Label each set of chemically equivalent protons, using a for the set that will be at the

How many signals are produced by each of the following compounds in its a. 1 H NMR spectrum? b. 13 C NMR spectrum? 1. CH3 OCHCH3 CH3 2. C O OCH2CH3 3. O O 4. O 5. Cl 6.

Draw a splitting diagram for the H b proton and give its multiplicity if a. Jba = Jbc b. Jba = 2Jbc Ha C CCX Ha Ha Hb Hc X X

Label each set of chemically equivalent protons, using a for the set that will be at the lowest frequency (farthest upfi eld) in the 1 H NMR spectrum, b for the next lowest, and so on. Indicate the multiplicity of each signal.

Match each of the 1 H NMR spectra with one of the following compounds: CH3CNO2 CH3 CH3 CH CH3CHBr 3CH2CH2NO2 CH3CH2NO2 CH3 CH3CH2 CH3 C O CH3CH2 CH2CH3

Determine the ratios of the chemically nonequivalent protons in a compound if the steps of the integration curves measure 40.5, 27, 13, and 118 mm, from left to right across the spectrum. Draw the structure of a compound whose 1 H NMR spectrum would show these integrals in the observed order.

How could 1 H NMR distinguish between the compounds in each of the following pairs? O O a. and b. Br NO Br and Br 2 c. CH3CH CHCH3 and CH3 CH3 CH3CCH2CH3 CH3 CH3 d. O CH3 C C OCH3 and CH3 CH3 CH3 C CH3 OCH3 OCH3 e. CH3O OCH CH2CH3 and CH3 2CH3 f. and g. CH3CHCl and CH3 CH3CDCl CH3 h. Cl Cl H CH3 and D H Cl Cl D CH3 H H i. and H Cl Cl H H Cl H Cl j. CH3 CCH3 and CH3 CH3 CH2CCH3 CH3 CH3

Answer the following questions: a. What is the relationship between chemical shift in ppm and operating frequency? b. What is the relationship between chemical shift in hertz and operating frequency? c. What is the relationship between coupling constant in hertz and operating frequency? d. How does the operating frequency in NMR spectroscopy compare with the operating frequency in IR and UV/Vis spectroscopy?

The 1 H NMR spectra of three isomers with molecular formula C 4 H 9 Br are shown here. Which isomer produces which spectrum?

How many signals are produced by each of the following compounds in its a. 1 H NMR spectrum? b. 13 C NMR spectrum? H3C CH3 H3C CH3 H3C H3C CH3 CH3 3. 4. 6. CH3 1. 2. 5

Identify each of the following compounds from the 1 H NMR data and molecular formula. The number of hydrogens responsible for each signal is shown in parentheses. a. C 4 H 8 Br 2 1.97 ppm (6) singlet 3.89 ppm (2) singlet b. C 8 H 9 Br 2.01 ppm (3) doublet 5.14 ppm (1) quartet 7.35 ppm (5) broad singlet c. C 5 H 10 O 2 1.15 ppm (3) triplet 1.25 ppm (3) triplet 2.33 ppm (2) quartet 4.13 ppm (2) quartet

Identify the compound with molecular formula C 7 H 14 O that gives the following proton-coupled 13 C NMR spectrum:

Compound A, with molecular formula C 4 H 9 Cl, shows two signals in its 13 C NMR spectrum. Compound B, an isomer of compound A, shows four signals, and in the proton-coupled mode, the signal farthest downfi eld is a doublet. Identify compounds A and B.

The 1 H NMR spectra of three isomers with molecular formula C 7 H 14 O are shown here. Which isomer produces which spectrum?

Would it be better to use 1 H NMR or 13 C NMR spectroscopy to distinguish among 1-butene, cis -2-butene, and 2-methylpropene? Explain your answer.

There are four esters with molecular formula C 4 H 8 O 2 . How can they be distinguished by 1 H NMR?

An alkyl halide reacts with an alkoxide ion to form a compound whose 1 H NMR spectrum is shown here. Identify the alkyl halide and the alkoxide ion. ( Hint: See Section 10.10 .)

Determine the structure of each of the following unknown compounds based on its molecular formula and its IR and 1 H NMR spectra. 3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 Wavenumber (cm1) a. C5H12O % Transmittance 4000 8765 3 2 3 2 2 3 4 210 d (ppm) frequency 1 3 C6H12O2 C4H7ClO2 c. C4H8O2 d.

Determine the structure of each of the following compounds based on its molecular formula and its 13 C NMR spectrum: b. C6H12O

The 1 H NMR spectrum of 2-propen-1-ol is shown here. Indicate the protons in the molecule that give rise to each of the signals in the spectrum.

How can the signals in the 6.5 to 8.1 ppm region of their 1 H NMR spectra distinguish the following compounds? OCH3 OCH3 OCH3 NO2 NO2 NO2

The 1 H NMR spectra of two compounds, each with molecular formula C 11 H 16 , are shown here. Identify the compounds.

Draw a splitting diagram for the H b proton if Jbc = 10 and Jba = 5 . a c b Cl H CH2Cl H C C

Sketch the following spectra that would be obtained for 2-chloroethanol: a. The 1 H NMR spectrum for an anhydrous sample of the alcohol. b. The 1 H NMR spectrum for a sample of the alcohol that contains a trace amount of acid. c. The 13 C NMR spectrum. d. The proton-coupled 13 C NMR spectrum. e. The four parts of a DEPT 13 C NMR spectrum.

How can 1 H NMR be used to prove that the addition of HBr to propene follows the rule that says that the electrophile adds to the sp2 carbon bonded to the greater number of hydrogens?

Identify each of the following compounds from its molecular formula and its 1 H NMR spectrum: 5 1 1 1 1 3 C8H8 b. C6H12O c. C9H18O d. C4H8O

Dr. N. M. Arr was called in to help analyze the 1 H NMR spectrum of a mixture of compounds known to contain only C, H, and Br. The mixture showed two singletsone at 1.8 ppm and the other at 2.7 ppmwith relative integrals of 1 : 6, respectively. Dr. Arr determined that the spectrum was that of a mixture of bromomethane and 2-bromo-2-methylpropane. What was the ratio of bromomethane to 2-bromo-2-methylpropane in the mixture?

Calculate the amount of energy (in calories) required to fl ip an 1 H nucleus in an NMR spectrometer that operates at 300 MHz.

The following 1 H NMR spectra are for four compounds, each with molecular formula of C 6 H 12 O 2 . Identify the compounds.

When compound A (C 5 H 12 O) is treated with HBr, it forms compound B (C 5 H 11 Br). The 1 H NMR spectrum of compound A has one singlet (1), two doublets (3, 6), and two multiplets (both 1). (The relative areas of the signals are indicated in parentheses.) The 1 H NMR spectrum of compound B has a singlet (6), a triplet (3), and a quartet (2). Identify compounds A and B.

Determine the structure of each of the following compounds, based on its molecular formula and its IR and 1 H NMR spectra: 3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 Wavenumber (cm1 ) C6H12O % Transmittance 4000 a. 3 2 1 8765 3210 4 d (ppm) frequency 3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 Wavenumber (cm1 ) % Transmittance 4000 b. C6H14O c. 10 9 876 4 3 2 2 2 2 1 2 2 5 210 d (ppm) frequency 4600 4400 4200 4000 3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 Wavenumber (cm1 ) NEAT % Transmittance C11H14O2

Determine the structure of each of the following compounds, based on the compounds mass spectrum, IR spectrum, and 1 H NMR spectrum:

Identify the compound with molecular formula C 6 H 10 O that is responsible for the following DEPT 13 C NMR spectrum:

Identify the compound with molecular formula C 6 H 14 that is responsible for the following 1 H NMR spectrum