Chapter 1: Matter and Measurement

Chapter 1: Matter and Measurement

General Chemistry Principles and Modern Applications Petrucci Harwood Herring 8th Edition Chapter 11: Chemical Bonding II: Additional Aspects Philip Dutton University of Windsor, Canada N9B 3P4 Prentice-Hall 2002

Contents 11-1 11-2 11-3 11-4 11-5 11-6 11-7 Prentice-Hall 2002 What a Bonding Theory Should Do

Introduction to the Valence-Bond Method Hybridization of Atomic Orbitals Multiple Covalent Bonds Molecular Orbital Theory Delocalized Electrons: Bonding in the Benzene Molecule Bonding in Metals Focus on Photoelectron Spectroscopy General Chemistry: Chapter 12 Slide 2 of 47

11-1 What a Bonding Theory Should Do Bring atoms together from a distance. e- are attracted to both nuclei. e- are repelled by each other. Nuclei are repelled by each other. Plot the total potential energy versus distance. -ve energies correspond to net attractive forces. +ve energies correspond to net repulsive forces. Prentice-Hall 2002

General Chemistry: Chapter 12 Slide 3 of 47 Potential Energy Diagram Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 4 of 47

11-2 Introduction to the Valence-Bond Method Atomic orbital overlap describes covalent bonding. Area of overlap of orbitals is in phase. A localized model of bonding. Prentice-Hall 2002 General Chemistry: Chapter 12

Slide 5 of 47 Bonding in H2S Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 6 of 47 Example 11-1 Using the Valence-Bond Method to Describe a Molecular

Structure. Describe the phosphine molecule, PH3, by the valence-bond method.. Identify valence electrons: Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 7 of 47 Example 11-1

Sketch the orbitals: Overlap the orbitals: Describe the shape: Prentice-Hall 2002 Trigonal pyramidal General Chemistry: Chapter 12 Slide 8 of 47

11-3 Hybridization of Atomic Orbitals Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 9 of 47 sp3 Hybridization Prentice-Hall 2002

General Chemistry: Chapter 12 Slide 10 of 47 sp3 Hybridization Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 11 of 47

Methane sp3 hybrid orbitals h1 h2 h3 h4 1 (2s 2 p x 2 p y 2 1 (2 s 2 p x 2 p y 2

1 (2s 2 p x 2 p y 2 1 (2 s 2 p x 2 p y 2 Gbor I. Csonka 2013 2 pz ) 2 pz ) 2 pz )

Tetrahedron in a cube Coordinates: s x y z

1 1 1 1 1 1

-1 -1 1 -1 1 -1

1 -1 -1 1 2 pz ) General Chemistry

Slide 12 /69 Bonding in Methane Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 13 of 47 sp3 Hybridization in Nitrogen

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 14 of 47 Bonding in Nitrogen Prentice-Hall 2002 General Chemistry: Chapter 12

Slide 15 of 47 sp2 Hybridization Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 16 of 47 Orbitals in Boron

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 17 of 47 sp Hybridization Prentice-Hall 2002 General Chemistry: Chapter 12

Slide 18 of 47 Orbitals in Beryllium Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 19 of 47 sp3d and sp3d2 Hybridization

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 20 of 47 Hybrid Orbitals and VSEPR Write a plausible Lewis structure. Use VSEPR to predict electron geometry. Select the appropriate hybridization.

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 21 of 47 11-4 Multiple Covalent Bonds Ethylene has a double bond in its Lewis structure. VSEPR says trigonal planar at carbon. Prentice-Hall 2002

General Chemistry: Chapter 12 Slide 22 of 47 Ethylene + - Prentice-Hall 2002 +

+ - - General Chemistry: Chapter 12 Slide 23 of 47 Ethylene Double bond = 1 C-C + 1 C-C bonds

+ . . . . Notice that the C-C MO is antisymmetric to the molecular plane, it is positive above and negative below the plane. Acetylene Acetylene, C2H2, has a triple bond. VSEPR gives linear at carbon.

C: sp hybrid + + - + + -

There are two bonds in acetylene (ethyne) General Chemistry: Chapter 12 Slide 25 of 47 11-5 Molecular Orbital Theory Atomic orbitals are isolated on atoms. Molecular orbitals span two or more atoms. LCAO Linear combination of atomic orbitals.

1 = 1 + 2 Prentice-Hall 2002 2 = 1 - 2 General Chemistry: Chapter 12 Slide 26 of 47 Combining Atomic Orbitals

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 27 of 47 Molecular Orbitals of Hydrogen Prentice-Hall 2002 General Chemistry: Chapter 12

Slide 28 of 47 Basic Ideas Concerning MOs Number of MOs = Number of AOs. Bonding and antibonding MOs formed from AOs.

e- fill the lowest energy MO first. Pauli exclusion principle is followed. Hunds rule is followed Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 29 of 47 Bond Order Stable species have more electrons in bonding

orbitals than antibonding. No. e- in bonding MOs - No. e- in antibonding MOs Bond Order = 2 Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 30 of 47

Diatomic Molecules of the First-Period BO = (e-bond - e-antibond )/2 BOH += (1-0)/2 = 2 BOH = (2-0)/2 = 1 2 BOHe + = (2-1)/2 = 2 BOHe = (2-2)/2 = 0

2 Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 31 of 47 Molecular Orbitals of the Second Period First period use only 1s orbitals. Second period have 2s and 2p orbitals available. p orbital overlap:

End-on overlap is best sigma bond ().). Side-on overlap is good pi bond ().). Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 32 of 47 Molecular Orbitals of the Second Period Prentice-Hall 2002

General Chemistry: Chapter 12 Slide 33 of 47 Combining p orbitals Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 34 of 47

The energy level diagram for MOs The AOs are on the left and right (yellow and blue), the MOs are in the center (orage and green). MO labels are and for bonding * and * for antbonding. General Chemistry: Chapter 12 Slide 35 of 47 Inversion of the MO energies between N2 and O2

For diatomic molecules with 7 Z the 2p orbital energy is above 2p molecular orbital energy. The latter is filled first. General Chemistry: Chapter 12 Slide 36 of 47 MO Diagrams of 2nd Period Diatomics C2 electron configuration: General Chemistry: Chapter 12

Slide 37 of 47 MO Diagrams of Heteronuclear Diatomics Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 38 of 47 11-6 Delocalized Electrons

General Chemistry: Chapter 12 Slide 39 of 47 Benzene: delocalized bonding Delocalized bonding is not localized between two atoms: instead, each link has a 'fractional double bond order. There is a corresponding 'delocalization energy', identifiable with the

stabilization of the system compared with a hypothetical alternative in which formal (localized) single and double bonds are present. Bond order = 1.5 Delocalization energy = 263.7 kJ mol-1 General Chemistry: Chapter 12 Slide 40 of 47 Benzene, 6 MO energies

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 41 of 47 Benzene 6 MO shapes Non bonding orbitals 6 e-

Bonding orbitals Slide 42 /69 The charge distribution in benzene The electrostatic potential surface. Red: negative charge Blue: positive charge ltalnos Kmia, Kts szerkezet Slide 43 /69

The charge distribution in borazine 6 electrons delocalized system Uneven charge distribution Less stable ltalnos Kmia, Kts szerkezet Slide 44 /69 Pyridine _

6 delocalised electrons _ _ Slide 45 /69 Butadiene 4 delocalised electrons

Slide 46 /69 CO326 delocalised electrons 6e . 2 e from the 2 negative charge + 4 e from the 2p atomic orbitals of the 3 O and 1 C atoms. Slide 47 /69 Ozone

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 48 of 47 11-7 Bonding in Metals Electron sea model Nuclei in a sea of e-. Metallic lustre. Malleability. Force applied

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 49 of 47 Bonding in Metals Band theory. Extension of MO theory. N atoms give N orbitals that are closely spaced in energy.

N/2 are filled. The valence band. N/2 are empty. The conduction band. Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 50 of 47 Band Theory

Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 51 of 47 Semiconductors Prentice-Hall 2002 General Chemistry: Chapter 12

Slide 52 of 47 Photovoltaic Cells General Chemistry: Chapter 12 Slide 53 of 47 Solar cell details General Chemistry: Chapter 12

Slide 54 of 47 Focus on Photoelectron Spectroscopy Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 55 of 47 Chapter 12 Questions

1, 3, 8, 10, 16, 29, 33, 39, 45, 59, 68, 72, 76 Prentice-Hall 2002 General Chemistry: Chapter 12 Slide 56 of 47

Recently Viewed Presentations

  • The age of Enlightenment. - siegkoapeh

    The age of Enlightenment. - siegkoapeh

    The age of Enlightenment. Eighteenth Century France. The objectives of this slide show are: In what ways was the enlightenment and outgrowth of the Scientific Revolution? ... -He stressed "Liberty, equality, and Fraternity" - the motto of the French Revolution.
  • Pre-submittal Meeting Request for Qualifications September 26, 2017,

    Pre-submittal Meeting Request for Qualifications September 26, 2017,

    Joanne McLaughlin, Equal Opportunity Specialist. Equal Opportunity Department. [email protected] ... 71 pipe segments of approximately 8.3 miles. 190 manholes. North Program. 37 pipe segments approximately 4.2 miles. 72 manholes. South Program. 34 pipe segments approximately 4.1 miles.
  • Slayt 1 - file.toraks.org.tr

    Slayt 1 - file.toraks.org.tr

    Key Point The direct pharmacologic effects of nicotine are necessary to, but do not entirely explain, tobacco dependence. Environmental/social stimuli, such as a particular time of day or a particular place (eg, smoking after a meal or in a favorite...
  • Almas Wholesale Bodega In the business of making

    Almas Wholesale Bodega In the business of making

    Camembert Pierrot Manjimup Dried Apples Gnocchi di nonna Alice Alice Mutton Uncle Bob's Organic Dried Pears Ikura 2013 2228.2199999999998 3162 1485 1183.1999999999996 918 1219 874 741 600 651 Sum of Product_Order_Quantity Thüringer Rostbratwurst Côte de Blaye Raclette Courdavault Tarte au...
  • Cells and Tissues of The Adaptive Immune System

    Cells and Tissues of The Adaptive Immune System

    Chapter 2 Morphology of Lymph Node Lymph Nodes and Lymphatic System Dendritic cells capture some microbial antigens and enter lymphatic vessels Adaptive immune responses to antigens that enter through epithelia or are found in tissues are initiated in lymph nodes...
  • CAPS GW - American Academy of Child & Adolescent Psychiatry

    CAPS GW - American Academy of Child & Adolescent Psychiatry

    The Role of Clinicians Stephen J. Cozza, M.D. Professor of Psychiatry Uniformed Services University Child Traumatic Exposures Physical and Sexual Abuse Domestic and Community Violence Medical Trauma Natural Disasters Terrorism War Child Soldiering Displacement/Refugee Status Parental Combat Exposure Torture or...
  • Teoretická příprava - vse.cz

    Teoretická příprava - vse.cz

    Teoretická příprava Výzkum je nutné zakotvit v takové teorii, která se bezprostředně popisuje a vysvětluje zkoumanou oblast jevů. (Např. se jedná o teorii motivace, teorie malých sociálních skupin, teorie organizace, teorie masového působení, psychologie trhu, apod.)
  • Welcome to Handsworth Course Selection 2016/2017 Students entering

    Welcome to Handsworth Course Selection 2016/2017 Students entering

    Welcome to Handsworth Course Selection 2016/2017 Students entering Grade 12