General Chemistry I (2012) Lecture by B. H. Hong
|
|
- Luke Ellis
- 5 years ago
- Views:
Transcription
1 3.8 The Limitations of Lewis's Theory
2 3.9 Molecular Orbitals The valence-bond (VB) and molecular orbital (MO) theories are both procedures for constructing approximate wavefunctions of electrons. The MO theory can account for electron-deficient compounds, paramagnetic O 2, and many other properties by focusing on electrons delocalized over the whole molecule. The VB theory focuses on electrons on individual bonds between pairs of atoms.
3 3.8 The Limitations of Lewis's Theory MOLECULAR ORBITAL THEORY Fredrich Hund, Robert Mulliken (1966) Box 3.2 Magnetism; diamagnetic, paramagnetic, ferromagnetic, antiferromagnetic, ferrimagnetic Paramagnetic O 2 ; unpaired electron(s) Fig 3.24 Lewis's theory; Valence-bond theory; bond and bond 2 lone pairs on each O occupying the sp 2 hybrid orbitals B 2 H 6 (diborane); electron-deficient compound At least seven bonds (= 14 electrons) are required, but only 12 valence electrons.
4 3.8 The Limitations of Lewis's Theory Linear combination of atomic orbitals molecular orbital (LCAO- MO) method Approximate molecular wavefunctions atomic orbitals by superimposing (mixing) of N c ij and E j are determined by solving the Schrödinger equation
5 3.8 The Limitations of Lewis's Theory Trial wavefunctions for H 2 using two 1s atomic orbitals of H Increased amplitude in the internuclear region bonding Larger volume for electrons lower kinetic energy (particle-in-a-box) Decreased amplitude in the internuclear region & nodal plane antibonding
6 3.8 The Limitations of Lewis's Theory Molecular orbital energy level diagram Fig 3.27 Box 3.3 Photoelectron spectroscopy; orbital energies from E K of photoelectrons
7 3.8 The Limitations of Lewis's Theory
8 3.10 The Electron Configurations of Diatomic Molecules Building-up principle for MO 1. Lower to higher 2. Up to two electrons ( ) per MO; Pauli exclusion principle 3. Hund's rule H 2 : The energy of H 2 is lower than that of the separate H atoms. Fig 3.28 Even the energy of H 2+ is lower than that of the separate H atoms.
9 3.10 The Electron Configurations of Diatomic Molecules
10 3.10 The Electron Configurations of Diatomic Molecules Homonuclear diatomic molecules of Period 2 Linear combination of 10 atomic orbitals; 1. No mixing between AO's of the same atom 2. Significant mixing only between AO's of similar energies and substantial overlap Negligible mixing between the core 1s and the valence 2s and 2p orbitals No MO from 2s 2p mixing due to symmetry
11 3.10 The Electron Configurations of Diatomic Molecules
12 3.10 The Electron Configurations of Diatomic Molecules
13 3.10 The Electron Configurations of Diatomic Molecules Molecular orbital energy level diagram (obtained from the Schrödinger equation) The energy separation of 2s and 2p for O 2 and F 2 are large due to large Z eff pulling 2s-electrons closer. Negligible 2s-2p mixing for O 2 and F 2
14 3.10 The Electron Configurations of Diatomic Molecules
15 3.10 The Electron Configurations of Diatomic Molecules Bond order
16 3.11 Bonding in Heteronuclear Diatomic Molecules Nonpolar covalent bond; Ionic bond (A + B ); Polar covalent bond; if A is more electronegative. Fig 3.33
17 3.11 Bonding in Heteronuclear Diatomic Molecules
18 HF 3.11 Bonding in Heteronuclear Diatomic Molecules No net overlap between H1s and (F2p x or F2p y ) 2 "nonbonding" orbitals
19 3.11 Bonding in Heteronuclear Diatomic Molecules orbital mainly of F2p z (energy level close to F2p z ) orbital mainly of H1s (energy level close to H1s)
20 3.11 Bonding in Heteronuclear Diatomic Molecules CO and NO Fig 3.35 from 2p-2p mixing only
21 3.12 Orbitals in Polyatomic Molecules H 2 O; 1b 1 ; nonbonding, mainly O2p y, lone pair effect 2a 1 ; almost nonbonding
22 3.12 Orbitals in Polyatomic Molecules CH 4 ; 1 of the 4 electron pairs is slightly lower in energy. photoelectron spectroscopy VB-theory; all eight electrons have the same energy. MO-theory; (1a 1 ) 2 (1t 1 ) 6 Lower energy for the 1a 1 electron pair
23 3.12 Orbitals in Polyatomic Molecules C 6 H 6 = 30 atomic orbitals VB theory for delocalized in the ring plane from 24 AO's = 6 (C2s, C2p x, C2p y, H1s) sp 2 hybridization for MO theory for the delocalized 6 from 6 C2p z
24 3.12 Orbitals in Polyatomic Molecules
25 3.12 Orbitals in Polyatomic Molecules Electron-deficient molecules No need to provide one pair of electrons for each pair of atoms Existence of electron-deficient molecules such as B 2 H 6 SF 6 ; hypervalent compounds VB theory needs sp 3 d 2 hybridization with the d-orbitals of S having high energy. MO theory; 10 MO's from 10 AO's (4 valence orbitals of S + 6 2p-orbitals of F pointing toward S)
26 3.12 Orbitals in Polyatomic Molecules SF 6 ; (1a 1 ) 2 (1t 1 ) 6 e 4 ; 8 electrons in bonding orbitals 4 bonding pairs for 6 S F bonds Bond order of S F = electrons in nonbonding orbitals
27 3.12 Orbitals in Polyatomic Molecules Colors of vegetation HOMO; Highest Occupied Molecular Orbital LUMO; Lowest Unoccupied Molecular Orbital Delocalized for conjugated double bonds ( C=C C=C C=C ) Electrons-in-a-large -one-dimensional-box Fig 1.26 Very close energy levels Small HOMO-LUMO gap Visible photons can excite electrons across the gap. Colors! Quiz: Carrot color from b-carotene (C 40 H 56 ), tomato color from lycopene (C 40 H 58 )?
28 3.12 Orbitals in Polyatomic Molecules
29 IMPACT ON MATERIALS: ELECTRONIC CONDUCTION IN SOLIDS 3.13 Bonding in the Solid State Molecular orbitals spread over the entire solid as a huge molecule Bonding in the Solid State Electronic conductor; metals and semiconductors, delocalized electrons as electric current carriers Metallic conductor; electric conductivity decreases with temperature Fig 3.43
30 IMPACT ON MATERIALS: ELECTRONIC CONDUCTION IN SOLIDS 3.13 Bonding in the Solid State
31 IMPACT ON MATERIALS: ELECTRONIC CONDUCTION IN SOLIDS 3.13 Bonding in the Solid State N (~N A ) MO's from N AO's for N electrons 1) Nearly continuous band of energy levels Enormous N value and large "box" 2) N electrons occupying ½N bonding MO's (almost) Zero HOMO-LUMO gap Easy to excite electrons into the conduction band where electrons move freely High conductivity decreasing with T due to increase collisions with the vibrating atoms Insulator; no conductivity
32 IMPACT ON MATERIALS: ELECTRONIC CONDUCTION IN SOLIDS 3.13 Bonding in the Solid State Semiconductor; electric conductivity increases with temperature Superconductor; zero resistance Box 5.2
33 IMPACT ON MATERIALS: ELECTRONIC CONDUCTION IN SOLIDS 3.14 Semiconductors pn-junction diodes
Symmetry and Molecular Orbitals (I)
Symmetry and Molecular Orbitals (I) Simple Bonding Model http://chiuserv.ac.nctu.edu.tw/~htchiu/chemistry/fall-2005/chemical-bonds.htm Lewis Structures Octet Rule Resonance Formal Charge Oxidation Number
More informationValence bond theory accounts, at least qualitatively, for the stability of the covalent bond in terms of overlapping atomic orbitals.
Molecular Orbital Theory Valence bond theory accounts, at least qualitatively, for the stability of the covalent bond in terms of overlapping atomic orbitals. Using the concept of hybridization, valence
More informationChapter 14: Phenomena
Chapter 14: Phenomena p p Phenomena: Scientists knew that in order to form a bond, orbitals on two atoms must overlap. However, p x, p y, and p z orbitals are located 90 from each other and compounds like
More informationValence Bond Theory Considers the interaction of separate atoms brought together as they form a molecule. Lewis structures Resonance considerations
CHEM 511 chapter 2 page 1 of 11 Chapter 2 Molecular Structure and Bonding Read the section on Lewis dot structures, we will not cover this in class. If you have problems, seek out a general chemistry text.
More informationAndrew Rosen *Note: If you can rotate a molecule to have one isomer equal to another, they are both the same
*Note: If you can rotate a molecule to have one isomer equal to another, they are both the same *Note: For hybridization, if an SP 2 is made, there is one unhybridized p orbital (because p usually has
More informationThe symmetry properties & relative energies of atomic orbitals determine how they react to form molecular orbitals. These molecular orbitals are then
1 The symmetry properties & relative energies of atomic orbitals determine how they react to form molecular orbitals. These molecular orbitals are then filled with the available electrons according to
More information11/29/2014. Problems with Valence Bond Theory. VB theory predicts many properties better than Lewis Theory
Problems with Valence Bond Theory VB theory predicts many properties better than Lewis Theory bonding schemes, bond strengths, bond lengths, bond rigidity however, there are still many properties of molecules
More informationChapter 9. Molecular Geometry and Bonding Theories
Chapter 9. Molecular Geometry and Bonding Theories 9.1 Molecular Shapes Lewis structures give atomic connectivity: they tell us which atoms are physically connected to which atoms. The shape of a molecule
More informationChapter 9. Molecular Geometry and Bonding Theories
Chapter 9. Molecular Geometry and Bonding Theories PART I Molecular Shapes Lewis structures give atomic connectivity: they tell us which atoms are physically connected to which atoms. The shape of a molecule
More informationBonding and Physical Properties The Molecular Orbital Theory
Bonding and Physical Properties The Molecular Orbital Theory Ø Developed by F. Hund and R. S. Mulliken in 1932 Ø Diagram of molecular energy levels Ø Magnetic and spectral properties Paramagnetic vs. Diamagnetic
More informationMolecular Orbital Theory
Molecular Orbital Theory Paramagnetic properties of O 2 pranjoto utomo Covalent Bonding Theory Valence Bond Theory useful for deriving shapes/polarity simple but inaccurate/deficient Molecular Orbital
More informationMolecular Orbital Theory
Molecular Orbital Theory 1. MO theory suggests that atomic orbitals of different atoms combine to create MOLECULAR ORBITALS 2. Electrons in these MOLECULAR ORBITALS belong to the molecule as whole 3. This
More informationCHEMISTRY. Chapter 8 ADVANCED THEORIES OF COVALENT BONDING Kevin Kolack, Ph.D. The Cooper Union HW problems: 6, 7, 12, 21, 27, 29, 41, 47, 49
CHEMISTRY Chapter 8 ADVANCED THEORIES OF COVALENT BONDING Kevin Kolack, Ph.D. The Cooper Union HW problems: 6, 7, 12, 21, 27, 29, 41, 47, 49 2 CH. 8 OUTLINE 8.1 Valence Bond Theory 8.2 Hybrid Atomic Orbitals
More informationMolecular Orbitals. Based on Inorganic Chemistry, Miessler and Tarr, 4 th edition, 2011, Pearson Prentice Hall
Molecular Orbitals Based on Inorganic Chemistry, Miessler and Tarr, 4 th edition, 2011, Pearson Prentice Hall Images from Miessler and Tarr Inorganic Chemistry 2011 obtained from Pearson Education, Inc.
More informationChapter 5. Molecular Orbitals
Chapter 5. Molecular Orbitals MO from s, p, d, orbitals: - Fig.5.1, 5.2, 5.3 Homonuclear diatomic molecules: - Fig. 5.7 - Para- vs. Diamagnetic Heteronuclear diatomic molecules: - Fig. 5.14 - ex. CO Hybrid
More informationCovalent Bonding: Orbitals
Hybridization and the Localized Electron Model Covalent Bonding: Orbitals A. Hybridization 1. The mixing of two or more atomic orbitals of similar energies on the same atom to produce new orbitals of equal
More informationIn this lecture we will understand how the molecular orbitals are formed from the interaction of atomic orbitals.
Lecture 7 Title: Understanding of Molecular Orbital Page-1 In this lecture we will understand how the molecular orbitals are formed from the interaction of atomic orbitals. We will see how the electrons
More informationMOLECULAR ORBITAL THEORY Chapter 10.8, Morrison and Boyd
MOLECULAR ORBITAL THEORY Chapter 10.8, Morrison and Boyd more understanding: why oxygen is paramagnetic, why H2 + exists; explanation of excited electronic states (e.g., visible spectra) eliminates need
More informationBe H. Delocalized Bonding. Localized Bonding. σ 2. σ 1. Two (sp-1s) Be-H σ bonds. The two σ bonding MO s in BeH 2. MO diagram for BeH 2
The Delocalized Approach to Bonding: The localized models for bonding we have examined (Lewis and VBT) assume that all electrons are restricted to specific bonds between atoms or in lone pairs. In contrast,
More informationChapter 18 Molecular orbitals and spectroscopy Conjugation of bonds and resonance structures
Chapter 18 Molecular orbitals and spectroscopy 18.1 Diatomic molecules 18.2 Polyatomic molecules 18.3 Conjugation of bonds and resonance structures 18.4 The interaction of light and matter (spectroscopy)
More informationChapter 10: Chemical Bonding II. Bonding Theories
Chapter 10: Chemical Bonding II Dr. Chris Kozak Memorial University of Newfoundland, Canada Bonding Theories Previously, we saw how the shapes of molecules can be predicted from the orientation of electron
More informationANNOUNCEMENTS. If you have questions about your exam 2 grade, write to me or Chapter 8 homework due April. 13 th.
ANNOUNCEMENTS If you have questions about your exam 2 grade, write to me or Chem200@mail.sdsu.edu. Chapter 8 homework due April. 13 th. Chapter 9 home work due April. 20th. Exam 3 is 4/14 at 2 pm. LECTURE
More informationChemical Bonding. Lewis Theory-VSEPR Valence Bond Theory Molecular Orbital Theory
Chemical Bonding Lewis Theory-VSEPR Valence Bond Theory Molecular Orbital Theory Problems with Valence Bond Theory VB theory predicts properties better than Lewis theory bonding schemes, bond strengths,
More informationMOLECULAR STRUCTURE. Molecular Structure - B. Molecular Structure - B. Molecular Structure - B. Molecular Structure - B. Molecular Structure - B
MOLECULAR STRUCTURE Molecular Orbital all orbitals of the appropriate symmetry contribute to a molecular orbital. Bundet Boekfa Chem Div, Faculty Lib Arts & Sci Kasetsart University Kamphaeng Saen Campus
More informationBe H. Delocalized Bonding. Localized Bonding. σ 2. σ 1. Two (sp-1s) Be-H σ bonds. The two σ bonding MO s in BeH 2. MO diagram for BeH 2
The Delocalized Approach to Bonding: The localized models for bonding we have examined (Lewis and VBT) assume that all electrons are restricted to specific bonds between atoms or in lone pairs. In contrast,
More informationChapter 9 Molecular Geometry and Bonding Theories
Lecture Presentation Chapter 9 Geometry James F. Kirby Quinnipiac University Hamden, CT Shapes Lewis Structures show bonding and lone pairs, but do not denote shape. However, we use Lewis Structures to
More information4 Diatomic molecules
s manual for Burrows et.al. Chemistry 3 Third edition 4 Diatomic molecules Answers to worked examples WE 4.1 The Lewis model (on p. 174 in Chemistry 3 ) Use the Lewis model to describe the bonding in (a)
More informationLecture B6 Molecular Orbital Theory. Sometimes it's good to be alone.
Lecture B6 Molecular Orbital Theory Sometimes it's good to be alone. Covalent Bond Theories 1. VSEPR (valence shell electron pair repulsion model). A set of empirical rules for predicting a molecular geometry
More informationReview Outline Chemistry 1B, Fall 2012
Review Outline Chemistry 1B, Fall 2012 -------------------------------------- Chapter 12 -------------------------------------- I. Experiments and findings related to origin of quantum mechanics A. Planck:
More informationChemistry 1B, Fall 2012 Lectures 15-16
Chemistry 1B Fall 2012 Quantum Mechanics of the Covalent Bond for chapter 14 animations and links see: http://switkes.chemistry.ucsc.edu/teaching/chem1b/www_other_links/ch14_links.htm 1 LISTEN UP!!! WE
More informationQUANTUM MECHANICS AND MOLECULAR STRUCTURE
6 QUANTUM MECHANICS AND MOLECULAR STRUCTURE 6.1 Quantum Picture of the Chemical Bond 6.2 Exact Molecular Orbital for the Simplest Molecule: H + 2 6.3 Molecular Orbital Theory and the Linear Combination
More informationChapter 9. Covalent Bonding: Orbitals
Chapter 9. Covalent onding: Orbitals Models to explain the structures and/or energies of the covalent molecules Localized Electron (LE) onding Model Lewis Structure Valence Shell Electron Pair Repulsion
More informationTentative content material to be covered for Exam 2 (Wednesday, November 2, 2005)
Tentative content material to be covered for Exam 2 (Wednesday, November 2, 2005) Chapter 16 Quantum Mechanics and the Hydrogen Atom 16.1 Waves and Light 16.2 Paradoxes in Classical Physics 16.3 Planck,
More informationChapter 9: Molecular Geometries and Bonding Theories Learning Outcomes: Predict the three-dimensional shapes of molecules using the VSEPR model.
Chapter 9: Molecular Geometries and Bonding Theories Learning Outcomes: Predict the three-dimensional shapes of molecules using the VSEPR model. Determine whether a molecule is polar or nonpolar based
More informationMolecular Geometry and Bonding Theories. Chapter 9
Molecular Geometry and Bonding Theories Chapter 9 Molecular Shapes CCl 4 Lewis structures give atomic connectivity; The shape of a molecule is determined by its bond angles VSEPR Model Valence Shell Electron
More informationChapter 10. VSEPR Model: Geometries
Chapter 10 Molecular Geometry VSEPR Model: Geometries Valence Shell Electron Pair Repulsion Theory Electron pairs repel and get as far apart as possible Example: Water Four electron pairs Farthest apart
More informationNH 3 H 2 O N 2. Why do they make chemical bonds? Molecular Orbitals
N 2 NH 3 H 2 O Why do they make chemical bonds? 5 Molecular Orbitals Why do they make chemical bonds? Stabilization Bond energy Types of Chemical Bonds Metallic Bond Ionic Bond Covalent Bond Covalent Bond
More informationMolecular Orbital Theory This means that the coefficients in the MO will not be the same!
Diatomic molecules: Heteronuclear molecules In heteronuclear diatomic molecules, the relative contribution of atomic orbitals to each MO is not equal. Some MO s will have more contribution from AO s on
More informationChemistry: The Central Science. Chapter 9: Molecular Geometry and Bonding Theory
Chemistry: The Central Science Chapter 9: Molecular Geometry and Bonding Theory The shape and size of a molecule of a particular substance, together with the strength and polarity of its bonds, largely
More informationTopic 2. Structure and Bonding Models of Covalent Compounds of p-block Elements
Topic 2 2-1 Structure and Bonding Models of Covalent Compounds of p-block Elements Bonding 2-2 Many different approaches to describe bonding: Ionic Bonding: Elements with large electronegativity differences;
More informationShapes of Molecules. Lewis structures are useful but don t allow prediction of the shape of a molecule.
Shapes of Molecules Lewis structures are useful but don t allow prediction of the shape of a molecule. H O H H O H Can use a simple theory based on electron repulsion to predict structure (for non-transition
More informationChemistry 1B, Fall 2013 Lectures 15-16
Chemistry 1, Fall 2013 Lectures 1516 Chemistry 1 Fall 2013 Lectures 1516 Quantum Mechanics of the Covalent ond LISTEN UP!!! WE WILL E COVERING SECOND PRT OF CHPTER 14 (pp 676688) FIRST You will go CRZY
More informationMolecular shape is only discussed when there are three or more atoms connected (diatomic shape is obvious).
Chapter 10 Molecular Geometry (Ch9 Jespersen, Ch10 Chang) The arrangement of the atoms of a molecule in space is the molecular geometry. This is what gives the molecules their shape. Molecular shape is
More informationMolecular structure and bonding
Chemistry 481(01) Spring 2017 Instructor: Dr. Upali Siriwardane e-mail: upali@latech.edu Office: CTH 311 Phone 257-4941 Office Hours: M,W 8:00-9:00 & 11:00-12:00 am; Tu,Th, F 9:30-11:30 a.m. April 4, 2017:
More informationChapter 10 Theories of Covalent Bonding
Chapter 10 Theories of Covalent Bonding 1 Atomic Orbitals Molecules Bonding and 2 Molecular Structure Questions How are molecules held together? Why is O 2 paramagnetic? And how is this property connected
More informationMolecular Orbital Theory. WX AP Chemistry Chapter 9 Adapted from: Luis Bonilla Abel Perez University of Texas at El Paso
Molecular Orbital Theory WX AP Chemistry Chapter 9 Adapted from: Luis Bonilla Abel Perez University of Texas at El Paso Molecular Orbital Theory The goal of molecular orbital theory is to describe molecules
More informationWhat Do Molecules Look Like?
What Do Molecules Look Like? The Lewis Dot Structure approach provides some insight into molecular structure in terms of bonding, but what about 3D geometry? Recall that we have two types of electron pairs:
More informationGeneral Physical Chemistry II
General Physical Chemistry II Lecture 10 Aleksey Kocherzhenko October 7, 2014" Last time " promotion" Promotion and hybridization" [He] 2s 2 2p x 1 2p y 1 2p z0 " 2 unpaired electrons" [He] 2s 1 2p x 1
More informationChapter 10. VSEPR Model: Geometries
Chapter 10 Molecular Geometry VSEPR Model: Geometries Valence Shell Electron Pair Repulsion Theory Electron pairs repel and get as far apart as possible Example: Water Four electron pairs Two bonds Two
More informationGHW#3 Louisiana Tech University, Chemistry 281. POGIL exercise on Chapter 2. Covalent Bonding: VSEPR, VB and MO Theories. How and Why?
GHW#3 Louisiana Tech University, Chemistry 281. POGIL exercise on Chapter 2. Covalent Bonding: VSEPR, VB and MO Theories. How and Why? How is Valence Shell Electron Pair Repulsion Theory developed from
More informationMolecular Bond Theory
Molecular Bond Theory Short comings of the localized electron model: electrons are not really localized so the concept of resonance was added no direct information about bond energies Molecular Orbital
More informationHomework 08 - Bonding Theories & IMF
HW08 - Bonding Theories & IMF This is a preview of the published version of the quiz Started: Jun 4 at 11:4am Quiz Instructions Homework 08 - Bonding Theories & IMF Question 1 A sigma bond... stems from
More information5.111 Lecture Summary #13 Monday, October 6, 2014
5.111 Lecture Summary #13 Monday, October 6, 2014 Readings for today: Section 3.8 3.11 Molecular Orbital Theory (Same in 5 th and 4 th ed.) Read for Lecture #14: Sections 3.4, 3.5, 3.6 and 3.7 Valence
More informationLesmahagow High School CfE Advanced Higher Chemistry. Unit 2 Organic Chemistry and Instrumental Analysis. Molecular Orbitals and Structure
Lesmahagow High School CfE Advanced Higher Chemistry Unit 2 Organic Chemistry and Instrumental Analysis Molecular Orbitals and Structure 1 Molecular Orbitals Orbitals can be used to explain the bonding
More informationDrawing Lewis Structures
Chapter 2 - Basic Concepts: molecules Bonding models: Valence-Bond Theory (VB) and Molecular Orbital Theory (MO) Lewis acids and bases When both of the electrons in the covalent bond formed by a Lewis
More informationChapter 12: Chemical Bonding II: Additional Aspects
General Chemistry Principles and Modern Applications Petrucci Harwood Herring 8 th Edition Chapter 12: Chemical Bonding II: Additional Aspects Philip Dutton University of Windsor, Canada N9B 3P4 Prentice-Hall
More informationGeneral Chemistry. Contents. Chapter 12: Chemical Bonding II: Additional Aspects What a Bonding Theory Should Do. Potential Energy Diagram
General Chemistry Principles and Modern Applications Petrucci Harwood Herring 8 th Edition Chapter 12: Chemical Bonding II: Additional Aspects Philip Dutton University of Windsor, Canada N9B 3P4 Contents
More information1 r A. r B. 2m e. The potential energy of the electron is. r A and r B are the electron s distances from the nuclei A and B. This expression can be
Introduction to Molecular Structure The Born-Oppenheimer approximation The Born-Oppenheimer approximation supposes that the nuclei, being so much heavier than the electron, move relatively slow and may
More informationPage III-8-1 / Chapter Eight Lecture Notes MAR. Two s orbitals overlap. One s & one p. overlap. Two p orbitals. overlap MAR
Bonding and Molecular Structure: Orbital ybridization and Molecular Orbitals Chapter 8 Page III-8-1 / Chapter Eight Lecture Notes Advanced Theories of Chemical Bonding Chemistry 222 Professor Michael Russell
More informationChapter 9. Covalent Bonding: Orbitals
Chapter 9 Covalent Bonding: Orbitals EXERCISE! Draw the Lewis structure for methane, CH 4. What is the shape of a methane molecule? tetrahedral What are the bond angles? 109.5 o H H C H H Copyright Cengage
More informationANNOUNCEMENTS. If you have questions about your exam 2 grade, write to me or Chapter 7 homework due Nov, 9 th.
ANNOUNCEMENTS If you have questions about your exam 2 grade, write to me or Chem200@sdsu.edu. Chapter 7 homework due Nov, 9 th. Chapter 8 homework due Nov. 16 th. Exam 3 is 11/17 at 2 pm. LECTURE OBJECTIVES
More informationChapter 9. Chemical Bonding II: Molecular Geometry and Bonding Theories
Chapter 9 Chemical Bonding II: Molecular Geometry and Bonding Theories Topics Molecular Geometry Molecular Geometry and Polarity Valence Bond Theory Hybridization of Atomic Orbitals Hybridization in Molecules
More informationChapter 3. Orbitals and Bonding
Chapter 3. Orbitals and Bonding What to master Assigning Electrons to Atomic Orbitals Constructing Bonding and Antibonding Molecular Orbitals with Simple MO Theory Understanding Sigma and Pi Bonds Identifying
More informationUNIT TWO BOOKLET 1. Molecular Orbitals and Hybridisation
DUNCANRIG SECONDARY ADVANCED HIGHER CHEMISTRY UNIT TWO BOOKLET 1 Molecular Orbitals and Hybridisation In the inorganic unit we learned about atomic orbitals and how they could be used to write the electron
More informationCh. 9- Molecular Geometry and Bonding Theories
Ch. 9- Molecular Geometry and Bonding Theories 9.0 Introduction A. Lewis structures do not show one of the most important aspects of molecules- their overall shapes B. The shape and size of molecules-
More informationChapter 10. Structure Determines Properties! Molecular Geometry. Chemical Bonding II
Chapter 10 Chemical Bonding II Structure Determines Properties! Properties of molecular substances depend on the structure of the molecule The structure includes many factors, including: the skeletal arrangement
More informationChemistry 6 (9 am section) Spring Covalent Bonding
Chemistry 6 (9 am section) Spring 000 Covalent Bonding The stability of the bond in molecules such as H, O, N and F is associated with a sharing (equal) of the VALENCE ELECTRONS between the BONDED ATOMS.
More informationUNIT III Chemical Bonding There are two basic approaches to chemical bonding based on the results of quantum mechanics. These are the Valence Bond
UNIT III Chemical Bonding There are two basic approaches to chemical bonding based on the results of quantum mechanics. These are the Valence Bond Theory (VB) and the Molecular Orbital theory (MO). 1)
More informationChapter 9 Molecular Geometry and Bonding Theories
Chapter 9 Molecular Geometry and Bonding Theories 9.1 Molecular Shapes Lewis structures give atomic connectivity (which atoms are physically connected). By noting the number of bonding and nonbonding electron
More informationLecture 9 Electronic Spectroscopy
Lecture 9 Electronic Spectroscopy Molecular Orbital Theory: A Review - LCAO approximaton & AO overlap - Variation Principle & Secular Determinant - Homonuclear Diatomic MOs - Energy Levels, Bond Order
More informationCB VII. Molecular Orbital (MO) Theory. General. Basic Principles. Basic Ideas. further improvement on Lewis, VSEPR & VB theory;
chem101/3, D1 fa010 po 14 1 CB VII Molecular Orbital (MO) Theory chem101/3, D1 fa010 po 14 General further improvement on Lewis, VSEPR & VB theory; resulting in better info on: bond energy bond order magnetic
More informationChapter 9. Covalent Bonding: Orbitals. Copyright 2017 Cengage Learning. All Rights Reserved.
Chapter 9 Covalent Bonding: Orbitals Chapter 9 Table of Contents (9.1) (9.2) (9.3) (9.4) (9.5) (9.6) Hybridization and the localized electron model The molecular orbital model Bonding in homonuclear diatomic
More informationChapter 10 Chemical Bonding II
Chapter 10 Chemical Bonding II Valence Bond Theory Valence Bond Theory: A quantum mechanical model which shows how electron pairs are shared in a covalent bond. Bond forms between two atoms when the following
More informationChapter 10: Chemical Bonding II: Molecular Shapes; VSEPR, Valence Bond and Molecular Orbital Theories
C h e m i s t r y 1 A : C h a p t e r 1 0 P a g e 1 Chapter 10: Chemical Bonding II: Molecular Shapes; VSEPR, Valence Bond and Molecular Orbital Theories Homework: Read Chapter 10: Work out sample/practice
More informationMO theory is better for spectroscopy (Exited State Properties; Ionization)
CHEM 2060 Lecture 25: MO Theory L25-1 Molecular Orbital Theory (MO theory) VB theory treats bonds as electron pairs. o There is a real emphasis on this point (over-emphasis actually). VB theory is very
More informationContents. 1. Basic Concepts. 2. The Covalent Bond. 3. The Valence-Shell Electron-Pair Repulsion Models 4. Bond theories. 5. The Metallic Bond.
Chemical Bonding (II) Topic 4. Chemical Bonding (II) (II) 1 Contents 1. Basic Concepts. a) Molecular parameters b) Lewis Dot Symbols 2. The Covalent Bond a) Polar Covalent Bond b) Formal Charge c) Exceptions
More informationHybridization and Molecular Orbital (MO) Theory
ybridization and Molecular Orbital (MO) Theory Chapter 10 istorical Models G.N.Lewis and I. Langmuir (~1920) laid out foundations Ionic species were formed by electron transfer Covalent molecules arise
More informationEXAM II Material. Part I Chemical Bonding I Lewis Theory Chapter 9 pages A. Drawing electron dot structures HOW TO:
CHEMISTRY 112 LECTURE EXAM II Material Part I Chemical Bonding I Lewis Theory Chapter 9 pages 376-386 A. Drawing electron dot structures HOW TO: 1. Write e- dot structure for the individual atoms. 2. a)
More informationPHYSICAL CHEMISTRY I. Chemical Bonds
PHYSICAL CHEMISTRY I Chemical Bonds Review The QM description of bonds is quite good Capable of correctly calculating bond energies and reaction enthalpies However it is quite complicated and sometime
More informationMolecular-Orbital Theory
Prof. Dr. I. Nasser atomic and molecular physics -551 (T-11) April 18, 01 Molecular-Orbital Theory You have to explain the following statements: 1- Helium is monatomic gas. - Oxygen molecule has a permanent
More informationChemistry 2000 Lecture 1: Introduction to the molecular orbital theory
Chemistry 2000 Lecture 1: Introduction to the molecular orbital theory Marc R. Roussel January 5, 2018 Marc R. Roussel Introduction to molecular orbitals January 5, 2018 1 / 24 Review: quantum mechanics
More information5.111 Principles of Chemical Science
MIT OpenCourseWare http://ocw.mit.edu 5.111 Principles of Chemical Science Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 5.111 Lecture Summary
More informationTYPES OF SYMMETRIES OF MO s s-s combinations of orbitals: , if they are antibonding. s-p combinatinos of orbitals: CHEMICAL BONDING.
TYPES OF SYMMETRIES OF MO s s-s combinations of : Orbitals Molecular Orbitals s s Node s s (g) (g) Bonding orbital Antibonding orbital (u) 4 (u) s-s combinations of atomic In the bonding MO there is increased
More informationChapter 9. Covalent Bonding: Orbitals
Chapter 9 Covalent Bonding: Orbitals Chapter 9 Table of Contents 9.1 Hybridization and the Localized Electron Model 9.2 The Molecular Orbital Model 9.3 Bonding in Homonuclear Diatomic Molecules 9.4 Bonding
More informationChemistry 2000 Lecture 2: LCAO-MO theory for homonuclear diatomic molecules
Chemistry 2000 Lecture 2: LCAO-MO theory for homonuclear diatomic molecules Marc R. Roussel January 5, 2018 Marc R. Roussel Homonuclear diatomics January 5, 2018 1 / 17 MO theory for homonuclear diatomic
More informationELEMENTARY BAND THEORY
ELEMENTARY BAND THEORY PHYSICIST Solid state band Valence band, VB Conduction band, CB Fermi energy, E F Bloch orbital, delocalized n-doping p-doping Band gap, E g Direct band gap Indirect band gap Phonon
More informationOrganic Electronic Devices
Organic Electronic Devices Week 2: Electronic Structure Lecture 2.1: Atomic and Molecular Orbitals Bryan W. Boudouris Chemical Engineering Purdue University 1 Lecture Overview and Learning Objectives Concepts
More informationCHEMISTRY 112 LECTURE EXAM II Material
CHEMISTRY 112 LECTURE EXAM II Material Part I Chemical Bonding I Lewis Theory Chapter 9 pages 376-386 A. Drawing electron dot structures HOW TO: 1. Write e- dot structure for the individual atoms. 2. a)
More informationUnit3Day4-LaBrake. Important Information. Is the molecule CH 2 Cl 2? Vanden Bout/LaBrake/Crawford CH301
Unit3Day4-LaBrake Page 1 Unit3Day4-LaBrake Monday, October 21, 2013 11:32 AM Vanden Bout/LaBrake/Crawford CH301 WHY DOES A FROG FLOAT IN A MAGNETIC FIELS? MORE ON BONDING THEORIES UNIT 3 Day 4 Important
More informationChapter 9 practice questions
Class: Date: Chapter 9 practice questions Multiple Choice Identify the choice that best completes the statement or answers the question. 1. All of the following statements concerning valence bond (VB)
More informationMolecular Orbital Approach to Bonding
Molecular Orbital Approach to Bonding Chemistry 362; spring 2019 Marcetta Y. Darensbourg, Professor Xuemei Yang, Graduate Assistant Kyle Burns, Graduate Assistant The following slides were modified from
More informationMolecular shape is determined by the number of bonds that form around individual atoms.
Chapter 9 CH 180 Major Concepts: Molecular shape is determined by the number of bonds that form around individual atoms. Sublevels (s, p, d, & f) of separate atoms may overlap and result in hybrid orbitals
More informationLecture 14 Chemistry 362 M. Darensbourg 2017 Spring term. Molecular orbitals for diatomics
Lecture 14 Chemistry 362 M. Darensbourg 2017 Spring term Molecular orbitals for diatomics Molecular Orbital Theory of the Chemical Bond Simplest example - H 2 : two H atoms H A and H B Only two a.o.'s
More informationChapter 9 - Covalent Bonding: Orbitals
Chapter 9 - Covalent Bonding: Orbitals 9.1 Hybridization and the Localized Electron Model A. Hybridization 1. The mixing of two or more atomic orbitals of similar energies on the same atom to produce new
More informationChemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals
Chemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 10 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Valence shell electron
More informationMolecular Geometry. Dr. Williamson s Molecular Geometry Notes. VSEPR: Definition of Terms. Dr. V.M. Williamson Texas A & M University Student Version
Molecular Geometry Dr. V.M. Williamson Texas A & M University Student Version Valence Shell Electron Pair Repulsion- VSEPR 1. Valence e- to some extent 2. Electron pairs move as far away as possible to
More informationMolecular Geometry. Dr. Williamson s Molecular Geometry Notes. VSEPR: Definition of Terms. VSEPR: Electronic Geometries VSEPR
Molecular Geometry Dr. V.M. Williamson Texas A & M University Student Version Valence Shell Electron Pair Repulsion- VSEPR 1. Valence e- to some extent 2. Electron pairs move as far away as possible to
More informationCHEM J-5 June 2014
CHEM1101 2014-J-5 June 2014 The molecular orbital energy level diagrams for H 2, H 2 +, H 2 and O 2 are shown below. Fill in the valence electrons for each species in its ground state and label the types
More informationMO theory considers the entire molecule at once not isolated electron pairs.
5. Molecular Orbital Theory READING: Chapter 2, Sections 2.7 2.10 MO theory considers the entire molecule at once not isolated electron pairs. Consequence: An electron pair can be bonding/non-bonding/anti-bonding
More informationChapter 4. Molecular Structure and Orbitals
Chapter 4 Molecular Structure and Orbitals Chapter 4 Table of Contents (4.1) (4.2) (4.3) (4.4) (4.5) (4.6) (4.7) Molecular structure: The VSEPR model Bond polarity and dipole moments Hybridization and
More information