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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 · 2016 · Paper II

Q5(d). Photodecarbonylation of diphenylcyclopropenone

Question

Formulate the product(s) and give the mechanism for the following reaction:
[structure] → (hν)

Answer in brief

PhC≡CPh + ⁻:C≡O:⁺ diphenylacetylene and carbon monoxide, by photochemical decarbonylation through a biradical (or concerted cheletropic loss of CO).

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Topic notes: organic photochemistry and Norrish reactions, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coverscarbon monoxidediphenylacetylenephotodecarbonylationn→π* excited statering strain

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