Question

Which of the following compound does not have sp3C-X bond?

A. CH2=CH-CH2X B. C6H5CH2X C. CH2=CHX D. CH3-CH2X​

Answer 1

The vinyl halide CH2=CHX (option C) does not have an sp3 C-X bond.

• A carbon atom with four sigma bonds is usually said to be sp3 hybridised. A halide (X) bonded to such a carbon can be called an alkyl or aryl halide.
• The presence of one pi bond in a carbon shows that it is sp2 hybridised. This means that the carbon atom is involved in a double bond with another atom. A halide attached to such a carbon is said to be vinylic halide.
• The carbon atoms to which the halide is attached in options A, B and D is sp3 hybridised as it forms only single bonds, that is it forms sigma bonds. These have an sp3 C-X bond.
• The alpha carbon in option C however, forms a double bond with the next carbon and hence is sp2 hybridised.