(a)
Interpretation:
The bond at which fragmentation occurs in the structure of
Concept introduction:
Mass spectroscopy is used to calculate mass to charge ratio of ions. Isotopic peak is also known as
(b)
Interpretation:
The mechanism for the fragmentation of the bond between two methylene group is to be stated.
Concept introduction:
Mass spectroscopy is used to calculate mass to charge ratio of ions. Isotopic peak is also known as
(c)
Interpretation:
The structure of the fragment ion of
Concept introduction:
Mass spectroscopy is used to calculate mass to charge ratio of ions. Isotopic peak is also known as
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Organic Chemistry
- 36 5 s > Q2/ A) ethyl propyl ether (M=88) that has the following absorption peaks in mass spectrum (m/z= 73, 59, 43,31,29) suggest fragment mechanism for this compound :arrow_forwardWhen benzophenone is illuminated with ultraviolet radiation it is excited into a singlet state. Th is singlet changes rapidly into a triplet, which phosphoresces. Triethylamine acts as a quencher for the triplet. In an experi ment in methanol as solvent, the phosphorescence intensity varied with amine concentration as shown below. A timeresolved laser spectroscopy experiment had also shown that the half-life of the fluorescence in the absence of quencher is 29μs. What is the value of the quenching rate constant kO ?arrow_forwardThe weight of proteins or nucleic acids in solution is often determined by UV spectroscopy using the Beer-Lambert law. For example, the molar absorptivity, ɛ, of double-stranded DNA at 260 nm is 6670 M'cm-!. The formula weight of the repeating unit in DNA (650 Daltons) can be used as the molecular weight. What is the weight of DNA in 4.0 mL of aqueous buffer if the absorbance, measured in a 1-cm cuvette, is 0.35? Choose the correct value from the drop-down list provided. Weight of DNA: gramarrow_forward
- 8 Give logical fragmentation reactions to account for the following ions observed in these mass spectra.(a) n-octane: 114, 85, 71, 57 (b) methylcyclohexane: 98, 83 (c) 2-methylpent-2-ene: 84, 69(d) pentan-1-ol: 70, 55, 41, 31arrow_forwardThe mass spectrum of compound B is shown below. 100 180 80 181 77 В 182 20 104 25 50 75 100 125 150 175 200 m/z (i) Identify the molecular ion peak of compound B. (ii) Explain the peak at m/z 182 in terms of intensity. (iii) Explain the formation of the other labelled fragments (m/z 180, 104 and 77). Relative Intensityarrow_forward+4 36 5 7 21 thyl propyl ether (M=88) that has the following absorption peaks in mass spectrum (m/z73, 59, 43,31,29) suggest fragment mechanism for this compound :arrow_forward
- Suggest identities for the following neutral molecules commonly lost in mass spectral fragmentation: (a) mass = 28 - lost from a compound containing only C and H (b) mass = 18 - lost from a compound containing C, H, and O (c) mass = 36 - lost from a compound with an M+2 peak about one-third the size of the molecular ionarrow_forward[References] The mass spectrum of octanoic acid, CH3(CH2)6COOH, exhibits a series of peaks differing by 14 amu at m/z 29, 43, 57, 71, 85, and 99. Draw the structure of the fragment resulting in the m/z 71 peak. • You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms. • In cases where there is more than one answer, just draw one. • Do not use the square brackets tool in your answer. opy aste H,C earch 84%arrow_forwardPredict the masses and the structures of the most abundant fragments observed in the mass spectra of the followingcompounds.(a) 2-methylpentane (b) 3-methylhex-2-ene (c) 4-methylpentan-2-ol(d) 2-methyl-1-phenylpropanearrow_forward
- 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.arrow_forwardThe functional groups in an organic compound can frequently be deduced from its infrared absorption spectrum. A compound containing no nitrogen exhibits strong, broad absorption across the 2500-3300 cm-1 region, accompanied by 2200 (w) and 1715 (s) cm-1bands.Relative absorption intensity: (s)=strong, (m)=medium, (w)=weak. What functional class(es) does the compound belong to? List only classes for which evidence is given here. Attach no significance to evidence not cited explicitly.Do not over-interpret exact absorption band positions. None of your inferences should depend on small differences like 10 to 20 cm-1. The functional class(es) of this compound is(are)fill in the blank 1.(Enter letters from the table below, in any order, with no spaces or commas.) a. alkane (List only if no other functional class applies.) b. alkene h. amine c. terminal alkyne i. aldehyde or ketone d. internal alkyne j. carboxylic acid e. arene k. ester f. alcohol l. nitrile g. etherarrow_forwardGive logical fragmentation reactions to account for the following ions observed in these mass spectra.(a) n-octane: 114, 85, 71, 57 (b) methylcyclohexane: 98, 83 (c) 2-methylpent-2-ene: 84, 69(d) pentan-1-ol: 70, 55, 41, 31 (e) N-ethylaniline (PhNHCH2CH3): 121, 106, 77*(f) 1-bromo-2-methylbutane: 152, 150, 123, 121, 71 (base)arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning