Question

Question:Propose four possible structures for a hydrocarbon with a molecular ion at m/z= 112.

Short answer

Answer

Molecular formula, C₈H₁₆ (one degree of unsaturation—one ring or one pi bond).

Four structures with m/z= 112

Step-by-step solution

Base peak

The base peak indicates m/z value in mass spectra, and is the most intensive peak.The molecular peak is the highest peak in mass spectra, indicating the greatest relative abundance.

Degree of unsaturation

The degree of unsaturation determines the total number of pi bonds in a given structure and calculates the degree of unsaturation.

Degree of unsaturation= $\frac{\text{2C+2+N-H-X}}{\text{2}}$

• C= Total number of carbon atoms in the molecule
• N= Total number of nitrogen atoms in the molecule
• X= Total number of halogen atoms in the molecule

Molecular formula, C₈H₁₆ in present degree of unsaturation= 1

So the possible structures are:

Possible structures with molecular ion at m/z = 112