13C NMR Review Worksheet

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University of California, Berkeley *

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3BL

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Chemistry

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Feb 20, 2024

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Page 1 of 8 If turning in past original due date, provide explanation here: _________________________ CHEM 3BL Lab A: 1 H and 13 C NMR Review Worksheet Adapted From Dr. Alexis Shusterman and Dr. Pete Marsden Even though there are no questions on this page, include this page and all other pages in your submission to Gradescope. If you do not include all eight pages in the correct order, your answers will not show up in the correct locations when we are grading your work.

Page 2 of 8 1. The following ten structures each correspond to one of the 1 H NMR spectra on the next three pages. The integral values for each peak are next to that peak. Indicate which structure matches each spectrum by drawing the structures in the boxes along the right side of the page, then label the hydrogens with the corresponding letter codes indicated on the spectrum . When “umbrellas” appear, multiple answers are reasonable, but equivalent Hs still need to be labeled with the same letters and inequivalent Hs need to be labeled with different letters (see example). Ignore diastereotopic protons for this question.

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Page 5 of 8 2. The following 1 H NMR spectrum corresponds to a compound with the molecular formula C 8 H 8 O 2 . Draw the compound in the box next to the spectrum and then label the hydrogens with the corresponding letter codes indicated on the spectrum. 3. A. Circle the molecule below whose 1 H NMR spectrum would contain two doublets with integrals of 2H in the 6-8 ppm range. B. Circle the molecule below whose 1 H NMR spectrum would contain one singlet with an integral of 6H. C. Circle the molecule below whose 1 H NMR spectrum would contain two doublets in the 4-6 ppm range. D. Circle the molecule below whose 1 H NMR spectrum would contain two singlets with integrals of 3H.

Page 6 of 8 E. Match your answers from Question 3 parts A-D to the 1 H NMR spectra below. Indicate which structure matches each spectrum by drawing the structures in the boxes along the right side of the page, then label the hydrogens with the corresponding letter codes indicated on the spectrum . When “umbrellas” appear, multiple answers are reasonable, but equivalent Hs still need to be labeled with the same letters and inequivalent Hs need to be labeled with different letters.

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Page 7 of 8 4. Label the PROTONS on the structures on this page, using letters to designate the chemically equivalent ones. For this question, remember that some protons will likely be diastereotopic. Use a letter and the same letter with a prime ( ’ ) to denote protons that are diastereotopic when labeling the structures. Then, fill in the prediction table for each molecule with information pertaining to the integral (e.g. 1H, 3H, etc.), multiplicity (e.g. s, d, dt, ddd, etc.), and approximate chemical shift (e.g. 0-2 ppm, ~4 ppm, etc.). Remember that you can get complex splitting when there are different types of neighbors. There may be more rows than you will need. NOTE: Diastereotopic protons on the same carbon are considered "neighbors."

Page 8 of 8 5. A. Label the CARBONS on the structures below using letters to show which ones are chemically equivalent and which ones are different from each other. B. Label the CARBONS on the structures below , using letters to show which ones are chemically equivalent and which ones are different from each other. Then, fill in the tables with the requested information; you may have more rows than you need. One row has been completed for you as an example. Carbon Label Chemical Shift Carbon Label Chemical Shift A 0-50 ppm