HaloAlkanes & HaloArenes

Introduction

In our everyday life we come across many products which are Organic in nature

Chlorine containing antibiotic called Chloramphenicol is a broad spectrum antibiotic used for treating bacterial conjuctivitis like eye infections

Halothane is used as an anesthetic during surgery.

What is common about all these compounds?

The presence of functional group called halogen,  Halogen containing organic compounds occur in nature and few of these are medicinally useful and we can find wide applications in industry as well as in day to day life.

Compounds derived from hydrocarbons  in which one or more hydrogen atom/s are replaced by  halogen atom/s are called halogen  derivatives.

The replacement of one or more hydrogen atoms in a aliphatic hydrocarbons  by halogen atom/s forms haloalkane , commonly known as Alkyl Halide 

                                                                                                   (Here only one Hydrogen is getting replaced so its a monohaloalkane)

The replacement of one or more hydrogen atoms in a aromatic hydrocarbons by halogen atom/s forms haloarene , commonly known as Aryl Halide.

                                                                                                      (Here only one Hydrogen is getting replaced so its a monohaloarene)

These represented by a general formula, R-X. where R may be an alkyl ,aryl or aralkyl group  and 

X is a halogen atom (Fluorine, Chlorine, Bromine ,or Iodine)

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STRUCTURE :

The hybridization of Carbon atoms in Haloalkanes and Haloarenes depend on whether the Carbon atom is bonded to other atom/s by a single bond or multiple bonds

• In Haloalkanes , carbon atom is sp³ hybridised. Thus, Haloalkanes contain Halogen atom/s attached to sp³ hybridised carbon atom of an alkyl group

 The general formula of haloalkanes is C_nH_2n+1X

• In Haloarenes , carbon atom is sp² hybridised. Thus, Haloarenes contain Halogen atom/s attached to sp² hybridised carbon atom of an aryl group

The general formula of haloarenes is ArX or C₆H₅X

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Classification of haloalkanes and haloarenes:

• On the basis of number of halogen atom/s attached to a carbon atom:

 Halogen derivatives of alkanes and benzene are classified into mono, di, tri, tetra etc. substitution products depending upon the number of halogen atom/s present in their structures. 

NOTE : mono means one, di means two and tri means three Halogen atoms

Examples :