Chemistry · Ch 6 — Haloalkanes and Haloarenes
Compounds Containing sp² C—X Bond
Compounds Containing sp² C—X Bond
When the halogen atom is bonded to an -hybridised carbon instead of an one, the monohalo compound falls into one of two classes.
(a) Vinylic Halides
A vinylic halide has the halogen bonded directly to an -hybridised carbon that is itself part of a carbon–carbon double bond:
The halogen sits right on one of the doubly-bonded carbons — not on a carbon next to the double bond (that would make it allylic instead). This holds whether the double bond is part of an open chain or part of a ring.
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your NCERT textbook's own diagram.
CH2=CH-X, the simplest vinylic halide: the halogen is bonded directly to the sp2 carbon that is itself part of the C=C double bond, not to a carbon next to it (that neighbouring-carbon case is allylic instead). This direct C(sp2)-X bond is why vinylic and aryl halid …
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your NCERT textbook's own diagram.
The ring form of a vinylic halide: X sits directly on the sp2 ring carbon that is itself part of the ring's own C=C double bond, not on a carbon next to it -- the cyclic counterpart to the open-chain …
(b) Aryl Halides
An aryl halide has the halogen bonded directly to an -hybridised carbon of an aromatic ring — the halogen is attached straight to a ring carbon, unlike a benzylic halide where the halogen-bearing carbon sits just outside the ring. Substituted aromatic rings, such as one carrying both a methyl group and the halogen at different ring positions, are also grouped under aryl halides as long as X is bonded directly to a ring carbon.
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your NCERT textbook's own diagram.
X bonded directly to an aromatic-ring carbon: a plain aryl halide (Ph-X) and a substituted example carrying an extra methyl group on the ring, showing that any halogen-on-ring-carbon compound counts as an aryl halide re …
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