The mass of spectrum of 2,4-dimethylpentane shows peaks at m/z 43, 57, and 85. Show the fragments which produce these peaks.
Ima =3
To determine the fragments that produce the peaks in the mass spectrum of 2,4-dimethylpentane, we need to consider the possible fragmentations of the molecule.
First, let's determine the molecular formula of 2,4-dimethylpentane:
C7H16
Now, let's analyze the peaks at m/z 43, 57, and 85:
1. Peak at m/z 43:
The most common fragment that produces an m/z of 43 in an organic compound is CH3+. This fragment represents one methyl group (CH3) that has lost an electron.
2. Peak at m/z 57:
The most common fragment that produces an m/z of 57 in an organic compound is C3H9+. This fragment represents an isopropyl (CH3-CH(CH3)-) group that has lost an electron.
3. Peak at m/z 85:
The most common fragment that produces an m/z of 85 in an organic compound is C5H11+. This fragment represents a pentyl (CH3-CH2-CH2-CH2-CH2-) group that has lost an electron.
Therefore, the fragments that produce the peaks in the mass spectrum of 2,4-dimethylpentane are:
- m/z 43: CH3+
- m/z 57: C3H9+
- m/z 85: C5H11+
To determine the fragments that produce the peaks in the mass spectrum of 2,4-dimethylpentane, we need to consider the possible fragmentation patterns and the resulting fragment ions.
1. Peak at m/z 43:
This peak suggests the presence of a small fragment. Common fragments at m/z 43 are methyl cations (CH3+). Since 2,4-dimethylpentane has two methyl groups, it is likely that the m/z 43 peak represents the fragment CH3+.
2. Peak at m/z 57:
This peak corresponds to a larger fragment. Some possible fragments at m/z 57 include propyl cations (C3H7+) or an ethyl cation (C2H5+). However, since 2,4-dimethylpentane has no propyl groups, it is more likely that the m/z 57 peak represents the ethyl cation (C2H5+).
3. Peak at m/z 85:
This peak suggests the presence of a larger fragment. One possible fragment at m/z 85 is the 2,4-dimethylbutyl cation (C7H15+), which can be formed by the loss of a methyl group and an ethyl group. Therefore, it is likely that the m/z 85 peak represents the fragment C7H15+.
In summary, the peaks at m/z 43, 57, and 85 in the mass spectrum of 2,4-dimethylpentane most likely correspond to the fragments CH3+, C2H5+, and C7H15+, respectively.