The following exercises are designed to help you become familiar with predicting the 1H NMR spectra of simple organic molecules. For each example you should find the number of signals you expect, where they should show on the scale (chemical shift), and what shape they should be (splitting patterns).
NMR Practice Problem (Part II) Winter 2016 (Problems from former Chem 30BL finals)
Chapter 13: NMR Spectroscopy Problem Set 1) For each compound below, identify each chemically distinct type of hydrogen. Specify the number of 1H NMR signals you would expect to see. 2) Which of the indicated protons in each pair shows up farther downfield? Tips: For H-C-Z, H moves further downfield as Z becomes more electronegative
W has an empirical formula of C10H13NO2. Given are the following spectra. Determine the degree of unsaturation for the compound. Assign five pertinent peaks in the infrared spectrum. Suggest a structure for compound W based on the spectra given. Show all your work and clearly indicate what your final answer is. 2 3. DEPT 135. DEPT 90.
Some good resources to practice NMR problems and combined spectral problems (ones that have proton, carbon, and sometimes IR and MS data) are listed below. The first site has tons of practice problems at all levels, from beginning to advanced.
Proton NMR and combined practice problems Page 4 4. Propose a structure that is consistent with the data provided (IR, Mass Spec, 1H NMR, 13C NMR, and molecular formula).
Proton NMR The Proton NMR contains three peaks which indicates the existence of three unique hydrogen environments where each are split according to the arrangement of adjacent hydrogen nuclei. Using the carbon-13 NMR and IR peaks it can be observed the presence of a CH 3, CH 2 and OH groups which create the hydrogen environments in propanoic acid.
Chem 360 Jasperse NMR Practice Problems 25 25. Carbon NMR: 2D Carbon-Hydrogen (HSQC) and 2D Hydrogen-Hydrogen (COSY) spectra. C 7H 14O Fri Feb 4 23:54:49 2011: Experiment started Fri Feb 4 23:53:02 2011: Experiment started Fri Feb 4 23:53:33 2011: Acquisition complete 14.17 21.04 14.40
NMR Practice Problems 1) Tell precisely how you would use the proton NMR spectra to distinguish between the following pairs of compounds: a. 1-bromopropane and 2-bromopropane b. propanal and propanone c. ethyl acetate (MeCO2Et) and methyl propanoate (EtCO2Me) d. 1-butyne and 2-butyne 2) Each of the following compounds exhibits a single 1H NMR peak.
1H and 13C NMR Spectroscopy Questions Deduce which of the two esters produced the spectrum shown. In your answer, explain the position and splitting of the quartet peak at δ = 4.1 ppm in the spectrum. Predict the δ value of the quartet peak in the spectrum of the other ester. Use Table B on the Data Sheet.
Below are good additional resources to practice NMR problems – many of them have “combined” spectral problems (ones that have proton, carbon, IR and MS data). Try this site for tons of practice problems at all levels, from beginning to advanced.
Identify each 13C-NMR signal as either alkyl, vinyl, alkynyl, aryl, nitrile, imine, or carbonyl (you do not need to assign individual carbon atoms to each signal). Assign each key IR absorption band >1500 cm -1 to a specific functional group.
advanced structure elucidation course, it became clear that beginning students needed an easily accessible set of 2D NMR spectral problems with answers for practice. Thus, a database of 2D NMR problems with answers was developed to help …
Practice problems on the NMR of amino acids Test your ability to correlate NMR spectra with structure by trying the following problems. Use the correlation tables, the relative sizes of the signal, electronegativity and the number of signals and …
- identify each 13C-NMR signal as either alkyl, vinyl, alkynyl, aryl, nitrile, imine, or carbonyl (you do not need to assign individual carbon atoms to each signal). - identify each IR absorption band as due to a specific functional group.
Title: NMR Practice Problems (Solutions) Author: Dr. Laurie S. Starkey Created Date: 4/10/2014 10:24:48 PM
W has an empirical formula of C10H13NO2. Given are the following spectra. Determine the degree of unsaturation for the compound. Assign five pertinent peaks in the IR spectrum. Suggest a structure for compound W based on the spectra given. Show all your work and clearly indicate what your final answer is. t s. 2 3 “m” t. DEPT 135. DEPT 90.
Chapter 13: NMR Spectroscopy Problem Set 1) For each compound below, identify each chemically distinct type of hydrogen. Specify the number of 1H NMR signals you would expect to see. 2) Which of the indicated protons in each pair shows up farther downfield? Tips: For H-C-Z, H moves further downfield as Z becomes more electronegative 3For C
The IR and 1H NMR spectra of a compound of molecular formula C10H12O are given below. Calculate the degree of unsaturation. b. List the possible functional groups gleaned from the molecular formula. c. What is the oxygen-containing functional group that the IR spectrum shows to be present in the unknown? d. Propose a structure for this compound. 2.
W has an empirical formula of C10H13NO2. Given are the following spectra. Determine the degree of unsaturation for the compound. Assign five pertinent peaks in the infrared spectrum. Suggest a structure for compound W based on the spectra given. Show all your work and clearly indicate what your final answer is. 2 3. DEPT 135. DEPT 90.
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