2,3-Dimethylbutane and 2,2-dimethylbutane have the same molecular ion in the mass spectrum, but only one of these isomers gives a significant fragment at m/z = 57. (a) Which isomer shows an intense peak at m/z = 57? (b) Propose a structure for the ion that gives rise to this peak. (c) The base peak in the mass spectrum of the other isomer occurs at m/z = 43. What ion gives rise to this peak?

2,3-Dimethylbutane and 2,2-dimethylbutane have the same molecular ion in the mass spectrum, but only one of these isomers gives a significant fragment at m/z = 57. (a) Which isomer shows an intense peak at m/z = 57? (b) Propose a structure for the ion that gives rise to this peak. (c) The base peak in the mass spectrum of the other isomer occurs at m/z = 43. What ion gives rise to this peak?

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter14: Mass Spectrometry

Section: Chapter Questions

Problem 14.29P

See similar textbooks

Similar questions

Write molecular formulas for compounds that show the following molecular ions in their high-resolution mass spectra, assuming that C, H, N, and O might be present. The exact atomic masses are: 1.007 83 (1H), 12.000 00 (12C), 14.003 07 (14N), 15.994 91 (16O). (a) M+=98.0844 (b) M+=123.0320
The mass spectrum (a) and the infrared spectrum (b) of an unknown hydrocarbon are shown. Propose as many structures as you can.
Butanal and methylpropanal give slightly different mass spectra. Both give a molecular ion peak at m/z = 72, but butanal gives four other peaks whereas methylpropanal only gives three. State the species responsible for the four other peaks in the mass spectrum of butanal and write equations to show their formation from the molecular ion.
Propylbenzene, C6H5CH2CH2CH3, and isopropyl benzene, C6H5CH(CH3)2, are constitutional isomers with the molecular formula C9H12. One of these compounds shows prominent peaks in its mass spectrum at m/z 120 and 105. The other shows prominent peaks at m/z 120 and 91. Which compound has which spectrum?
Is the structure on the bottom right corner of the FTIR photo correct for the mass spectrum, FTIR, and a proton NMR that has a doublet with an integration of 3 hydrogens at 7.25 ppm, a triplet with an integration of 1 hydrogen at 7.41 ppm, and a singlet with an integration of 6 hydrogen at 2.6 ppm? If not, what is the correct structure?
A compound has a molecular ion in its mass spectrum at m / z = 58, and a strong absorption band at its IR at 1720. What would be the structure?
analyse the spectra and write the name of the compound. Also write brief explanation for each spectra verifying the part of you suggested molecule (For IR indicate the functional groups which matches the peaks, for mass indicate the fragments, for CNMR and HNMR indicate which peak to what).(maximum character: 60000)
Propose a molecular formula for a compound that exhibits the following peaks in its mass spectrum. (M)+• at m/z = 68, relative height = 100% (base peak) (M+1)+• at m/z = 69, relative height = 4.3%
Mass spectra of butylcyclopentane and tert-butylcyclopentane were acquired. Spectrum A exhibited significant mass peaks at m/z values of 126, 97, 83, 69, 55, and 41. Spectrum B exhibited significant peaks at m/z values of 111, 69,57, and 41. Match each spectrum with its compound.
Which structure would show major fragment ion at 59 and 73 m/z in its mass spectrum?
Assign molecules A, E, G, and H to the correct mass spectrum and provide the structure of thebase peak.
The low-resolution mass spectrum of an unknown analgesic X had a molecular ion of 151. Possible molecular formulas include C7H5NO3, C8H9NO2, and C10H17N. Highresolution mass spectrometry gave an exact mass of 151.0640. What is the molecular formula of X?