Interhalogen compounds

student will able to learn type of interhalogen compounds, synthesis and structure

1. MAHATMA GANDHI,ARTS, SCIENCE AND LATE N.P.COMMERCE COLLEGE ARMORI DIST. GADCHIROLI B. SC.II SEM. III - PRESENTATION UNIT-I INTERHALOGEN COMPOUNDS CONTENTS 1)DEFINITION 2)TYPES OF I. C. 3)SYNTHESIS 4)PROPERTIES 5)STRUCTURE S.M.SONTAKKE Assistant professor CHEMISTRY

2. INTERHALOGEN COMPOUNDS DEFINITION Compounds Produced By the Direct Combination of two halogen atom of different electronegativity are called as inter halogen compounds. In General they are represented as XYn Where n= 1,3,5 or 7 X= Halogen atom with lower electronegativity and bigger size Y= halogen atom with higher electronegativity and smaller size Examples ClF,BrF,BrF3,IF5,IF7, Halogen F Cl Br I EN Decreases Size Increases

3. Types of Inter halogen Compounds AX AX 3 AX 5 AX 7 Diatomic IC Tetra-atomic IC Hexa -atomic IC Octa -atomic IC e.g. ClF , BrF , IF e.g. ClF 3 BrF 3 IF 5 BrF 5 IF 7 Inter halogen Compounds are named as name of first halogen followed by name of second halide with number of atoms i.e. ending – ine of halogen is replaced by –de e.g. i) ClF is named as Chlorine monofluoride . ii) ClF 3 is named as Chlorine trifluoride . iii) BrF 5 is named as Bromine pentafluoride . iv) IF 7 is named as Iodine heptafluoride .

4. Methods of Synthesis of Inter halogen Compounds. There are two general methods of synthesis of Interhalogen Compound. By direct Combination of two halogen molecules at particular temperature condition. e.g. when equal volume of chlorine and fluorine react together at 473K , chlorine monofluoride formed. 2) Halogen molecule react with lower IC to give higher IC at particular temperature condition. e.g. molecular fluorine react with iodine pentafluoride at 543K to give higher IC iodine hepta fluoride

5. Synthesis of Chlorine monofluoride :- ( ClF ) Chlorine monofluoride is prepared by the direct combinition of molecular chlorine with fluorine at 473K. Reaction:- F 2 + Cl 2 2ClF Chlorine monofluoride is a colorless gas with melting point117K. It is covalent molecule and diamagnetic in nature. It is more reactive than normal halogen as the molecule is polar in nature.

6. Synthesis of Iodine mono chloride ( ICl ) Iodine mono chloride is formed by passing chlorine gas over solid iodine at temperature 273K. Reaction:- It is red-brown chemical compound melt near room temperature. ICl is highly polar molecule due to difference in electronegativity. In organic synthesis, estimation of Iodine number of oils as a source of I+.

7. Synthesis of Bromine trifluoride (BrF 3 ) Bromine trifluoride is produced by the mixing of bromine vapor and fluorine in a stream of nitrogen at 293K Reaction:- It is straw colored liquid with pungent odor It is powerful fluorinating agents It is used to produce uranium hexafluoride UF6 in the processing and reprocessing of nuclear fuel.

8. Synthesis of Chlorine trifluoride (ClF 3 ) Chlorine trifluoride is synthesized by the mixing of molecular chlorine and fluorine at 473-573K in copper vessel. Reaction:- Cl 2 + 3F 2 2ClF 3 Chlorine trifluoride is a colorless gas which condenses to give pale green liquid. It is hydrolyzed by water to give ClOF . When chlorine trifluoride is reacted with molecular fluorine it gives higher inter halogen compound ClF 5. Shape of Chlorine trifluoride is bent T type due to two lp of electrons.

9. Synthesis of Bromine pentafluoride ( BrF 5 ) Bromine pentafluoride is prepared by the direct reaction of molecular bromine with excess of fluorine at temperature 423K. Reaction:- Bromine pentafluoride is pale yellow liquid. It is an extremely effective fluorinating agent, converting most uranium compound to the hexafluoride at room temperature.

10. Synthesis of Iodine pentafluoride ( IF 5 ) Iodine pentafluoride is prepared by the direct combination of Iodine with excess of fluorine. Reaction:- I 2 + 5F 2 2IF 5 Iodine pentafluoride is a colorless liquid with melting point 283K. It is good conductor of electricity. It is hydrolyzed by water to give halogen acid and oxyacid of larger halogen atom. Iodine pentafluoride has square pyramidal shape with one lp of electron.

11. Synthesis of Iodine heptafluoride (IF 7 ) Iodine heptafluoride is synthesized by passing a mixture of iodine pentafluoride vapors and fluorine through a platinum tube at 573K. Reaction:- Iodine heptafluoride is a colorless gas. It is used as strong oxidizing agent. It is used to prepare periodic acid.

12. Applications of Inter halogen Compounds Inter halogen compounds are used as non-aqueous solvents in many chemical reaction. They are used as Catalyst in chemical reaction. Inter halogen compounds are used as fluorinating agents in several chemical reactions.

13. Structure and Bonding in Interhalogen Compounds Diatomic IC (AX type) ClF , ICl , IBr etc. Structure and Bonding in Interhalogen Compounds can be explain on the basis of Hybridization. Valence shell EC of Central atom Chlorine is 3s2 3 p5 Diatomic IC 7+7=14 e/8 i.e. 1bp and 3lp Central atom Chlorine undergo sp3 Hybridization According to VSEPR theory, Shape of ClF is linear as it contain two atoms only Out of four hybridized orbital, three contain lp of electron and one is bp having linear structure

14. B) Structure and Bonding in Tetra-atomic IC (AX3 type) e.g. ClF 3 , BrF 3 , IF 3 , ICl 3 Structure of Chlorine tri-fluoride can be explain on the basis of hybridization. In, ClF 3 central atom Chlorine has valence shell EC 3s 2 3p 5 In tetra-atomic IC 7X4=28e/8 i.e. 3bp and 2lp Central atom Chlorine undergo sp3d hybridization resulting T rigonal bipyramidal geometry According to VSEPR theory, shape of ClF 3 is bent T shape as it contain three bp and two lp Out of five hybridized orbital three contain bp and two contain lp

15. C) Structure and Bonding in Hexa -atomic IC (AX 5 type) e.g. BrF 5 IF 5 etc. Structure and bonding in IF 5 can be explain on the basis of Hybridization In IF 5 Central atom Iodine has valence shell EC 5S 2 5P 5 In hexa -atomic IC , IF 5 7x6=42/8=5bp and one lp In IF 5 ,Central atom Bromine undergo sp3d2 hybridization resulting Octahedral geometry According to VSEPR theory, Shape of IF 5 is Square pyramidal due to 5 bp and one lp Out of six hybridized orbital five are bp and one is lp decreasing bond angle to 81.9

16. D) Structure and Bonding in Octa -atomic IC (AX 7 type) e.g. IF 7 Structure and bonding in IC can be explain on the basis of hybridization In IF 7, Central atom Iodine has valence shell EC 5s25p2 In octa -atomic IC ,like IF 7 8x7=56/8 i.e. 7bp and zero lp . In IF 7 central atom iodine undergo sp3d3 hybridization resulting in pentagonal bipyramidal geometry. According to VSEPR theory lp is zero therefore IF 7 has regular shape i.e. pentagonal bipyramidal shape. In IF 7 all the seven hybridized orbital forms seven covalent bond with fluorine atom having regular shape.

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