Coordination Chemistry: Bonding Theories. Molecular Orbital Theory. Chapter 20
|
|
- Wendy Shelton
- 5 years ago
- Views:
Transcription
1 Coordination Chemistry: Bonding Theories Molecular Orbital Theory Chapter 20
2 Review of the Previous Lecture 1. Discussed magnetism in coordination chemistry and the different classification of compounds with magnetic properties 2. Evaluated the magnetic susceptibility of compounds as it depends on temperature 3. Described the property of spin crossover 4. Briefly surveyed tools to characterized the magnetic properties of compounds 2
3 1. Introduction to Molecular Orbital Theory Unlike crystal field theory, molecular orbital theory accounts for covalency in M-L bonding Electrons shared by metal ions and ligands The identity of the ligand is important in the sharing of these electrons Let s examine how MOT helps us to account for and π interactions. 3
4 2. The Spectrochemical Series I - < Br - < [NCS] - < Cl - < F - < [OH] - < [ox] 2- ~ H 2 O< [NCS] - < NH 3 < en < [CN] - ~ CO π donors σ donors π acceptors Weak field ligands Small Δ High spin π donors Ligands increasing Δ oct Strong field ligands Large Δ Low spin π acceptors If splitting of the d orbitals resulted simply from the effect of point charges then anionic ligands would exert the greatest effect on the magnitude of Δ. OH - would be expected to induce a stronger field than H 2 O but does not 4
5 3. interactions Let s use the octahedral geometry (C.N. = 6) as our point of reference: z x y Use vectors aligned with the internuclear axes of the 6 M-L bonds as your basis set to examine interactions in coordination compounds. 5
6 3. interactions Use group theory to identify the symmetry of the metal atomic orbitals and the ligand group orbitals that will be involved in bonding. z Have 6 vectors to represent 6 bonds, therefore expect your reducible representation to be composed of 6 irreducible representations Point Group: O h x y red ( )= a 1g + e g + t 1u 6 irreducible representations 6
7 3A. Metal atomic orbitals engaged in interactions z a 1g :sorbital e g :d z 2 ;d x 2-y2 x y t 1u :p x,p y,p z For a 1 st row transition metal, the orbitals would be from the 3d, 4s, and 4p orbitals. Of these, the d xy, d yz, and d xz do not engage in bonding because they are of the t 2g symmetry Nonbonding orbitals 7
8 3B. Ligand group orbitals engaged in interactions z The ligand group orbitals will have the a 1g, e g, t 1u symmetries and there will be a total of six. x y Will be defined by atomic orbitals from the ligands that engage in bonding For instance, if L = hydrogen, then s orbitals if L = H 2 O, then sp 3 hybrid orbitals Let s consider the ligand group orbitals as a set of lobes that will overlap with the metal atomic orbital lobes. 8
9 a 1g Symmetry Metal Atomic Orbital Ligand Group Orbital The a 1g metal atomic orbital and LGO will generate one bonding molecular orbital and one antibonding molecular orbital 9
10 a 1g Symmetry Bonding Molecular Orbital Antibonding Molecular Orbital Zero Nodes One Spherical Node 10
11 t 1u Symmetry Metal Atomic Orbital Ligand Group Orbital The t 1u metal atomic orbitals and LGOs will generate three bonding molecular orbitals and three antibonding molecular orbitals 11
12 t 1u Symmetry Bonding Molecular Orbital Metal Atomic Orbital One Nodal Plane Ligand Group Orbital Antibonding Molecular Orbital Three Nodal Planes 12
13 e g Symmetry Metal Atomic Orbital Ligand Group Orbital The e g metal atomic orbitals and LGOs will generate two bonding molecular orbitals and two antibonding molecular orbitals 13
14 e g Symmetry Bonding Molecular Orbital Metal Atomic Orbital Two Nodal Planes Ligand Group Orbital Antibonding Molecular Orbital Two Nodal Planes, One Nodal Cylinder 14
15 e g Symmetry Bonding Molecular Orbital Metal Atomic Orbital Two Nodal Cylinders Ligand Group Orbital Antibonding Molecular Orbital Three Nodal Cylinders 15
16 3C. Molecular Orbital Diagram for σ interaction The 6 metal atomic orbitals interact with the 6 LGOs : 12 molecular orbitals 6 bonding molecular orbitals 6 antibonding molecular orbitals Antibonding MOs Bonding MOs 16
17 3C. Molecular Orbital Diagram for σ interaction The 6 metal atomic orbitals interact with the 6 LGOs : 12 molecular orbitals 6 bonding molecular orbitals 6 antibonding molecular orbitals Two nodes One node No nodes 17
18 3C. Molecular Orbital Diagram for σ interaction The 6 metal atomic orbitals interact with the 6 LGOs : 12 molecular orbitals 6 bonding molecular orbitals 6 antibonding molecular orbitals The t 2g metal atomic orbitals are nonbonding d xy,d yz,andd xz orbitals 18
19 3C. Molecular Orbital Diagram for σ interaction Each of the 6 ligands contributes 2 electrons for a total of 12 electrons: The 12 ligand electrons fill the bonding molecular orbitals (a 1g, t 1u,e g ) The metal-ligand interactions stabilize the 12 ligand electrons 12 e - 19
20 3C. Molecular Orbital Diagram for σ interaction The 6 LGOs create an octahedral field: oct is defined by the separation in the nonbonding metal atomic orbitals t 2g and the antibonding molecular orbitals e g * The metal d orbital electrons will fill in these orbitals 20
21 3C. Molecular Orbital Diagram for σ interaction * 3d The metal-ligand interactions stabilize the metal d electrons. Recall CFSE. 21
22 3D. The 18 electron rule The most stable metal-ligand interactions in octahedral complexes are those that result in the filling of the metal and ligand electrons into the bonding molecular orbitals and the nonbonding t 2g metal atomic orbitals. Altogether, these 9 orbitals accept 18 electrons 22
23 4. π interactions Consider ligand orbitals that can engage in π interactions with metals: M L M L M L d π p π d π d π d π π * 23
24 The Spectrochemical Series I - < Br - < [NCS] - < Cl - < F - < [OH] - < [ox] 2- ~ H 2 O< [NCS] - < NH 3 < en < [CN] - ~ CO π donors σ donors π acceptors M L d π p π 24
25 4A. Let s consider p ligand orbitals involved in and π interactions with metals Consider each of the ligand p orbitals that can engage in and π interactions with metals: 1 p orbital along the internuclear axis for interactions 2 p orbitals perpendicular to the internuclear axis for π interactions z L L x L L M L L y M M interactions π interactions 25
26 4B. Use group theory to examine the π interactions with metals Choose a basis set to define the symmetry of the ligand group orbitals that can engage in π interactions 12 vectors indicate that the reducible representation will be defined by 12 irreducible representations Point Group: O h red (π) = t 2g + t 2u + t 1u + t 1g z 12 irreducible representations M y M x 26
27 4C. Focus on the t 2g orbital symmetry We will focus on the t 2g orbital symmetry because this symmetry represented the nonbonding metal atomic orbitals in the molecular orbital diagram for only interactions. These orbitals can engage in π interactions. d xy,d yz,andd xz orbitals z M y M x 27
28 4D. Factors to consider regarding the energy of the t 2g ligand group orbitals The energy of the t 2g ligand group orbitals will be greater or lower than the metal atomic orbitals depending on The electronegativity difference between the ligands and the metal Whether the LGOs are electron occupied z M y M x 28
29 4E. Explaining the origins of the weak field ligands Consider the octahedral complex [CoF 6 ] 3- : Co 3+ ;d 6 F - is more electronegative than Co 3+ The t 2g LGOs will be lower in energy than the t 2g metal atomic orbitals When these orbitals interact, they will form 3 bonding molecular orbitals (t 2g ) and 3 antibonding molecular orbitals (t 2g* ) 29
30 4E. Explaining the origins of the weak field ligands Consider the complex [CoF 6 ] 3- : 6F - : Total of 36 electrons in the 18 p orbitals 12 electrons used for interactions The remaining 24 electrons can engage in π interactions, of which 6 of these belong z to the t 2g LGOs M y M x interactions π interactions 30
31 Molecular Orbital Diagram including π interaction with Weak Field Ligands 31
32 Molecular Orbital Diagram including π interaction with Weak Field Ligands 32
33 Molecular Orbital Diagram including π interaction with Weak Field Ligands [CoF 6 ] 3- High spin, S = 2 Co 3+ ; d 6 33
34 4E. Explaining the origins of the strong field ligands I - < Br - < [NCS] - < Cl - < F - < [OH] - < [ox] 2- ~ H 2 O< [NCS] - < NH 3 < en < [CN] - ~ CO π donors σ donors π acceptors M L Consider the octahedral complex [Co(CO) 6 ] 3+ : Co 3+ ;d 6 d π π * 34
35 Molecular Orbital Diagram for CO LUMO t 2g symmetry The t 2g LGOs are higher in energy than the t 2g metal atomic orbitals These orbitals are unoccupied and can accept electrons from the metal 35
36 Molecular Orbital Diagram including π interaction with Strong Field Ligands 36
37 Molecular Orbital Diagram including π interaction with Strong Field Ligands 37
38 Molecular Orbital Diagram including π interaction with Strong Field Ligands [Co(CO) 6 ] 3+ Co 3+ ; d 6 Low spin, S = 0 38
39 4F. Revisiting the 18 electron rule The most stable metalligand interactions in octahedral complexes are those that result in the filling of the metal and ligand electrons into the 9 bonding molecular orbitals Altogether, these 9 orbitals accept 18 electrons 39
40 4G. π backbonding with π acceptor ligands M d π π * The ligand donates electron density to the metal through bonds The metal donates electron density to the ligand through π bonds 40
41 4G. π backbonding with π acceptor ligands π backbonding weakens the CO bond because electron density is moved into its π * molecular orbital: Ths effect is more pronounced depending on the electron donation capacity of another ligand positioned trans to the CO ligand Electron withdrawing Strengthens CO bond; Increased υ CO Trans influence trans-l M Electron donating d π π * Weakens CO bond; Decreased υ CO 41
Molecular Orbital Theory (MOT)
Molecular Orbital Theory (MOT) In this section, There are another approach to the bonding in metal complexes: the use of molecular orbital theory (MOT). In contrast to crystal field theory, the molecular
More informationCoordination Chemistry: Bonding Theories. Crystal Field Theory. Chapter 20
Coordination Chemistry: Bonding Theories Crystal Field Theory Chapter 0 Review of the Previous Lecture 1. We discussed different types of isomerism in coordination chemistry Structural or constitutional
More informationElectronic structure Crystal-field theory Ligand-field theory. Electronic-spectra electronic spectra of atoms
Chapter 19 d-metal complexes: electronic structure and spectra Electronic structure 19.1 Crystal-field theory 19.2 Ligand-field theory Electronic-spectra 19.3 electronic spectra of atoms 19.4 electronic
More information- an approach to bonding that is useful for making estimates of E of orbitals in coordination complexes
10.4 Angular Overlap - an approach to bonding that is useful for making estimates of E of orbitals in coordination complexes - estimate the strength of interaction b/w ligand orbitals & metal d orbitals
More informationRDCH 702 Lecture 4: Orbitals and energetics
RDCH 702 Lecture 4: Orbitals and energetics Molecular symmetry Bonding and structure Molecular orbital theory Crystal field theory Ligand field theory Provide fundamental understanding of chemistry dictating
More informationElectronic structure / bonding in d-block complexes
LN05-1 Electronic structure / bonding in d-block complexes Many, many properties of transition metal complexes (coordination number, structure, colour, magnetism, reactivity) are very sensitive to the
More informationChemistry 3211 Coordination Chemistry Part 3 Ligand Field and Molecular Orbital Theory
Chemistry 3211 Coordination Chemistry Part 3 Ligand Field and Molecular Orbital Theory Electronic Structure of Six and Four-Coordinate Complexes Using Crystal Field Theory, we can generate energy level
More informationOrbitals and energetics
Orbitals and energetics Bonding and structure Molecular orbital theory Crystal field theory Ligand field theory Provide fundamental understanding of chemistry dictating radionuclide complexes Structure
More informationCrystal Field Theory
Crystal Field Theory It is not a bonding theory Method of explaining some physical properties that occur in transition metal complexes. Involves a simple electrostatic argument which can yield reasonable
More informationPAPER No. 7: Inorganic chemistry II MODULE No. 5: Molecular Orbital Theory
Subject Chemistry Paper No and Title Module No and Title Module Tag 7, Inorganic chemistry II 5, Molecular Orbital Theory CHE_P7_M5 TABLE OF CONTENTS 1. Learning Outcomes 2. Introduction to Ligand Field
More informationChemistry Instrumental Analysis Lecture 11. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 11 Molar Absorptivities Range 0 to 10 5 Magnitude of e depends on capture cross section of the species and probability of the energy-absorbing transition. e
More informationInorganic Chemistry with Doc M. Day 18. Transition Metals Complexes IV: Ligand Field Theory continued
Inorganic Chemistry with Doc M. Day 18. Transition Metals Complexes IV: Ligand Field Theory continued Topics: 1. The three scenarios 2. Scenario 3: π-back bonding 1. The three scenarios for the MO energy
More informationCrystal Field Theory History
Crystal Field Theory History 1929 Hans Bethe - Crystal Field Theory (CFT) Developed to interpret color, spectra, magnetism in crystals 1932 J. H. Van Vleck - CFT of Transition Metal Complexes Champions
More informationCoordination Chemistry II: Bonding
d x2-y2 b 1g e g d x2-y2 b 1g D 1 t 2 d xy, d yz, d zx D t d d z2, d x2-y2 D o d z2 a 1g d xy D 2 d z2 b 2g a 1g e d z2, d x2-y2 d xy, d yz, d zx d xy b 2g D 3 t 2g e g d yz, d zx e g d yz, d zx 10 Coordination
More informationCrystal Field Theory
6/4/011 Crystal Field Theory It is not a bonding theory Method of explaining some physical properties that occur in transition metal complexes. Involves a simple electrostatic argument which can yield
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 informationChemistry 1000 Lecture 26: Crystal field theory
Chemistry 1000 Lecture 26: Crystal field theory Marc R. Roussel November 6, 18 Marc R. Roussel Crystal field theory November 6, 18 1 / 18 Crystal field theory The d orbitals z 24 z 16 10 12 8 0 0 10 10
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 information5.04 Principles of Inorganic Chemistry II
MIT OpenCourseWare http://ocw.mit.edu 5.04 Principles of Inorganic Chemistry II Fall 008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 5.04, Principles
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 informationPAPER No.7 : Inorganic Chemistry-II MODULE No.1 : Crystal Field Theory
Subject Chemistry Paper No and Title Module No and Title Module Tag 7, Inorganic Chemistry II 1, Crystal Field Theory CHE_P7_M1 TABLE OF CONTENTS 1. Learning Outcomes 2. Introduction to Crystal Field Theory
More informationChapter 9. Molecular Geometries and Bonding Theories. Lecture Presentation. John D. Bookstaver St. Charles Community College Cottleville, MO
Lecture Presentation Chapter 9 Theories John D. Bookstaver St. Charles Community College Cottleville, MO Shapes The shape of a molecule plays an important role in its reactivity. By noting the number of
More informationChapter 25 Transition Metals and Coordination Compounds Part 2
Chapter 25 Transition Metals and Coordination Compounds Part 2 Bonding in Coordination Compounds Valence Bond Theory Coordinate covalent bond is between: completely filled atomic orbital and an empty atomic
More informationConstructing a MO of NH 3. Nitrogen AO symmetries are
Constructing a MO of NH 3 Nitrogen AO symmetries are To develop a MO scheme for NH 3 assume that only the 2s and2p orbitals of nitrogen interact with the hydrogen 1s orbitals (i.e., the nitrogen 1s orbital
More informationBonding in Coordination Compounds. Crystal Field Theory. Bonding in Transition Metal Complexes
Bonding in Transition Metal Complexes 1) Crystal Field Theory (ligand field theory) Crystal Field Theory Treat igands as negative charges (they repel the e- in the d orbitals deals only with d orbitals
More informationHow to identify types of transition in experimental spectra
17 18 19 How to identify types of transition in experimental spectra 1. intensity 2. Band width 3. polarization Intensities are governed by how well the selection rules can be applied to the molecule under
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 informationChemistry 201: General Chemistry II - Lecture
Chemistry 201: General Chemistry II - Lecture Dr. Namphol Sinkaset Chapter 23 Study Guide Concepts 1. In the transition metals, the ns orbital fills before the (n-1)d orbitals. However, the ns orbital
More informationMolecular Orbital Theory and Charge Transfer Excitations
Molecular Orbital Theory and Charge Transfer Excitations Chemistry 123 Spring 2008 Dr. Woodward Molecular Orbital Diagram H 2 Antibonding Molecular Orbital (Orbitals interfere destructively) H 1s Orbital
More informationA Rigorous Introduction to Molecular Orbital Theory and its Applications in Chemistry. Zachary Chin, Alex Li, Alex Liu
A Rigorous Introduction to Molecular Orbital Theory and its Applications in Chemistry Zachary Chin, Alex Li, Alex Liu Quantum Mechanics Atomic Orbitals and Early Bonding Theory Quantum Numbers n: principal
More informationChapter 21 d-block metal chemistry: coordination complexes
Chapter 21 d-block metal chemistry: coordination complexes Bonding: valence bond, crystal field theory, MO Spectrochemical series Crystal field stabilization energy (CFSE) Electronic Spectra Magnetic Properties
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 informationChemical bonding in complexes of transition metals
Chemical bonding in complexes of transition metals Chem 202, Sept. 28, 2010 What are transition elements? Electronic structure of atoms Naming delocalized molecular orbitals: tetrahedral and octahedral
More informationMolecular Orbital Theory and Charge Transfer Excitations
Molecular Orbital Theory and Charge Transfer Excitations Chemistry 123 Spring 2008 Dr. Woodward Molecular Orbital Diagram H 2 Antibonding Molecular Orbital (Orbitals interfere destructively) H 1s Orbital
More informationChapter 24. Transition Metals and Coordination Compounds. Lecture Presentation. Sherril Soman Grand Valley State University
Lecture Presentation Chapter 24 Transition Metals and Coordination Compounds Sherril Soman Grand Valley State University Gemstones The colors of rubies and emeralds are both due to the presence of Cr 3+
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 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 informationPAPER No.13 :Applications of molecular symmetry and group theory Module No.35: Symmetry and chemical bonding part-6 MO
1 Subject Chemistry Paper No and Title 13: Applications of molecular symmetry and group theory Module No and Title 35: Symmetry and chemical bonding part-v MO Module Tag CHE_P13_M35 2 TABLE O CONTENTS
More informationChapter 9. Molecular Geometries and Bonding Theories. Lecture Presentation. John D. Bookstaver St. Charles Community College Cottleville, MO
Lecture Presentation Chapter 9 Theories John D. Bookstaver St. Charles Community College Cottleville, MO Shapes The shape of a molecule plays an important role in its reactivity. By noting the number of
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 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 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
Chapter 9 Molecular Geometry and Bonding Theories MOLECULAR SHAPES 2 Molecular Shapes Lewis Structures show bonding and lone pairs do not denote shape Use Lewis Structures to determine shapes Molecular
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 informationCrystal Field Theory. 2. Show the interaction between the d-orbital and the negative point charge ligands
1. What is the crystal field model? Crystal Field Theory It is a model that views complex ions as being held together ionically (this is not actually the case, but it allows for a simplification of the
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 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 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 informationBonding in Octahedral and Tetrahedral Metal Complexes. Predict how the d orbitals are affected by the Metal- Ligand Bonding
Bonding in Octahedral and Tetrahedral Metal Complexes 327 Molecular Orbital Theory and Crystal Field/Ligand Field Theory Predict how the d orbitals are affected by the Metal- Ligand Bonding d z 2, d x
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 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 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 informationChemistry 431. Lecture 14. Wave functions as a basis Diatomic molecules Polyatomic molecules Huckel theory. NC State University
Chemistry 431 Lecture 14 Wave functions as a basis Diatomic molecules Polyatomic molecules Huckel theory NC State University Wave functions as the basis for irreducible representations The energy of the
More informationChapter 20 d-metal complexes: electronic structures and properties
CHEM 511 Chapter 20 page 1 of 21 Chapter 20 d-metal complexes: electronic structures and properties Recall the shape of the d-orbitals... Electronic structure Crystal Field Theory: an electrostatic approach
More informationDr. Fred O. Garces Chemistry 201
23.4 400! 500! 600! 800! The relationship between Colors, Metal Complexes and Gemstones Dr. Fred O. Garces Chemistry 201 Miramar College 1 Transition Metal Gems Gemstone owe their color from trace transition-metal
More informationChapter 8. Molecular Shapes. Valence Shell Electron Pair Repulsion Theory (VSEPR) What Determines the Shape of a Molecule?
PowerPoint to accompany Molecular Shapes Chapter 8 Molecular Geometry and Bonding Theories Figure 8.2 The shape of a molecule plays an important role in its reactivity. By noting the number of bonding
More informationName CHM 4610/5620 Fall 2017 December 14 FINAL EXAMINATION SOLUTIONS Part I, from the Literature Reports
Name CHM 4610/5620 Fall 2017 December 14 FINAL EXAMINATION SOLUTIONS Part I, from the Literature Reports I II III IV V VI VII VIII IX X Total This exam consists of several problems. Rough point values
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 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 informationChm December 2008
Inorganic Exam 3 Chm 451 4 December 2008 Name: Instructions. Always show your work where required for full credit. 1. (15 pts) True/False a T F Ionization energy decreases as one moves down from Li to
More informationThe d-block elements. Transition metal chemistry is d-orbitals/electrons
The d-block elements d-block elements include Sc-Zn, Y-Cd, a(or u)-hg. Transition metal chemistry is d-orbitals/electrons H&S, Fig 1.1, p. 15 Properties of transition metal ions are very sensitive to the
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 informationCr(II) or Cr 2+ Consider the octahedral complex Cr[(en) 3 ] 2+ Octahedral complex with 4 d electrons. Octahedral complex with 4 d electrons
Cr [Ar] 4s 1 3d 5 Cr 2+ [Ar] 3d 4 Consider the octahedral complex Cr[(en) 3 ] 2+ Cr(II) or Cr 2+ Pairing energy Octahedral complex with 4 d electrons Octahedral complex with 4 d electrons Δ is large Δ
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 informationChapter 21. d-block metal chemistry: coordination complexes
Inorganic Chemistry B Chapter 21 d-block metal chemistry: coordination complexes Dr. Said El-Kurdi 1 21.1 Introduction In this chapter, we discuss complexes of the d-block metals and we consider bonding
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 informationPractice Problems: Transition Elements and Coordination Chemistry. # Ligands Coordination # Oxidation #
Practice Problems: Transition Elements and Coordination Chemistry 1. Complete the valence level orbital notation for the following monatomic ions. KEY CHEM 1B a) Ag + b) Co 3+ 4d 5s 3d 4s c) Fe 3+ d) Cr
More informationMo 2+, Mo 2+, Cr electrons. Mo-Mo quadruple bond.
Problem 1 (2 points) 1. Consider the MoMoCr heterotrimetallic complex shown below (Berry, et. al. Inorganica Chimica Acta 2015, p. 241). Metal-metal bonds are not drawn. The ligand framework distorts this
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 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 informationb) For this ground state, obtain all possible J values and order them from lowest to highest in energy.
Problem 1 (2 points) Part A Consider a free ion with a d 3 electronic configuration. a) By inspection, obtain the term symbol ( 2S+1 L) for the ground state. 4 F b) For this ground state, obtain all possible
More informationb) For this ground state, obtain all possible J values and order them from lowest to highest in energy.
Problem 1 (2 points) Part A Consider a free ion with a d 3 electronic configuration. a) By inspection, obtain the term symbol ( 2S+1 L) for the ground state. 4 F b) For this ground state, obtain all possible
More informationNuclear Quadrupole Resonance Spectroscopy. Some examples of nuclear quadrupole moments
Nuclear Quadrupole Resonance Spectroscopy Review nuclear quadrupole moments, Q A negative value for Q denotes a distribution of charge that is "football-shaped", i.e. a sphere elongated at the poles; a
More informationChem Spring, 2017 Assignment 5 - Solutions
Page 1 of 10 Chem 370 - Spring, 2017 Assignment 5 - Solutions 5.1 Additional combinations are p z ± d z 2, p x ±d xz, and p y ±d yz. p z ± d z 2 p x ±d xz or p y ±d yz 5.2 a. Li 2 has the configuration
More informationChapter 9 Molecular Geometry Valence Bond and Molecular Orbital Theory
Chapter 9 Molecular Geometry Valence Bond and Molecular Orbital Theory Chapter Objectives: Learn the basics of Valence Bond Theory and Molecular Orbital Theory and how they are used to model covalent bonding.
More informationChemistry 324 Midterm 1 KEY Wednesday, October 19, 2011 Instructor: D. J. Berg
Chem 324 Midterm 1 Fall 2011 Version 1 Page 1 of 9 Chemistry 324 Midterm 1 KEY Wednesday, October 19, 2011 Instructor: D. J. Berg Name: Answer all questions on the paper (use the back if necessary). There
More information11/9/15. Intermolecular hydrogen bond: Hydrogen bond: Intramolecular hydrogen bond: Induced dipole moment, polarisability
Induced dipole moment, polarisability in electric field: Van der Waals forces Intermolecular forces other than covalent bonds or other than electrostatic interactions of ions induced d. moment µ * = α
More informationChapter 9. and Bonding Theories
Chemistry, The Central Science, 11th edition Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten Chapter 9 Theories John D. Bookstaver St. Charles Community College Cottleville, MO Shapes The
More informationCHEMISTRY - ZUMDAHL 2E CH.4 - MOLECULAR STRUCTURE AND ORBITALS.
!! www.clutchprep.com CONCEPT: ELECTRONIC GEOMETRY When drawing a compound you have to take into account two different systems of geometrical shape. The simpler system known as electronic geometry or shape
More informationSymmetry 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 informationA molecule s color can depend on oxidation state or liganded state. Example: oscillating clock. Consider the overall reaction: -
30.1.111 Lecture Summary #30 Transition Metals Topic: Crystal Field Theory and the Spectrochemical Series. Chapter 16 A molecule s color can depend on oxidation state or liganded state. Example: oscillating
More informationCHAPTER 9 THEORY OF RESONANCE BY, G.DEEPA
CHAPTER 9 THEORY OF RESONANCE BY, G.DEEPA Conjugation in Alkadienes and Allylic Systems conjugation a series of overlapping p orbitals The Allyl Group allylic position is the next to a double bond 1 allyl
More informationChapter 9: Molecular Geometry and Bonding Theories
Chapter 9: Molecular Geometry and Bonding Theories 9.1 Molecular Geometries -Bond angles: angles made by the lines joining the nuclei of the atoms in a molecule -Bond angles determine overall shape of
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 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 informationcharacter table, determine the reducible representation and irreducible components for the σ-bonding SALCs.
Chm 451 with Dr. Mattson Exam 2 Name: 27 October 2011 Earlier this month Dan Shechtman won the Nobel Prize in chemistry for his discovery of quasicrystals such as the one shown at right consisting of silver,
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 informationStructure of Coordination Compounds
Chapter 22 COORDINATION CHEMISTRY (Part II) Dr. Al Saadi 1 Structure of Coordination Compounds The geometry of coordination compounds plays a significant role in determining their properties. The structure
More informationChapter 9. and Bonding Theories. Molecular Shapes. What Determines the Shape of a Molecule? 3/8/2013
Chemistry, The Central Science, 10th edition Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten Chapter 9 Theories John D. Bookstaver St. Charles Community College St. Peters, MO 2006, Prentice-Hall,
More informationName CHM 4610/5620 Fall 2016 December 15 FINAL EXAMINATION SOLUTIONS
Name CHM 4610/5620 Fall 2016 December 15 FINAL EXAMINATION SOLUTIONS I. (80 points) From the literature... A. The synthesis and properties of copper(ii) complexes with ligands containing phenanthroline
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 informationChem 1102 Semester 2, 2011!
Chem 110 Semester, 011! How is the ligand bonded to the metal? In octahedral complexes, six d sp 3 hybrid orbitals are used by the metal. The metal-ligand bond is a two-electron covalent bond. Mix d z,
More informationCHEMISTRY - MCMURRY 7E CH.7 - COVALENT BONDING AND ELECTRON DOT STRUCTURES
!! www.clutchprep.com CONCEPT: ELECTRONIC GEOMETRY When drawing a compound you have to take into account two different systems of geometrical shape. The simpler system known as electronic geometry or shape
More informationDr M. Mehrdad University of Guilan, Department of Chemistry, Rasht, Iran
Dr M. Mehrdad University of Guilan, Department of Chemistry, Rasht, Iran MO theory considers the electrons in molecules to occupy MOs that are formed by linear combinations (addition and subtraction) of
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 informationIf you put an electron into the t 2g, like that for Ti 3+, then you stabilize the barycenter of the d orbitals by 0.4 D o.
Crystal Field Stabilization Energy Week 2-1 Octahedral Symmetry (O h ) If you put an electron into the t 2g, like that for Ti 3+, then you stabilize the barycenter of the d orbitals by 0.4 D o. Each additional
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 informationChem 673, Problem Set 5 Due Thursday, November 29, 2007
Chem 673, Problem Set 5 Due Thursday, November 29, 2007 (1) Trigonal prismatic coordination is fairly common in solid-state inorganic chemistry. In most cases the geometry of the trigonal prism is such
More informationMolecular Structure and Bonding- 2. Assis.Prof.Dr.Mohammed Hassan Lecture 3
Molecular Structure and Bonding- 2 Assis.Prof.Dr.Mohammed Hassan Lecture 3 Hybridization of atomic orbitals Orbital hybridization was proposed to explain the geometry of polyatomic molecules. Covalent
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 information