Coordination Chemistry: Bonding Theories

Slides:

Advertisements

Similar presentations

Crystal Field Theory The relationship between colors and complex metal ions.

Advertisements

Metal Complexes -- Chapter 24

Lecture 10 -Further Consequences of d-Orbital Splitting

Mysteries of polarized light Enantiomers have identical properties except in one respect: the rotation of the plane of polarization of light Enantiomers.

Five Slides About: UV-Vis Spectroscopy and Tanabe-Sugano Diagrams

Ch 10 Lecture 3 Angular Overlap

Which colours are exhibited? colour wheel This colour wheel demonstrates which colour a compound will appear if it only has.

Bonding in complexes of d-block metal ions – Crystal Field Theory. energy egeg t 2g Co 3+ ion in gas-phase (d 6 ) Δ Co(III) in complex 3d sub-shell d-shell.

Coordination Chemistry II

Lecture 22 Electronic structure of Coordination Compounds 1) Crystal Field Theory Considers only electrostatic interactions between the ligands and the.

Lecture 17. Jahn-Teller distortion and coordination number four

Coordination Chemistry Bonding in transition-metal complexes.

Prentice-Hall © 2002 Complex Ions and Coordination Compounds.

Placing electrons in d orbitals (strong vs weak field)

Lecture 28 Electronic Spectra of Coordination Compounds MLx (x = 4,6) 1) Terms of a free d2 metal atom The total number of microstates for an isolated.

6  ligands x 2e each 12  bonding e “ligand character” “d 0 -d 10 electrons” non bonding anti bonding “metal character” ML 6  -only bonding The bonding.

1 Electronic (UV-visible) Spectroscopy ｜ Electronic ｜ XPS UPS UV-visible.

Coordination Chemistry Bonding in transition-metal complexes.

Metal-ligand  interactions in an octahedral environment Six ligand orbitals of  symmetry approaching the metal ion along the x,y,z axes We can build.

Big-picture perspective: The interactions of the d orbitals with their surrounding chemical environment (ligands) influences their energy levels, and this.

Transition Metal Complexes. Transition metal complexes consist of a central Transition metal ion surrounded by a number of ligands. As a result of their.

Lecture 26 MO’s of Coordination Compounds MLx (x = 4,6) 1) Octahedral complexes with M-L s-bonds only Consider an example of an octahedral complex.

Transition Metal Chemistry The Chemistry of the d-block elements.

CHAPTER 5: CRYSTAL FIELD THEORY

1 Chapter 19Coordination Complexes 19.1The Formation of Coordination Complexes 19.2Structures of Coordination Complexes 19.3Crystal-Field Theory and Magnetic.

Crystal Field Theory Focus: energies of the d orbitals Assumptions

Crystal Field Theory The relationship between colors and complex metal ions.

Ch 10 Lecture 2 Ligand Field Theory

Coordination Chemistry:

Chap 24 Part 2 Color and Magnetism  The color of the complex is the sum of the light not absorbed (reflected) by the complex.Color Color of a complex.

Bonding in coordination compounds

Coordination Chemistry II: Bonding

Coordination Chemistry II

Crystal Field Theory i) Separate metal and ligands have high energy ii) Coordinated Metal - ligand get stabilized iii) Metal and Ligands act as point charges.

Transition Metal Chemistry and Coordination Compounds

The Period 4 transition metals. Colors of representative compounds of the Period 4 transition metals titanium oxide sodium chromate potassium ferricyanide.

Coordination Complexes Chapter 20. Copyright © Houghton Mifflin Company. All rights reserved.20 | 2 What we learn from Chap 20 We begin the chapter with.

COORDINATION COMPOUNDS

Crystal Field Theory, Electronic Spectra and MO of Coordination Complexes Or why I decided to become an inorganic chemist or Ohhh!!! The Colors!!!

Synthesis How do I make it? Modeling How do I explain it?

Slide 2/26 Schedule Lecture 1: Electronic absorption spectroscopy Jahn-Teller effect and the spectra of d 1, d 4, d 6 and d 9 ions Lecture 2: Interpreting.

I.Nomenclature of Coordination Complexes A.Ligands 1)Table lists common ligands, names, structures, and abbreviations Chapter 20 Lecture 2 Transition.

CHEM 522 Chapter 01 Introduction. Transition Metal Organometallic Chemistry Organic versus inorganic chemistry Transition metals –Oxidation state –d orbitals.

Crystal Field Theory Molecular Orbital Theory: Donor- Acceptor Interactions.

Pengantar Kimia Koordinasi

NATURE OF THE LIGAND- SMALL LIGANDS APPROACH THE LIGANDS EASILY, SO THEY CAN CAUSE GREAT CRYSTAL FIELD SPLITTING. LIGANDS CONTAINING EASILY POLARISABLE.

Co-ordination Chemistry Theories of Bonding in Co-ordination compound. 1. Valence Bond Theory 2. Crystal Field Theory 3. Molecular Orbital Theory.

Ligand field theory considers the effect of different ligand environments (ligand fields) on the energies of the d- orbitals. The energies of the d orbitals.

TOPIC 13 THE PERIODIC TABLE- THE TRANSITION METALS 13.2 COLOURED COMPLEXES.

Sub-Topics Introduction to Transition Metals

Transition-Metal Complexes are extremely colorful!

Figure 23.2 Radii of transition metals as a function of group number.

INORGANIC CHEMISTRY CHEMISTRY 340. MAIN THEMES OF INORGANIC CHEMISTRY Periodic Properties and Periodic Trends Point Groups and Symmetry The 18 electron.

COORDINATION COMPOUNDS

Coordination complexes

Coordination Chemistry Bonding in transition-metal complexes

metal ion in a spherical

Applications of Crystal Field Theory: Ionic Radii

Metal-Ligand bonding in transition metal complexes

Dear Students of Inorganic Chemistry 2,

Metal-Ligand bonding in transition metal complexes

Crystal Field Theory The relationship between colors and complex metal ions.

Transition Metal Chemistry: Crystal Field Theory

Physical Chemistry Chapter V Polyatomic Molecular Structure 2019/4/10

semester 2 Lecture note 1 Crystal Field Theory

Invisible Ink 2[Co(H2O)6]Cl2(s) Co[CoCl4](s) + 12 H2O

Transition Metals and Color

Understanding the Absorption Electronic Spectra of Coordination Compounds at greater depth Ligand Field Theory Chapter 20.

Presentation transcript:

Coordination Chemistry: Bonding Theories Coordination Chemistry: Bonding Theories Chapter 20 Chapter 20 1

2 1. Chemistry of the d-orbitals

2. Crystal Field Theory 3 A purely electrostatic consideration  Ligand electrons create an electric field around the metal center  Ligands are point charges and we do not take their orbitals into consideration  No metal-ligand covalent interactions

3. Energy of the d-orbitals 4 Degenerate 3d atomic orbitals

4. The Octahedral Crystal Field 5 Octahedral coordination environment:  Point Group: O h  d z 2 and d x 2 – y 2 orbitals: e g symmetry  d xy, d xz, and d yz : t 2g symmetry Destabilized Stabilized

A. The Magnitude of Δ oct 6 Determined by the strength of the crystal field:  Weak field  Strong field Δ oct (weak field) < Δ oct (strong field) d 5 electron configuration

B. Crystal Field Stabilization Energy (CFSE) 7 Consider a d 1 electron configuration: i.e. [Ti(H 2 O) 6 ] 3+ Ti 3+ Δ oct Electronic absorbance  The single electron will be in less energetic ground state. Ground State

C. CFSE and High vs Low Spin 8 Consider a d 4 electron configuration (Cr 2+ ):  Pairing has to be invoked Δ oct < p (pairing energy) Weak Field, High spin Δ oct > p Strong Field, Low spin t 2g 3 e g 1 t 2g 4 CFSE = [ 3 x 0.4Δ oct ] - [ 1 x 0.6Δ oct ] = 0.6Δ oct CFSE = [ 4 x 0.4Δ oct ] = 1.6Δ oct – 1 p

I. What determines Δ? 9 i.Oxidation state of the metal ion  Δ with ionic charge ii.Nature of M 3d < 4d < 5d Really big Δ, normally low spin (As you go down the periodic table, Δ) iii.Number and geometry of ligands Δ tetrahedral only ~50% of Δ octahedral

II. What determines Δ? 10 iv. Nature of ligands  Spectrochemical series (partial) I - < Br - < [NCS] - < Cl - < F - < [OH] - < [ox] 2- ~ H 2 O < [NCS] - < NH 3 < en < [CN] - ~ CO Weak field ligands Strong field ligands Ligands increasing Δ oct YOU CAN NOT UNDERSTAND THIS TREND WITH CRYSTAL FIELD THEORY

II. What determines Δ? 11 iv. Nature of ligands  Spectrochemical series (partial) The strength of a ligand determines the Δ oct - Splitting of [CoF 6 ] 3- - Splitting of [Fe(H 2 O)] 3+ I - < Br - < [NCS] - < Cl - < F - < [OH] - < [ox] 2- ~ H 2 O < [NCS] - < NH 3 < en < [CN] - ~ CO Weak field ligands Strong field ligands Ligands increasing Δ oct

5. Octahedral Geometry Distortions 12 D 4h OhOh dz2dz2 d x 2 – y 2 dz2dz2 d xy d xz d yz d xz d yz d xy d xz d yz d x 2 – y 2 dz2dz2 What about a d 1 electron configuration? No YES!!! Degeneracy Removed