Chapter 12C, Problem 82P

Shown below is the ¹H-NMR spectrum of a compound with the formula C5H10O2. 2H Peak Splitting quartet quartet triplet triplet 1 2 3 4 a b c d e a b CH3CH₂CH₂CH₂COH 2 A 2H PPM Choose from the constitutional isomers below to assign a structure to this spectrum. O B d CH3CH₂CH₂COCH3 3 3H 4 3H a b || c CH3CH₂COCH₂CH3 C (Choose the letter corresponding to the correct structure from the drop-down list provided.) Correct Structure: C Assign signal number 3 (indicated as a red number on the spectrum above) to its corresponding hydrogen(s) (shown as a red lower-case letter on the structure above). (Write the letter of the hydrogen (or set of equivalent hydrogens) in the box provided, e.g., a) Signal number 3 corresponds to hydrogen(s): Previous Next

(a) Draw all six isomers of formula C4H8 (including stereoisomers).(b) For each structure, show how many types of H would appear in the proton NMR spectrum.(c) For each structure, show how many types of C would appear in the 13C NMR spectrum.(d) If an unknown compound of formula C4H8 shows two types of H and three types of C, can you determine its structurefrom this information?

How many different 13C-absorption lines and how many 'H- resonances (disregard splitting and assume that solvent exchange of acidic hydrogens does NOT take place) are observed in the spectrum of each of the following compounds? (H3C)3C-C(CH3)2 CI A H3C (H3C)3C B CH3 CH3 H₂C= -COOH C CH-CI H3C-C-CH Cl Br D

(a) Draw all six isomers of formula C4H8 (including stereoisomers).(b) For each structure, show how many types of H would appear in the proton NMR spectrum.(c) For each structure, show how many types of C would appear in the 13C NMR spectrum.

A'2 The 'H-NMR spectra of cyclohexanol and cyclohexanone are given below. Identify which spectrum belongs to which compound and assign the peaks in each spectrum that substantiate your decision.

Why do aldehydes, esters, and amides all have a strong absorption in the 1630-1780 cm1 region of their IR spectra? A) The bond between H and the sp³-hybridized C in these functional groups vibrates in this energy range. B) Each of these functional groups has at least two resonance structures, and the different vibrations of the resonance structures give off energy in this region. C) The bond between O and the sp²-hybridized C in these functional groups vibrates at a frequency in this energy range. D) Light at this wavenumber causes the average C to O bond length to increase which causes more of this light to be transmitted. E) An electron in the bond of these functional groups gets excited to the * orbital.

(b) Determine the structure of an organic compound with a molecular ion at m/z 73 and absorption in its IR at 3300 (doublet) and 1680 cm

Compound 1 has molecular formula C6H12. It shows three signals in the 1H-NMR spectrum, one at 0.96 ppm, one at 2.03 ppm, and one at 5.33 ppm. The relative integrals of these three signals are 3, 2, and 1, respectively. Compound 2 has molecular formula C7H15Br. It shows two signals in the 1H-NMR spectrum, one at 1.08 ppm and one at 1.59 ppm. The relative integrals of these two signals are 3 and 2, respectively. Propose structures for compounds 1 and 2, explaining how you reach your conclusion.

Shown below is th carbon NMR spectrum of a compound of the formula C7H14. The compound decolorizes a solution of bromine in dichloromethane. Assign a structure to this hydrocarbon. Correlation of spectrum with number of hydrogen atoms attached to each carbon=