Children’s club lecture 20-04-2010 K. Suthagar TYPES OF HYBRIDIZATION AND GEOMETRY OF MOLECULES 1.

Children’s club lecture 20-04-2010K. Suthagar

TYPES OF HYBRIDIZATION AND GEOMETRY OF MOLECULES

1

CHEMICAL CHEMICAL BONDINGBONDINGCHEMICAL CHEMICAL BONDINGBONDING

Chemical BondingChemical BondingProblems and questions —Problems and questions —How is a molecule or How is a molecule or

polyatomic ion held polyatomic ion held together?together?

Why are atoms distributed at Why are atoms distributed at strange angles?strange angles?

Why are molecules not flat?Why are molecules not flat?Can we predict the structure?Can we predict the structure?How is structure related to How is structure related to

chemical and physical chemical and physical properties?properties?

4

Chemical bonds are the attractive forces that hold atoms together in the form of compounds. They are formed when electrons are shared between two atoms. There are 3 types of bonds...covalent bonds, polar covalent bonds and ionic bonds

Chemical Bonds

5

Important concepts in chemical bonding and molecular structure

The attractive force which holds together the constituent particles (atoms, ions or molecules) in chemical species is known as chemical bond.

Tendency of atoms of various elements to attain stable configuration of eight electrons in their valence shell is the cause of chemical combination.

The principle of attaining a maximum of eight electrons in the valence shell or outermost shell of atoms is known as octet rule.

The tendency of an atom to take part in chemical combination is determined by the number of valence electrons (electrons in the outermost shell of an atom).

The atoms acquire the stable noble gas configuration of having eight electrons in the outermost shell (called octect rule) by mutual sharing or by transfer of one or more electrons.

The valency (number of electrons an atom loses, gains or mutually shares to attain noble gas configuration) of an element is either equal to the number of valence electrons or equal to 8 minus the number of valence electrons.

Review of Chemical BondsReview of Chemical BondsThere are 3 forms of bonding:There are 3 forms of bonding:__________________—complete —complete transfer transfer of of

1 or more electrons from one 1 or more electrons from one atom to another (one loses, the atom to another (one loses, the other gains) forming oppositely other gains) forming oppositely charged ions that attract one charged ions that attract one anotheranother

__________________——some valence some valence electrons electrons sharedshared between atoms between atoms

__________________ – holds atoms of a – holds atoms of a metal togethermetal together

Most bonds are Most bonds are somewhere in somewhere in between ionic and between ionic and covalent.covalent.

7

General Properties of Covalent Compound

The covalent compounds do not exist as ions but they exist as molecules.

The melting and boiling points of covalent compounds are generally low.

Covalent compounds are generally insoluble or less soluble in water and other polar solvents.. However, these are soluble in non- polar solvents.

Covalent compounds do not give ions in solution, these are poor conductors of electricity in the fused or dissolved state.

Characteristics of Covalent Compounds

Covalent compounds are formed by the mutual sharing of electrons. There is no transfer of electrons from one atom to another and therefore no charges

are created on the atom. No ions are formed. These compounds exist as neutral molecules and not as ions. Although some of the covalent molecules exist as solids, they do not conduct electricity in fused or molten or dissolved state.

ii) They possess low melting and boiling points. This is because of the weak intermolecular forces existing between the covalent molecules. Since, no strong coulombic forces are seen; some of covalent molecules are volatile in nature. Mostly covalent compounds possess low melting and boiling points.

iii) Covalent bonds are rigid and directional therefore different shapes of covalent molecules are seen.

iv) Most of the covalent molecules are non polar and are soluble in nonpolar (low dielectric constant) solvents like benzene, ether etc and insoluble in polar solvents like water. Carbon tetrachloride (CCl4) is a covalent nonpolar molecule and is soluble in benzene.

8

Co-Ordinate Covalent Bond

Covalent type bond in which both the electrons in the shared pair come from one atom is called a coordinate covalent bond. Co-ordinate covalent bond is usually represented by an arrow () pointing from donor to the acceptor atom.

Co-ordinate Covalent bond is also called as dative bond, donor – acceptor bond, semi- polar bond or co-ionic bond. The electrostatic force of attraction which holds the oppositely charged ions together is known as ionic bond or electrovalent bond.

Ionic compounds will be formed more easily between the elements with comparatively low ionization enthalpy and elements with comparatively high negative value of electron gain enthalpy.

9

General Properties of Ionic Compounds

Ionic compounds usually exist in the form of crystalline solids. They have high melting and boiling points and this ionic compounds are generally soluble in water and other polar solvents having high dielectric constants. Ionic compounds are good conductors of electricity in the solutions or in their molten states.

The chemical reactions of ionic compounds are characteristic of the constituent ions and are known as ionic reactions. In ionic - compounds, each ion is surrounded by oppositely charged ions uniformly distributed all around the ion and therefore, electrical field is nondirectional.

10

Electronegativity Difference

If the difference in electronegativities is between: 1.7 to 4.0: Ionic 0.3 to 1.7: Polar Covalent 0.0 to 0.3: Non-Polar Covalent

Example: NaClNa = 0.8, Cl = 3.0Difference is 2.2, sothis is an ionic bond!

Ionic BondsIonic BondsIonic BondsIonic Bonds All those ionic compounds were made All those ionic compounds were made

from ionic bonds. We’ve been through from ionic bonds. We’ve been through this in great detail already. Positive this in great detail already. Positive cations and the negative anions are cations and the negative anions are attracted to one another!)attracted to one another!)

Therefore, ionic compounds are Therefore, ionic compounds are usually between metals and usually between metals and nonmetals (opposite ends of the nonmetals (opposite ends of the periodic table).periodic table).

Electron Electron Distribution Distribution in Moleculesin Molecules

Electron Electron Distribution Distribution in Moleculesin Molecules

Electron distribution is Electron distribution is depicted withdepicted with Lewis Lewis (electron dot) (electron dot) structuresstructures

This is how we This is how we can decide how can decide how many atoms will many atoms will bond covalently! bond covalently!

(In ionic bonds, (In ionic bonds, it was decided it was decided with charges)with charges)G. N. Lewis G. N. Lewis

1875 - 19461875 - 1946

Bond and Lone Bond and Lone PairsPairsBond and Lone Bond and Lone PairsPairs

Valence electrons are Valence electrons are distributed as shared ordistributed as shared or BOND PAIRSBOND PAIRS and unshared and unshared oror LONE PAIRS.LONE PAIRS.

•

••

•

••

H Cllone pair (LP)

shared orbond pair

This is called a This is called a LEWIS LEWIS structure.structure.

Bond FormationBond FormationBond FormationBond Formation

A bond can result from anA bond can result from an overlapoverlap of of atomic orbitals on neighboring atoms.atomic orbitals on neighboring atoms.

ClH H Cl••

••

••

••

••

••

+

Overlap of H (1s) and Cl (2p)Note that each atom has a single, unpaired electron.Note that each atom has a single, unpaired electron.

Review of Valence Review of Valence ElectronsElectronsReview of Valence Review of Valence ElectronsElectronsRemember from the electron chapter Remember from the electron chapter

that valence electrons are the that valence electrons are the electrons in the OUTERMOST energy electrons in the OUTERMOST energy level… that’s why we did all those level… that’s why we did all those electron configurations!electron configurations!

B is 1sB is 1s22 2s 2s22 2p 2p11; so the outer energy ; so the outer energy level is 2, and there are 2+1 = 3 level is 2, and there are 2+1 = 3 electrons in level 2. These are the electrons in level 2. These are the valence electrons!valence electrons!

Br is Br is [Ar] 4s[Ar] 4s22 3d 3d1010 4p 4p55

How many valence electrons are How many valence electrons are present?present?

Review of Valence Review of Valence ElectronsElectronsReview of Valence Review of Valence ElectronsElectrons

Number of valence electrons of a main (A) Number of valence electrons of a main (A) group atom = Group numbergroup atom = Group number

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Lewis electron dot symbols

The symbols of the element is written first. This represents the nucleus of the element with all the inner electrons that do not take part in the bond formation.

The valence electrons are then written as dots or (small cross marks) around the symbol. They are spread in a pair on four sides of the symbol.

In case of ions the charge is shown with the symbol

Electron dot symbol representation of F2

Valence Shell Electron Pair Repulsion (VSEPR) theory

The shape of a molecule can be determined from the arrangement and repulsions between the electron pairs present in the valence shell of central atom of that molecule.

ii) There are two types of valence shell electron pairs viz., i) Bond pair and ii) Lone pair

iii) The electron pairs in the valence shell the repel each other and determines the shape of the molecule. The magnitude of the repulsion depends upon the type of electron pair.

iv) The bond pair is attracted by nuclei they occupy less space and hence it causes less repulsion. Whereas, the lone pairs are only attracted by one nucleus and hence occupy more space. As a result, the repulsion caused by them is greater.

v) The order of repulsion between different types of electron pairs is as follows :Lone pair - Lone pair > Lone Pair -Bond pair > Bond pair- Bond pair

vi) When the valence shell of central atom contains only bond pairs, the molecule gets sym-metrical structure, whereas the symmetry is distorted when there are lone pairs along with bond pairs.

vii) The bond angle decreases due to the presence of lone pairs.

viii) The repulsion increases with increase in the number of bonds between two atoms

ix) Triple bond causes more repulsion then double bond which in turn cause more repulsion than single bonds

x) The repulsion between electron pairs increases with increase electronegativity of central atom and hence the bond angle increases.

xi) Shapes of molecules can be predicted from the number of electron pairs in the valence shell of central atom

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Lewis dot structures of Cl2 , O 2 and ethane molecules

Steps for Building a Dot Steps for Building a Dot StructureStructureSteps for Building a Dot Steps for Building a Dot StructureStructure

Ammonia, NHAmmonia, NH33

1. Decide on the central atom; never H. 1. Decide on the central atom; never H. Why?Why?

If there is a choice, the central atom is atom of If there is a choice, the central atom is atom of lowest affinity for electrons. lowest affinity for electrons. (Most of the time, this is (Most of the time, this is the the least electronegative least electronegative

Therefore, N is central on this oneTherefore, N is central on this one

2. Add up the number of valence electrons 2. Add up the number of valence electrons that can be used.that can be used.

H = 1 and N = 5H = 1 and N = 5

Total = (3 x 1) + 5 Total = (3 x 1) + 5

= 8 electrons / 4 pairs= 8 electrons / 4 pairs

3.3. Form a single bond Form a single bond between the central atom and between the central atom and each surrounding atom (each each surrounding atom (each bond takes 2 electrons!)bond takes 2 electrons!)

H H

H

N

Building a Dot StructureBuilding a Dot Structure

H••

H

H

N

4.4. Remaining electrons form LONE PAIRS to Remaining electrons form LONE PAIRS to complete the octet as needed (or duet in the case of H).complete the octet as needed (or duet in the case of H).

3 BOND PAIRS and 1 LONE PAIR.3 BOND PAIRS and 1 LONE PAIR.

Note that N has a share in 4 pairs (8 electrons), Note that N has a share in 4 pairs (8 electrons), while H shares 1 pair.while H shares 1 pair.

5.5. Check to make sure there are 8 electrons around each Check to make sure there are 8 electrons around each atom except H. H should only have 2 electrons. This atom except H. H should only have 2 electrons. This includes SHARED pairs. includes SHARED pairs.

Carbon Dioxide, COCarbon Dioxide, CO22Carbon Dioxide, COCarbon Dioxide, CO22

1. Central atom = 1. Central atom =

2. Valence electrons =2. Valence electrons =

3. Form bonds.3. Form bonds.

O OC4. Place lone pairs on outer atoms.4. Place lone pairs on outer atoms.

This leaves 12 electrons (6 pair).This leaves 12 electrons (6 pair).

5. Check to see that all atoms have 8 electrons around it except for 5. Check to see that all atoms have 8 electrons around it except for H, which can have 2.H, which can have 2.

C 4 e-C 4 e-O 6 e- X 2 O’s = 12 e-O 6 e- X 2 O’s = 12 e-Total: 16 valence Total: 16 valence electronselectrons

Carbon Dioxide, COCarbon Dioxide, CO22Carbon Dioxide, COCarbon Dioxide, CO22

••O OC

•• ••

••••••

••O OC

•• ••

••••••

••O OC

•• ••

••

••O OC

•• ••

••

6. There are too many electrons in our drawing. We 6. There are too many electrons in our drawing. We must form DOUBLE BONDS between C and O. must form DOUBLE BONDS between C and O. Instead of sharing only 1 pair, a double bond shares 2 Instead of sharing only 1 pair, a double bond shares 2 pairs. So one pair is taken away from each atom and pairs. So one pair is taken away from each atom and replaced with another bond.replaced with another bond.

C 4 e-C 4 e-O 6 e- X 2 O’s = 12 e-O 6 e- X 2 O’s = 12 e-Total: 16 valence electronsTotal: 16 valence electrons

How many are in the How many are in the drawing?drawing?

Double and even Double and even triple bonds are triple bonds are commonly commonly observed for C, N, observed for C, N, P, O, and SP, O, and S

••O OC

•• ••

••

••O OC

•• ••

••

HH22COCO

SOSO33

CC22FF44

Violations of the Octet RuleViolations of the Octet Rule(Honors only)(Honors only)

Violations of the Octet RuleViolations of the Octet Rule(Honors only)(Honors only)

Usually occurs with B and Usually occurs with B and elements of higher periods. elements of higher periods. Common exceptions are: Be, Common exceptions are: Be, B, P, S, and Xe. B, P, S, and Xe.

BF3BF3

SF4SF4

Be: 4Be: 4

B: 6B: 6

P: 8 OR 10P: 8 OR 10

S: 8, 10, OR 12S: 8, 10, OR 12

Xe: 8, 10, OR 12Xe: 8, 10, OR 12

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Significance of Lewis Symbols

a) The Lewis symbols indicate the number of electrons in the outermost or valence shellwhich helps to calculate common or group valency.

b) The common valency of an element is either equal to number of dots orvalence electrons in the Lewis symbol or it is equal to 8 minus the number of dots orvalence electrons.

c) The bond formed by mutual sharing of electrons between the combining atomsof the same or different elements is called a covalent bond.

d) If two atoms share one electron pair, bond is known as single covalent bond and isrepresented by one dash (–).

e) If two atoms share two electron pairs, bond is known as double covalent bond and isrepresented by two dashes (=).

f) If two atoms share three electron pairs, bond is known as triple covalent bond and isrepresented by three dashes ( º).

g) The formal charge of an atom in a polyatomic ion or molecule is defined as thedifference between the number of valence electrons in an isolated (or free) atomand the number of electrons assigned to that atom in a Lewis structure.

MOLECULAR MOLECULAR GEOMETRYGEOMETRYMOLECULAR MOLECULAR GEOMETRYGEOMETRY

VSEPRVSEPR VValence alence SShell hell EElectron lectron PPair air

RRepulsion theory.epulsion theory.

Most important factor in Most important factor in determining geometry is determining geometry is relative relative repulsion between repulsion between electron pairs.electron pairs.

Molecule adopts the Molecule adopts the shape that minimizes shape that minimizes the electron pair the electron pair repulsions.repulsions.

Molecule adopts the Molecule adopts the shape that minimizes shape that minimizes the electron pair the electron pair repulsions.repulsions.

MOLECULAR GEOMETRYMOLECULAR GEOMETRYMOLECULAR GEOMETRYMOLECULAR GEOMETRY

Some Common Some Common GeometriesGeometries

LinearLinear

Trigonal Trigonal PlanarPlanar TetrahedralTetrahedral

Structure Determination by VSEPRStructure Determination by VSEPRStructure Determination by VSEPRStructure Determination by VSEPR

Water, HWater, H22OOThe electron pair geometry The electron pair geometry is is TETRAHEDRALTETRAHEDRAL

The electron pair geometry The electron pair geometry is is TETRAHEDRALTETRAHEDRAL

The molecular The molecular geometry is geometry is BENTBENT..

The molecular The molecular geometry is geometry is BENTBENT..

H O H••

••

H O H••

••

2 bond pairs2 bond pairs

2 lone pairs2 lone pairs

Structure Determination by Structure Determination by VSEPRVSEPRStructure Determination by Structure Determination by VSEPRVSEPR

Ammonia, NHAmmonia, NH33

The electron pair geometry is tetrahedral.The electron pair geometry is tetrahedral.

H

H

H

lone pair of electronsin tetrahedral position

N

The The MOLECULAR GEOMETRYMOLECULAR GEOMETRY — the positions of — the positions of

the atoms — is the atoms — is TRIGONAL TRIGONAL PYRAMIDPYRAMID..

The The MOLECULAR GEOMETRYMOLECULAR GEOMETRY — the positions of — the positions of

the atoms — is the atoms — is TRIGONAL TRIGONAL PYRAMIDPYRAMID..

Bond PolarityBond PolarityBond PolarityBond Polarity

HCl is HCl is POLARPOLAR because it because it has a positive end and a has a positive end and a negative end. (difference negative end. (difference in electronegativity)in electronegativity)

Cl has a greater share Cl has a greater share in bonding electrons in bonding electrons than does H.than does H.

Cl has a greater share Cl has a greater share in bonding electrons in bonding electrons than does H.than does H.

Cl has slight negative charge Cl has slight negative charge (-(-)) and and H has slight positive charge H has slight positive charge (+ (+ ))

H Cl••

••

+ -••H Cl

••

••

+ -••

This is why oil and water will not This is why oil and water will not mix! Oil is nonpolar, and water is mix! Oil is nonpolar, and water is polar.polar.

The two will repel each other, and The two will repel each other, and so you can not dissolve one in the so you can not dissolve one in the otherother

Bond PolarityBond PolarityBond PolarityBond Polarity

Bond PolarityBond PolarityBond PolarityBond Polarity

““Like Dissolves Like”Like Dissolves Like”Polar dissolves Polar dissolves

PolarPolarNonpolar dissolves Nonpolar dissolves

NonpolarNonpolar

Put on your 3-D glasses!

HybridizationUses modifications of molecular models to account for

observed structures of molecules or ionsIs a mixing of the native atomic orbitals to form special

hybrid orbitals for bondingThe special orbitals will then strive to be as far away from

each other in space as they can be

Types of Hybridizationsp3

sp2

spdsp3

d2sp3

Types of BondsSigma (σ) bondsEnd-to-end bondingThere is an overlapOne in every type of bond

Pi (π) bondsSide-to-side bondingThere is no overlap1 in a double bond2 in a triple bond

Native s orbital

x

z

y

Native p orbitals

x

z

yx

z

y

x

z

y

px

py

pz

Hybrid sp3 orbitals

x

z

y

x

z

y

x

z

y

x

z

y

Hybrid sp3 orbitals

x

z

y

Hybrid sp3 orbitals

x

z

y

sp3 orbitals4 effective pairs109.5°, 107.3°(w/1 lone pair), or 104.5° (w/2 lone pairs)tetrahedral, pyramidal, or bent

Hybrid sp3 orbitals

CH4

x

z

y 4 σ bonds inthe molecule

CH

H

HH

overlapping orbitals

48

sp3 hybridization –Methane sp3 hybridization –Methane

49

Orbital picture and structure of methane

Native s orbital

x

z

y

Native p orbitals

x

z

yx

z

y

x

z

y

px

py

pz

Leave this one as is

Hybrid sp2 orbitals

x

z

y

x

x

z

y

z

y

Hybrid sp2 orbitals

x

z

y

sp2 orbitals3 effective pairs120°trigonal planar

Hybrid sp2 orbitals

x

z

y

sp2 orbitals3 effective pairs120°trigonal planar

Remember the un-hybridized p orbital?

Hybrid sp2 orbitals

x

z

y

x

z

yC2H4

side-by-side orbitalsoverlapping orbitals

C C

H

HH

H

5 σ bonds1 π bondin molecule

56

sp2 hybridization Ethene

57

Orbital picture of ethylene

Native s orbital

x

z

y

Native p orbitals

x

z

yx

z

y

x

z

y

px

py

pz

Leave this one as is

Leave this one as is

Hybrid sp orbitals

x

z

y

x

z

y

Hybrid sp orbitals

x

z

y

x

z

y

sp orbitals2 effective pairs180°linear

Hybrid sp orbitals

x

z

y

x

z

y

sp orbitals2 effective pairs180°linear

Remember the un-hybridized p orbitals?

Hybrid sp orbitals

C2H2

x

z

y

x

z

y

x

z

y

x

z

y

overlapping orbitals side-by-side orbitals

Hybrid sp orbitals

C2H2

x

z

y

x

z

y

x

z

y

x

z

y

H HCC

65

sp hybridization – Ethyne

66

Orbital picture of ethyne

67

Hybridization and molecular shapes of some molecules involving sporbitals

68

Hybridization involving d orbitals sp3d hybridization sp3d2 hybridization sp3d3 hybridization dsp2 hybridization

Formation of five sp3d hybrid orbitals, which adopt trigonal bipyramidal geometry Phosphorus penta fluoride involves sp3d-Hybridization

sp3d hybridization

69

Geometry of PF5 molecule

Structure of PF5

Formation of PF5 molecule involving sp3d Hybridization

70

sp3d2 Hybridization - Geometry of SF6 molecule

Octahedral geometry of SF6 molecule

Formation of SF6 molecule involving sp3d2 Hybridization

71

Geometry of IF7 molecule - sp3d3 hybridization

Formation of IF7 molecule involving sp3d3 hybridization

Pentagonal bipyramidal geometry of IF7 molecule

72

dsp2 hybridization Geometry of [Ni(CN)4]2-

Formation of [Ni(CN)4]2- involving dsp2 hybridization

Structure of [Ni(CN)4]2-

Molecular Geometry

bond length, angle determined experimentally

Lewis structures bonding

geometryVSEPR

Valence Shell Electron Pair Repulsion

octahedron 90o bond angles

trigonal bipyramid equatorial 120o

axial 180o

big groups

small groups

tetrahedron 109.5o

trigonal planar 120o

linear 180o

geometry apply to Chemistry

linear 180o

BeCl2

valence e- = 2 + (2 x 7) = 16e-

Cl....

..BeCl....

..

fewer than 8e-

valence pairs on Be bonding e-

linear molecule

two

linear 180o

CO2

valence e- = 4 + (2 x 6) = 16e-

CO....

.. O....

.. CO..

O..

.. ..

valence pairs on C ignore double bondstwo

single and double bonds same

linearmolecular shape

molecular geometry linear

trigonal planar 120o

SO2

valence e- = 6+ (2 x 6) = 18e-

valence pairs on Sthree

one lone pair

molecular geometry

molecular shape bent

trigonal

S O....

..O....

:

SO....

.. O....

..:

SO.....

. O....

:

two bonding pairs

< 120o

tetrahedral 109.5o

CH4

valence e- = 4+ (4 x 1) = 8e-

valence pairs on CfourC HH

H

H109.5o

molecular geometry

molecular shape tetrahedral

tetrahedral

tetrahedral 109.5o

NH3

valence e- = 5+ (3 x 1) = 8e-

valence pairs on Nfour N HH

H

:

< 109.5o

molecular geometry

molecular shape trigonal pyramid

tetrahedral

one lone pair

three bonding pairs

tetrahedral 109.5o

H2O

valence e- = 6+ (2 x 1) = 8e-

valence pairs on Ofour

O HH

::

< 109.5o

molecular geometry

molecular shape bent

tetrahedral

two lone pair

two bonding pairs

bipyramidal 120o and 1800

PCl5

valence e- = 5+ (5 x 7) = 40e-

valence pairs on Pfive

molecular geometry

molecular shape bipyramidal

bipyramidal

P

Cl....

..

Cl....

..

Cl....

..Cl....

..

Cl ......

90o

120o

180o

bipyramidal 120o and 1800

SF4

valence e- = 6+ (4 x 7) = 34e-

valence pairs on Sfive

molecular geometry

molecular shape seesaw

bipyramidal

one lone pair

four bonding pairsS

..F..

..

..F..

..

..F..

....F..

..

:

< 180o

bipyramidal 120o and 1800

ClF3

valence e- = 7+ (3 x 7) = 28e-

valence pairs on Clfive

molecular geometry

molecular shape T

bipyramidal

two lone pair

three bonding pairs

Cl

..F..

..

..F..

....F..

..

::

180o

90o

bipyramidal 120o and 1800

ICl2-

valence e- = 7+ (2 x 7) + e-

valence pairs on Ifive

molecular geometry

molecular shape linear

bipyramidal

three lone pair on I

two bonding pairs

= 22e-

I..Cl..

..

::

..Cl..

..

:

octahedral 90o

BrF5

valence e- = 7+ (5 x 7)

valence pairs on Brsix

molecular geometry

molecular shape square pyramidal

octahedral

= 42e-

one lone pair

five bonding pairs

Br

F....

..F....

..

F....

..

F....

..

F...

. ..:

octahedral 90o

XeF4

valence e- = 8+ (4 x 7)

valence pairs on Xesix

molecular geometry

molecular shape square planar

octahedral

= 36e-

two lone pair

four bonding pairs

Xe

F....

..F....

..F....

..

F....

..

:

:

Cl....

..BeCl....

..

SO....

.. O....

..

S O....

..O....

SO.....

. O....

S

O O

:

CO....

.. O....

.. CO..

O..

.. ..

B

: :

F

:

: : F

:

::

F: ::

C HH

H

H

N HH

H

:

O HH

::

P

Cl....

..

Cl....

..

Cl....

..

Cl....

..

Cl ......

S

..F..

..

..F..

..

..F..

..

..F..

..

:

Cl

..F..

....F..

....F..

..

::

I..Cl..

..

::

..Cl..

..

:

F..

.. ..S

F....

..

F....

..

F....

..F....

..

F...

. ..

Br

F....

..

F....

..

F....

..F....

..

F...

. ..:

Xe

F....

..

F....

..

F....

..

F....

..

:

:

90

91

Geometry of molecules containing one or more lone pairs in central atom

Questions?