Halogen Derivatives - Chemistry Textbook PDF

10. HALOGEN DERIVATIVES Can you recall ? CH3 - CH2 - X CH2 = CH - X Identify the functional group (Haloalkane) (Haloalkene) in the following compounds....

10. HALOGEN DERIVATIVES Can you recall ? CH3 - CH2 - X CH2 = CH - X Identify the functional group (Haloalkane) (Haloalkene) in the following compounds. HC ≡ C - X X i. ii. CCl2F2 Br (Haloalkyne) (Haloarene) (Benzyl bromide) (Freon - 12) b. On the basis of number of halogen atoms, iii. Cl iv. Cl - CH = CCl2 halogen derivatives are classified as mono, Cl Cl di, tri or poly halogen compounds. (Westrosol) X Cl Cl CH3 - CH2 - X Cl (Hexachlorobenzene) Monohalogen compounds v. Cl CH3 - CH - X CH2 - CH2 X Cl Cl X X X X Cl Cl Dihalogen compounds Cl (Benzene hexachloride) (Hexachlorocyclohexane) X CH2 - CH - CH2 X The parent family of organic compounds X X X is hydrocarbon. Replacement of hydrogen X atom/s in aliphatic or aromatic hydrocarbons Trihalogen compounds by halogen atom/s results in the formation of halogen derivatives of hydrocarbons. We will consider classification of mono halogen derivatives in more detail. In this chapter we will study halogen derivatives in a systematic way. 10.1.1 Classification of monohalogen compounds : Monohalogen compounds are Internet my friend further classified on the basis of position of Find out the structures halogen atom and the type of hybridization of of two thyroid hormones T3 carbon to which halogen is attached. (triiodothyronine) and T4 (thyroxine). a. Alkyl halides or haloalkanes : In alkyl How do these help our body ? halides or haloalkanes the halogen atom is 10.1 Classification of halogen derivatives : bonded to sp3 hybridized carbon which is a part of saturated carbon skeleton. Alkyl Halogen derivatives of hydrocarbons are halides may be primary, secondary or tertiary classified mainly in two ways. depending on the substitution state of the a. On the basis of hydrocarbon skeleton to carbon to which halogen is attached : (Refer which halogen atom is bonded, the halogen to Std. XI Chemistry Textbook, section 14.3). derivatives are classified as haloalkanes, haloalkenes, haloalkynes and haloarenes. 210  R d. Vinylic halides : In vinylic halides halogen R - CH2- X R - CH- R R − C − X atom is bonded to a sp2 hybridized carbon X R atom of aliphatic chain. Vinylic halide is a haloalkene. Primary Secondary Tertiary halide halide halide X (1 halide) 0 (2 halide) 0 (3 halide) 0 CH2= CH - X b. Allylic halides : In allylic halides, halogen e. Haloalkyne : When a halogen atom is atom is bonded to a sp3 hybridized carbon bonded to a sp hybridized carbon atom it is atom next to a carbon-carbon double bond. a haloalkyne. X CH ≡ C - X CH2= CH - CH2 - X f. Aryl halides or haloarenes : In aryl halides, halogen atom is directly bonded to c. Benzylic halide : In benzylic halides the sp2 hybridized carbon atom of an aromatic halogen atom is bonded to a sp3 hybridized ring. carbon atom which is further bonded to an CH3 aromatic ring. X X CH3 CH2 - X C X CH3 Table 10.1 Names of some halogen derivatives Formula Common name IUPAC name CH2Cl2 Methylene chloride Dichloromethane CH3CH2Br Ethyl bromide Bromoethane CH3CH(Cl)CH3 Isopropyl chloride 2-Chloropropane (CH3)2 CH - CH2Br Isobutyl bromide 1-Bromo-2-methylpropane (CH3)3 C Br Tert-butyl bromide 2-Bromo-2-methylpropane (CH3)3 C CH2Cl Neopentyl chloride 1-Chloro-2, 2-dimethyl pro- pane CH2 = CH - Cl Vinyl chloride 1-Chloroethene CH2 = CH - CH2Br Allyl bromide 3-Bromopropene CH ≡ C - Cl Chloro acetylene Chloroethyne CH2I Benzyl iodide Iodophenylmethane I p-Iodotoluene 1-Iodo-4-methyl benzene or 4-Iodotoluene H3C Cl m-dichlorobenzene 1, 3-dichlorobenzene Cl 211