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Indian Forest Service (Mains)

Chemistry optional

  • 2 papers
  • 200 marks each
  • 3 h per paper

Paper II covers organic chemistry and spectroscopy.

Indian Forest Service (Mains), Chemistry optional · 2022 · Paper II

Q8(d). Diphenyl ether and its mass fragments

Question

Phenol and bromobenzene react with copper catalysis to give sweet-smelling A. Explain the structure and the peaks at m/z 170, 141 and 71.

Answer in brief

A is diphenyl ether, Ph–O–Ph; its molecular radical cation occurs at 170, CO/H loss explains 141, and a doubly charged 142-Da fragment can account for 71.

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Topic notes: mass spectrometry: molecular ion, metastable peak and McLafferty rearrangement, with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversUllmann ether synthesisdiphenyl ethermass fragmentationdoubly charged ionloss of CO

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