PAPER No. : 11 and Inorganic Chemistry MODULE No.3 : and Structure of metal carbonyls and 18-electron rule applied to them. Paper No and Title
|
|
- Gavin George
- 5 years ago
- Views:
Transcription
1 Subject Chemistry Paper No and Title Module No and Title Module Tag 11 : Inorganic Chemistry 3 : Structure of metal carbonyls and 18-electron rule applied to them CHE_P11_M3
2 TABLE OF CONTENTS 1. Learning Outcomes 2. Introduction 3. Techniques used for the determination of metal carbonyls 3.1. Structure of mononuclear metal carbonyls 3.2. Structure of dinuclear metal carbonyls 3.3 Structure of trinuclear metal carbonyls 3.4 Structure of tetranuclear metal carbonyls Electron rule Electron rule applied to metal carbonyls 5. Summary
3 1. Learning Outcomes After studying this module, you shall be able to Know about structures of various metal carboyl Learn about various techniques used in determining the structure of metal carbonyl Identify structure of metal carbonyl Evaluate electron count of a complex 2. Introduction Carbonyl ligand displays a variety of bonding modes in their metal complexes such as terminal and bridging. Due to large number of bonding modes, the structural determination of metal carbonyl complexes is extremely important. The structures of metal carbonyls are determined with the help of various spectroscopic and diffraction studies such as X-ray diffraction, infrared spectroscopy and electron diffraction studies. Mononuclear metal carbonyls have only linear linkage. The polynuclear metal carbonyls have some other type of linkages also such as: i) M M (metal metal) bond ii) bent M CO M linkage. The terminal and bridging carbonyl groups can be distinguished with the help of IR spectroscopy. The terminal carbonyl group exhibits absorption in the range cm -1 while the bridging carbonyl group does so in the range cm -1. The shape of a metal carbonyl depends upon the nature of hybridisation on central metal. Tetrahedral, trigonl bipyramdal and octahedral are the common geometries for metal carbonyls. CO is a strong ligand and it has a tendency to pair up the electrons of the metal atom in the inner orbitals and thus metal carbonyls are inner orbital complexes and most of them follow 18- electron rule with few exceptions.
4 3. Techniques used for the determination of metal carbonyls: The structures of homoleptic metal carbonyls such as V(CO) 6, Cr(CO) 6, Fe(CO) 5, and Ni(CO) 4 have been established by X- ray diffraction, infrared spectroscopy and electron diffraction studies. The structures of Mo(CO) 6 and W(CO) 6 have been established by X- ray diffraction studies. The mononuclear metal carbonyls have only one type O linkage and it is the linear linkage. The polynuclear metal carbonyls have some other type of linkages also in addition to the aforesaid linear linkage such as i) M M (metal metal bond) ii) bent bridging C carbonyl linkage. M M The M M bond has been established by the measurement of magnetic susceptibility and calculation of magnetic moment. The formation of metal metal bond involves the pairing up of unpaired electrons of metals leading to the diamagnetism. All the metal carbonyls whether mononuclear or polynuclear (except V(C0) 6 ) are diamagnetic,i.e., they have no unaired electrons. The presence of bridging carbonyl group in a polynuclear metal carbonyl has been established by infrared spectroscopy. The bridging carbonyl group exhibits absorption peak in the range cm -1 due to its stretching mode of vibration. On other hand the terminal carbonyl group exhibits absorption peak in the range cm -1 in the infrared spectrum due to its stretching mode of vibration. Thus the linear and bridging carbonyl groups of polynuclear metal carbonyls can be distinguished with help of infrared spectroscopy. 3.1 Structure of mononuclear metal carbonyls: The mononuclear metal carbonyls have only M C O linear linkage and their structure depends upon the coordination number of metal, i.e., number of carbonyl groups attached to the metal and the type of hybridization on central metal. The structure of Ni (CO) 4 has been established to be tetrahedral from various studies. The nickel atom of this complex is sp 3 hybridised. [Co(CO) 4 ] - and [Fe(CO) 4 ] 2- are isoelectronic to [Ni(CO) 4 ] and hence they also have tetrahedral structure.
5 The pentacarbonyls such as Fe(CO) 5, Ru(CO) 5 and Os(CO) 5 have trigonal bipyramidal structure arising from dsp 3 hybridisation on the central metal. [Mn(CO) 5 ] - is isoelectronic to Fe(CO) 5 and it also has trigonal bipyramidal structure. The hexacacarbonyls such as V(CO) 6, Cr(CO) 6, Mo(CO) 6 and W(CO) 6 have octahedral structure arising from d 2 sp 3 hybridisation on the central metal. [V(CO) 6 ] -, [Nb(CO) 6 ] -, [Ta(CO) 6 ] - and [Mn(CO) 6 ] + also have octahedral structure. 3.2 Structure of dinuclear metal carbonyls: a) M 2 (CO) 10 type dinuclear metal carbonyls: The infrared absorption spectral and X-rays diffraction studies on Mn 2 (CO) 10 molecule suggest that in this molecule,each Mn atom is directly attached to other Mn atom by a Mn Mn σ-bond which is formed by the linear overlapping of singly occupied d 2 sp 3 hybrid orbitals and five terminal carbonyl groups through a Mn C O coordinate bond. The presence of Mn Mn bond in Mn 2 (CO) 10 molecule is further supported by its diamagnetic character and short Mn Mn distance(2.79 Å).Thus the coordination number of each manganese atom in Mn 2 (CO) 10 molecule is 6.This molecule contains a linear linkage as shown below: O C Mn Mn C O At the same time, Mn 2 (CO) 10 molecule contains two square planar Mn(CO) 4 moieties in staggered conformation and hence the point group of Mn 2 (CO) 10 molecule is D 4d.
6 It is obvious that Mn 2 (CO) 10 molecule may be regarded as two distorted octahedral sharing one corner. Tc 2 (CO) 10 and Re 2 (CO) 10 have structures similar to Mn 2 (CO) 10. b) Co 2 (CO) 8 : The infrared spectral studies made on Co 2 (CO) 8 in n-heptane solvent suggest that it occurs in two isomeric forms which are in temperature dependent equilibrium with each other Å 2.52 Å (Non-bridged structure) (Bridged structure) At room temperature, both bridged and non- bridged structures of Co 2 (CO) 8 are present in almost equal proportions. At higher temperatures the non-bridged structure dominates while at lower temperatures the bridged structure dominates. The standard enthalpy of conversion of bridged structure into non-bridged structure is +5.5 kj/mol but it is accompanied by an increase in entropy so that there is very little difference in Gibbs energy of two forms of Co 2 (CO) 8. In the bridged structure of Co 2 (CO) 8, each Co atom is attached to three terminal carbonyl groups, two bridging carbonyl groups and one other Co atom. The Co Co bond is formed by the bent or angular overlapping of singly occupied d 2 sp 3 hybrid orbitals of two Co atoms. The Co Co distance is 2.52 Å and coordination number of Co is 6.
7 (Bridged structure of Co 2 (CO) 8 ) In the non-bridged structure of Co 2 (CO) 8, each Co atom is attached to four terminal carbonyl groups and on other Co atom. The Co Co bond is formed by the linear overlapping of singly occupied dsp 3 hybrid orbitals of two Co atoms and its length is slightly greater (2.70 Å ) due to the absence of bridging carbonyl groups. The coordination number of Co is 5 with trigonal bipyramidal arrangement around it. (Non-bridged structure of Co 2 (CO) 8 ) The X-ray diffraction studies of the crystals of Co 2 (CO) 8 indicates that the molecule has bridged structure. c) Fe 2 (CO) 9 : The infrared absorption spectral and and X- rays diffraction of the crystals of Fe 2 (CO) 9 suggest that in the molecule, each Fe atom is attached to three terminal carbonyl groups, three bridging carbonyls and one other Fe atom. The Fe Fe bond is formed by the lateral overlapping of singly occupied d xy atomic orbitals of two Fe atoms involving four overlap zones and thus it is a δ- bond.
8 2.46 Å The coordination number of Fe atom in Fe 2 (CO) 9 is 7 rather than 6. Thus the Fe 2 (CO) 9 molecule consists of two octahedral sharing a triangular face containing three bridging carbonyl groups. Os 2 (CO) 9 is suggested to have Os Os bond but with only one carbonyl group. 3.3 Structure of trinuclear metal carbonyls: Iron, ruthenium and osmium of group 8 of the periodic table form trinuclear metal carbonyls of the type M 3 (CO) 12.The X-rays diffraction and infrared absorption spectral studies made on Fe 3 (CO) 12 suggest that the molecule has following structural features: Two Fe atoms are linked by Fe Fe covalent bond. Each of above two Fe atoms is attached to three terminal carbonyl groups. Each of above two Fe atoms is attached to two bridging carbonyl groups. Each of above two Fe atoms is attached to a third Fe atom by covalent bond. There are three Fe Fe bonds of equal lengths (2.80 Å). The third Fe atom is attached to four terminal carbonyl groups and no bridging carbonyl group.
9 Ru 3 (CO) 12 and Os 3 (CO) 12 have triangular planar arrangement of three metal atoms which are held together by three M M bonds. Each metal atom is attached to four terminal carbonyl groups and no bridging carbonyl group Structure of tetranuclear metal carbonyls: Cobalt, rhodium and iridium of group 9 of the periodic table form tetranuclear metal carbonyls of the type M 4 (CO) 12. In the molecule of Co 4 (CO) 12, Co atoms are present at the corners of a tetrahedron. Each of the three Co atoms present at the corners of a triangular face is attached to two terminal carbonyl groups, two bridging carbonyl groups and three other Co atoms. Thus the coordination number of Co atom is 7.The remaining fourth Co atom is attached to three terminal
10 carbonyl groups, three other Co atoms and no bridging carbonyl group.thus the coordination number of this Co atom is 6. Rh 4 (CO) 12 has structure similar to Co 4 (CO) 12.But Ir 4 (CO) 12 has different structure. Four Ir atoms are present at the corners of a regular tetrahedron. Each Ir atom is attached to three terminal carbonyl groups and three other Ir atoms but no bridging carbonyl groups. Its structure is given below: Thus the coordination number of each Ir is Electron rule: Sidwick made an attempt to explain the nature of bonding in transition metal complexes on the basis of electronic concept. According to him, the ligands act as Lewis base and the metal ion acts Lewis acid. Each ligand usually donates one electron pair to the metal ion during the formation of complex compound. The complex compounds in which the central metal atom or ion acquires noble gas electronic configuration are stable. On this basis the effective atomic number rule was proposed as follows:
11 The sum of the electrons on the central metal atom or ion and the electrons donated from the ligands in a complex compound is called the effective atomic number (EAN) of the metal and for stable complexes it is generally equal to the atomic number of next incoming noble gas. EAN = No. of electrons in the central metal atom or ion + No. of electrons donated by ligands For example, the EAN of Cr in Cr (CO) 6 can be calculated as follows: No of electrons in Cr atom = 24 No. of electrons donated by 6CO=2X6=12 EAN of Cr in Cr (CO) 6 =36 Thus the EAN of Cr in Cr (CO) 6 is 36 which is the atomic no. of next incoming noble gas to Cr,i.e., Kr. It is obvious that Cr (CO) 6 obeys EAN rule and hence it is a stable complex. An alternative and more general statement can be given instead of EAN rule as follows: When the central metal ion or atom of a complex compound acquires noble gas electronic configuration (n-1)d 10 ns 2 np 6 there will be 18 electrons in the valence orbitals (or valence shell) and the electronic configuration will be closed and stable. It is known as the 18-electron rule. The complexes obeying the 18-electron rule are quite stable Electron rule applied to metal carbonyls The 18 electron rule is very useful in predicting stabilities and structures of organometallic compounds. There are two conventions for counting electrons in complexes: a) Neutral atom or covalent model b) Oxidation state or ionic model Both the conventions have almost equal number of supporters and both the methods lead to exactly the same net result. The covalent model is probably more foolproof because it does not require the correct assignment of oxidation states, which is sometimes a difficult job in the case of organometallic compounds. Let us illustrate above two methods by counting electrons in HCo(CO) 4. According to the covalent model there is covalent bond between Co and H atoms in HCo(CO) 4 and H atom acts as 1e donor ligand. Accordingly, no. of electrons in valence shell of Co in HCo(CO) 4 =9(Co) + 4x2(CO) + 1X1(H) = 18 According to the ionic model there is ionic bond between (OC) 4 Co + and H - ions and H - ion acts as 2e - donor ligand. Accordingly, no. of electrons in valence shell of Co in HCo(CO) 4 = 8(Co + ) + 4x2(CO) + 1x2(H - ) = 18 The steps are generally followed for counting the electrons present in the valence shell of central metal in a metal carbonyl.
12 i) The electrons present in the valence shell [i.e., (n-1)d, ns and np orbitals] of the central metal atom are counted and then electrons are added to it or subtracted from it depending upon the nature of charge (negative or positive ) present on it in the metal carbonyl. ii) Each terminal carbonyl group contributes 2e to the valence shell of the central metal. iii) The bridging carbonyl group (M CO M) contributes 1e to the valence shell of each metal atom attached by it. iv)the metal-metal (M M) bond contributes 1e to the valence shell of each metal atom. v) According to the covalent model of electron count, H atom, halogen (X) atom and alkyl groups(r) contribute 1e each to the valence shell of central metal. vi)the electrons donated by the conventional ligands to the valence shell of central metal are also counted. vii) The electrons counted in steps (i) to (vi) are added to find out the total number of electrons in the valence shell of the central metal of metal carbonyl. Some examples of electron counts in the metal carbonyls are given in the following table: Metal carbonyl Electron count of central metal atom(covalent Total electron model) Ni(CO) 4 10(Ni)+4x2(CO) 18 Fe(CO) 5 8(Fe)+5x2(CO) 18 Cr(CO) 6 6(Cr)+6x2(CO) 18 Mn 2 (CO) 10 7(Mn)+5x2(CO)+1X1(Mn Mn) 18 Co 2 (CO) 8 9(Co) +3x2(CO)+2X1(bridging CO)+1X1(Co C o) 18 Fe 2 (CO) 9 8(Fe) +3x2(CO)+3X1(bridging CO)+1X1(Fe Fe) 18 Mn(CO) 5 (CH 3 ) 7(Mn)+5x2(CO)+1X1(CH 3 ) 18 Mn(CO) 5 Cl 7(Mn)+5x2(CO)+1X1(Cl) 18 Os 2 (CO) 9 8(Os)+4x2(CO)+1x1(bridging CO)+1X1(Os Os) 18 Os 3 (CO) 12 8(Os)+4x2(CO)+2X1(Os Os) 18 Ir 4 (CO) 12 9(Ir)+3x2(CO)+3X1(Ir Ir) 18 Na 2 [ Fe(CO) 4 ] 10(Fe 2- )+4x2(CO) 18 V(CO) 6 5(V) +6x2(CO) Summary The shape of a metal carbonyl depends upon the nature of hybridisation on central metal CO is a strong ligand and it can be bonded to the metal atom in two different ways forming metal carbonyls CO molecule can be coordinated to the metal atom in a linear fashion as M C O Such a carbonyl group is called terminal carbonyl group.
13 CO molecule can be coordinated to two metal atoms O C simultaneously as. M M Such a carbonyl group is called bridging carbonyl group The terminal and bridging carbonyl groups can be distinguished with the help of IR spectroscopy The terminal carbonyl group exhibits absorption in the range cm -1 while the bridging carbonyl group does so in the range cm -1 Tetrahedral, trigonal bipyramidal and octahedral are the common geometries for metal carbonyls The number of electrons in the central metal of a complex compound including those donated by ligands is called its effective atomic number The effective atomic number of the central metal in a metal carbonyl is invariably equal to the atomic of next noble gas to it. When the central metal ion or atom of a complex compound acquires noble gas electronic configuration (n-1)d 10 ns 2 np 6 there will be 18 electrons in the valence orbitals (or valence shell) and the electronic configuration will be closed and stable. It is known as 18- electron rule. Most of the metal carbonyls obey 18-electron rule and hence they are significantly stable. V(CO) 6 is the only metal carbonyl which does not obey 18-electron rule.
11, Inorganic Chemistry III (Metal π-complexes and Metal Clusters) Module 32: Polynuclear metal carbonyls and their structure
1 Subject Paper No and Title Module No and Title Module Tag Chemistry 11, Inorganic Chemistry III (Metal π-complexes and Module 32: Polynuclear metal carbonyls and their structure CHE_P11_M32 2 TABLE OF
More informationPAPER No.11 : Inorganic Chemistry-II MODULE No.1 : Π-acceptor ligand, metal carbonyls, bonding modes of CO, classification of metal carbonyls
Subject Paper No and Title Module No and Title Module Tag 11: INORGANIC CHEMISTRY-III (METAL π- COMPLEXES AND METAL CLUSTERS) 1: π-acidity, Metal carbonyls, their classification and general features CHE_P11_M1
More informationPAPER No.11: Inorganic Chemistry-III MODULE No.29: Metal- metal bonds and their evidences
1 Subject Chemistry Paper No and Title Module No and Title Module Tag 11: Inorganic Chemistry-III (Metal π-complexes and Metal Clusters) 29: Metal-metal bonds and their evidences CHE_P11_M29 2 TABLE OF
More informationDownloaded from
1 Class XII: Chemistry Chapter 9: Coordination Compounds 1. Difference between coordination compound and double bond: Coordination compound A coordination compound contains a central metal atom or ion
More informationB. Electron Deficient (less than an octet) H-Be-H. Be does not need an octet Total of 4 valence electrons
B. Electron Deficient (less than an octet) e.g. BeH 2 H-Be-H Be does not need an octet Total of 4 valence electrons Not the same as unsaturated systems that achieve the 8e - (octet) through the formation
More informationCBSE Class-12 Chemistry Quick Revision Notes Chapter-09: Co-ordination Compounds
CBSE Class-12 Chemistry Quick Revision Notes Chapter-09: Co-ordination Compounds Co-ordination compounds: a) A coordination compound contains a central metal atom or ion surrounded by number of oppositely
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 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 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 informationAP CHEMISTRY CHAPTERS 5 & 6 Problem Set #4. (Questions 1-13) Choose the letter that best answers the question or completes the statement.
NAME: AP CHEMISTRY CHAPTERS 5 & 6 Problem Set #4 (Questions 1-13) Choose the letter that best answers the question or completes the statement. (Questions 1-2) Consider atoms of the following elements.
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 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 informationOrganic Chemistry. Review Information for Unit 1. VSEPR Hybrid Orbitals Polar Molecules
rganic hemistry Review Information for Unit 1 VSEPR ybrid rbitals Polar Molecules VSEPR The valence shell electron pair repulsion model (VSEPR) can be used to predict the geometry around a particular atom
More informationBonding in Molecules Covalent Bonding
Bonding in Molecules Covalent Bonding The term covalent implies sharing of electrons between atoms. Valence electrons and valence shell orbitals - nly valence electrons are used for bonding: ns, np, nd
More informationGeneral and Inorganic Chemistry I.
General and Inorganic Chemistry I. Lecture 1 István Szalai Eötvös University István Szalai (Eötvös University) Lecture 1 1 / 29 Outline István Szalai (Eötvös University) Lecture 1 2 / 29 Lewis Formulas
More informationHybridisation of Atomic Orbitals
Lecture 7 CHEM101 Hybridisation of Atomic Orbitals Dr. Noha Osman Learning Outcomes Understand the valence bond theory Understand the concept of hybridization. Understand the different types of orbital
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 informationCoordination chemistry and organometallics
Coordination chemistry and organometallics Double salt and Complex salt A salt that keeps its identity only in solid state is called a double salt. In solution they dissociate into component ions. E.g.:
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 information11/14/2014. Chemical Bonding. Richard Philips Feynman, Nobel Laureate in Physics ( )
Chemical Bonding Lewis Theory Valence Bond VSEPR Molecular rbital Theory 1 "...he [his father] knew the difference between knowing the name of something and knowing something" Richard Philips eynman, Nobel
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 informationBonding/Lewis Dots Lecture Page 1 of 12 Date. Bonding. What is Coulomb's Law? Energy Profile: Covalent Bonds. Electronegativity and Linus Pauling
Bonding/Lewis Dots Lecture Page 1 of 12 Date Bonding What is Coulomb's Law? Energy Profile: Covalent Bonds Electronegativity and Linus Pauling 2.1 H 1.0 Li 0.9 Na 0.8 K 0.8 Rb 0.7 Cs 0.7 Fr 1.5 Be 1.2
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 informationExperiment 21 Lewis structures and VSEPR Theory
Experiment 21 Lewis structures and VSEPR Theory Introduction 1. Lewis Structures and Formal Charge LG.N. Lewis, at the University of California at Berkeley devised a simple way to understand the nature
More informationLecture Presentation. Chapter 10 Chemical Bonding II: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory
Lecture Presentation Chapter 10 Chemical Bonding II: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory Predicting Molecular Geometry 1. Draw the Lewis structure. 2. Determine the number
More informationPaper 3: (Stereochemistry, Metal-Ligand Equilibria and Reaction Mechanism of Transition Metal Complexes)
Subject Paper No and Title Module No and Title Module Tag 4, Bent rule and energetics of hybridisation CHE_P3_M4 TABLE OF CONTENTS 1. Learning Outcomes 2. Introduction 2.1 Bent rule and energetics of hybridization
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 informationChapters 9&10 Structure and Bonding Theories
Chapters 9&10 Structure and Bonding Theories Ionic Radii Ions, just like atoms, follow a periodic trend in their radii. The metal ions in a given period are smaller than the non-metal ions in the same
More informationCovalent Compounds: Bonding Theories and Molecular Structure
CHM 123 Chapter 8 Covalent Compounds: Bonding Theories and Molecular Structure 8.1 Molecular shapes and VSEPR theory VSEPR theory proposes that the geometric arrangement of terminal atoms, or groups of
More informationChapter 6 PRETEST: Chemical Bonding
Chapter 6 PRETEST: Chemical In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question. 1.The charge on an ion is a. always positive.
More informationChapter 10: Modern Atomic Theory and the Periodic Table. How does atomic structure relate to the periodic table? 10.1 Electromagnetic Radiation
Chapter 10: Modern Atomic Theory and the Periodic Table How does atomic structure relate to the periodic table? 10.1 Electromagnetic Radiation Electromagnetic (EM) radiation is a form of energy that exhibits
More informationChapter 9. Covalent Bonding: Orbitals
Chapter 9 Covalent Bonding: Orbitals Localized electron model A bond is made when a half-filled orbital of one atom overlaps with a half-filled orbital of another.! Bond: orbitals overlap straight on p
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 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 informationChemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals
Chemical Bonding II: and ybridization of Atomic rbitals Chapter 10 Valence shell electron pair repulsion (VSEPR) model: Predict the geometry of the molecule from the electrostatic repulsions between the
More informationCSIR-UGC-NET/JRF GATE CHEMISTRY TEST : ORGANOMETALLIC COMPOUNDS
1 CSIR-UGC-NET/JRF GATE CHEMISTRY TEST : ORGANOMETALLIC MPOUNDS Time 00 : Hour Date : 1-10-2017 M.M. : 0 INSTRUCTION : 1. There are Two Parts. Part-A contains 10 objective type questions, each question
More informationCHAPTER 6 CHEMICAL BONDING SHORT QUESTION WITH ANSWERS Q.1 Dipole moments of chlorobenzene is 1.70 D and of chlorobenzene is 2.5 D while that of paradichlorbenzene is zero; why? Benzene has zero dipole
More informationAt the end of this lesson, students should be able to :
At the end of this lesson, students should be able to : (a) Explain Valence Shell Electron Pair Repulsion theory (VSEPR) (b) Draw the basic molecular shapes: linear, planar, tetrahedral, and octahedral.
More informationCoordination compounds
Coordination compounds Multiple choice questions 1. In the complex formation, the central metal atom / ion acts as a) Lewis base b) Bronsted base c) Lewis acid d) Bronsted acid 2. The groups satisfying
More informationCHAPTER TEN MOLECULAR GEOMETRY MOLECULAR GEOMETRY V S E P R CHEMICAL BONDING II: MOLECULAR GEOMETRY AND HYBRIDIZATION OF ATOMIC ORBITALS
CHAPTER TEN CHEMICAL BONDING II: AND HYBRIDIZATION O ATOMIC ORBITALS V S E P R VSEPR Theory In VSEPR theory, multiple bonds behave like a single electron pair Valence shell electron pair repulsion (VSEPR)
More information"What Do I Remember From Introductory Chemistry?" - A Problem Set
1 "What Do I Remember From Introductory Chemistry?" - A Problem Set These problems review a portion of the material from introductory chemistry that you should be very familiar with. 1. The electron configuration
More information11, Inorganic Chemistry III (Metal π-complexes and Metal Clusters) Module 31: Preparation and reactions of metal clusters
1 Subject Paper No and Title Module No and Title Module Tag Chemistry 11, Inorganic Chemistry III (Metal π-complexes and Module 31: Preparation and reactions of metal clusters CHE_P11_M31 2 TABLE OF CONTENTS
More informationUnit Six --- Ionic and Covalent Bonds
Unit Six --- Ionic and Covalent Bonds Electron Configuration in Ionic Bonding Ionic Bonds Bonding in Metals Valence Electrons Electrons in the highest occupied energy level of an element s atoms Examples
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 informationSubtopic 4.2 MOLECULAR SHAPE AND POLARITY
Subtopic 4.2 MOLECULAR SHAPE AND POLARITY 1 LEARNING OUTCOMES (covalent bonding) 1. Draw the Lewis structure of covalent molecules (octet rule such as NH 3, CCl 4, H 2 O, CO 2, N 2 O 4, and exception to
More informationChapter 21: Transition Metals and Coordination Chemistry
Chapter 21: Transition Metals and Coordination Chemistry Mg, Cr, V, Co Pt Fe complexes O2 Mo and Fe complexes: nitrogen fixation Zn: 150 Cu, Fe: Co: B12 21.1 Transition Metals show great similarities within
More informationChemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 10
Chemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 10 Linear Trigonal 180 o planar 120 o Tetrahedral 109.5 o Trigonal Bipyramidal 120 and 90 o Octahedral 90 o linear Linear
More informationCHEM 101: CHAPTER 11: CHEMICAL BONDS: THE FORMATION OF COMPOUNDS FROM ATOMS
1 CHEM 101: CHAPTER 11: CHEMICAL BONDS: THE FORMATION OF COMPOUNDS FROM ATOMS PERIODIC TRENDS: See pages 214-216, 221 Table 11.3, and 227 + 228 of text. Lewis Structures of Atoms: The Lewis Dot Diagram
More informationUnit 3 - Chemical Bonding and Molecular Structure
Unit 3 - Chemical Bonding and Molecular Structure Chemical bond - A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together 6-1 Introduction
More informationUNIVERSITY OF VICTORIA. CHEMISTRY 101 Mid-Term Test 2, November
NAME Student No. SECTIN (circle one): A01 (Codding) A02 (Sirk) A03 (Briggs) Version A UNIVERSITY F VICTRIA CEMISTRY 101 Mid-Term Test 2, November 19 2010 Version A This test has two parts and 8 pages,
More informationLewis Dot Structures for Methane, CH 4 The central C atom is bonded by single bonds (-) to 4 individual H atoms
Chapter 10 (Hill/Petrucci/McCreary/Perry Bonding Theory and Molecular Structure This chapter deals with two additional approaches chemists use to describe chemical bonding: valence-shell electron pair
More informationChapter 7. Chemical Bonding I: Basic Concepts
Chapter 7. Chemical Bonding I: Basic Concepts Chemical bond: is an attractive force that holds 2 atoms together and forms as a result of interactions between electrons found in combining atoms We rarely
More informationChapter 13: Phenomena
Chapter 13: Phenomena Phenomena: Scientists measured the bond angles of some common molecules. In the pictures below each line represents a bond that contains 2 electrons. If multiple lines are drawn together
More information1. There are paired and unpaired electrons in the Lewis symbol for a phosphorus atom. a. 4, 2 b. 2, 4 c. 2, 3 d. 4, 3 e. 0, 3
Name: Score: 0 / 42 points (0%) [2 open ended questions not graded] C8&9Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1. There are paired and unpaired
More informationCHM2045 F13--Exam # MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
CHM2045 F13--Exam #2 2013.10.18 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A valid Lewis structure of cannot be drawn without violating the
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 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 informationExperiment 15. The Valence Shell Electron Pair Repulsion (VSEPR) Theory of Directed Valency: An exercise
Experiment 15 The Valence Shell Electron Pair Repulsion (VSEPR) Theory of Directed Valency: An exercise Attempts to understand and predict the shapes of molecules using either the valencebond theory or
More informationChemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals
Chemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals 1 Chemical Bonding II Molecular Geometry (10.1) Dipole Moments (10.2) Valence Bond Theory (10.3) Hybridization of Atomic Orbitals
More informationTransition Elements. pranjoto utomo
Transition Elements pranjoto utomo Definition What is transition metal? One of which forms one or more stable ions which have incompletely filled d orbitals. 30Zn? Definition Zink is not transition elements
More informationChapter 25 Transition Metals and Coordination Compounds Part 1
Chapter 25 Transition Metals and Coordination Compounds Part 1 Introduction The transition elements are defined as: those metallic elements that have a partially but incompletely filled d subshell or easily
More informationChapter 9 Molecular Geometry. Lewis Theory-VSEPR Valence Bond Theory Molecular Orbital Theory
Chapter 9 Molecular Geometry Lewis Theory-VSEPR Valence Bond Theory Molecular Orbital Theory Sulfanilamide Lewis Structures and the Real 3D-Shape of Molecules Lewis Theory of Molecular Shape and Polarity
More informationChapter 9 Molecular Geometry and Bonding Theories
Chapter 9 Molecular Geometry and Bonding Theories molecular shapes the VSEPR model molecular shape and molecular polarity covalent bonding and orbital overlap hybrid orbitals multiple bonds 9.1 Molecular
More informationValence Shell Electron Pair repulsion
Molecular Geometry Valence Shell Electron Pair repulsion The valence shell electron pair repulsion model (VSEPR model) assumes that electron pairs repel one another. (VSEPR) model gives helps determine
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 informationIntroduction to VSEPR Theory 1
1 Class 8: Introduction to VSEPR Theory Sec 10.2 VSEPR Theory: The Five Basic Shapes Two Electron Groups: Linear Geometry Three Electron Groups: Trigonal Planar Geometry Four Electron Groups: Tetrahedral
More informationChapter 21 Transition Metals and Coordination Chemistry
Chapter 21 Transition Metals and Coordination Chemistry Some History In the 19 th century, chemists started to prepare colored compounds containing transition metals and other substances like ammonia,
More informationChapter 21 Transition Metals and Coordination Chemistry
Chapter 21 Transition Metals and Coordination Chemistry Some History In the 19 th century, chemists started to prepare colored compounds containing transition metals and other substances like ammonia,
More informationLewis structures show the number and type of bonds between atoms in a molecule or polyatomic ion.
VSEPR & Geometry Lewis structures show the number and type of bonds between atoms in a molecule or polyatomic ion. Lewis structures are not intended to show the 3-dimensional structure (i.e. shape or geometry)
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 informationClass XI Chapter 4 Chemical Bonding and Molecular Structure Chemistry
Class XI Chapter 4 Chemical Bonding and Molecular Structure Chemistry Question 4.1: Explain the formation of a chemical bond. A chemical bond is defined as an attractive force that holds the constituents
More informationClass XI Chapter 4 Chemical Bonding and Molecular Structure Chemistry
Class XI Chapter 4 Chemical Bonding and Molecular Structure Chemistry Question 4.1: Explain the formation of a chemical bond. A chemical bond is defined as an attractive force that holds the constituents
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 informationBonding. Honors Chemistry 412 Chapter 6
Bonding Honors Chemistry 412 Chapter 6 Chemical Bond Mutual attraction between the nuclei and valence electrons of different atoms that binds them together. Types of Bonds Ionic Bonds Force of attraction
More information2 electrons 2s 2 2p 6. 8 electrons (octet rule) 3s 2 3p 6 3d 10
Main Group and Transition Metal Chemistry: Reading: Moore chapter 22, sections 22.1, 22.6 Questions for Review and Thought: 14, 16, 24, 26, 30, 34, 36, 42, 48, 50, 58, 60. Key ncepts and Skills: definition
More informationChemical Bonding AP Chemistry Ms. Grobsky
Chemical Bonding AP Chemistry Ms. Grobsky What Determines the Type of Bonding in Any Substance? Why do Atoms Bond? The key to answering the first question are found in the electronic structure of the atoms
More informationCh 6 Chemical Bonding
Ch 6 Chemical Bonding What you should learn in this section (objectives): Define chemical bond Explain why most atoms form chemical bonds Describe ionic and covalent bonding Explain why most chemical bonding
More informationChapter 9: Chemical Bonding I: Lewis Theory. Lewis Theory: An Overview
Chapter 9: Chemical Bonding I: Lewis Theory Dr. Chris Kozak Memorial University of ewfoundland, Canada Lewis Theory: An verview Valence e - play a fundamental role in chemical bonding. e - transfer leads
More informationLecture 17 - Covalent Bonding. Lecture 17 - VSEPR and Molecular Shape. Lecture 17 - Introduction. Lecture 17 - VSEPR and Molecular Shape
Chem 103, Section F0F Unit VI - Compounds Part II: Covalent Compounds Lecture 17 Using the Valence-Shell Electron-Pair Repulsion (VSEPR) Theory to predict molecular shapes Molecular shape and polarity
More informationMolecular Geometry and Chemical Bonding Theory
Molecular Geometry and Chemical Bonding Theory The Valence -Shell Electron -Pair Repulsion (VSEPR) Model predicts the shapes of the molecules and ions by assuming that the valence shell electron pairs
More informationGroup 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8. Na Mg Al Si P S Cl Ar
CHM 111 Chapters 7 and 8 Worksheet and Study Guide Purpose: This is a guide for your as you work through the chapter. The major topics are provided so that you can write notes on each topic and work the
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 13: Phenomena
Chapter 13: Phenomena Phenomena: Scientists measured the bond angles of some common molecules. In the pictures below each line represents a bond that contains 2 electrons. If multiple lines are drawn together
More information8.1 Types of Chemical Bonds List and define three types of bonding. chapter 8 Bonding General Concepts.notebook. September 10, 2015
chapter 8 Bonding General Concepts.notebook Chapter 8: Bonding: General Concepts Mar 13 11:15 AM 8.1 Types of Chemical Bonds List and define three types of bonding. Bonds are forces that hold groups of
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 informationQuiz 5 R = lit-atm/mol-k 1 (25) R = J/mol-K 2 (25) 3 (25) c = X 10 8 m/s 4 (25)
ADVANCED INORGANIC CHEMISTRY QUIZ 5 and FINAL December 18, 2012 INSTRUCTIONS: PRINT YOUR NAME > NAME. QUIZ 5 : Work 4 of 1-5 (The lowest problem will be dropped) FINAL: #6 (10 points ) Work 6 of 7 to 14
More informationChemistry 121: Topic 4 - Chemical Bonding Topic 4: Chemical Bonding
Topic 4: Chemical Bonding 4.0 Ionic and covalent bonds; Properties of covalent and ionic compounds 4.1 Lewis structures, the octet rule. 4.2 Molecular geometry: the VSEPR approach. Molecular polarity.
More informationCHEMISTRY. Chapter 10 Theories of Bonding and Structure. The Molecular Nature of Matter. Jespersen Brady Hyslop SIXTH EDITION
CHEMISTRY The Molecular Nature of Matter SIXTH EDITION Jespersen Brady Hyslop Chapter 10 Theories of Bonding and Structure Copyright 2012 by John Wiley & Sons, Inc. Molecular Structures Molecules containing
More informationC H E M 1 CHEM 101-GENERAL CHEMISTRY CHAPTER 7 CHEMICAL BONDING & MOLECULAR STRUCTURE INSTR : FİLİZ ALSHANABLEH
C H E M 1 CHEM 101-GENERAL CHEMISTRY CHAPTER 7 CHEMICAL BONDING & MOLECULAR STRUCTURE 0 1 INSTR : FİLİZ ALSHANABLEH CHAPTER 7 CHEMICAL BONDING & MOLECULAR STRUCTURE The Ionic Bond Formation of Ions The
More information1. KCl.MgCl 2 .6H 2. Oisa. a) Mixed salt. c) Basic salt d) Complex salt
COORDINATION COMPOUNDS 1. KCl.MgCl 2.6H 2 Oisa a) Mixed salt b) Double salt c) Basic salt d) Complex salt 2. (NH 4 ) 2 SO 4 FeSO 4 6H 2 Ois a) Mohr s salt b) Alum c) Blue vitriol d) Simple salt 3.The number
More informationCHAPTER 3 CHEMICAL BONDING NUR FATHIN SUHANA BT AYOB SMK SULTAN ISMAIL, JB
CHAPTER 3 CHEMICAL BONDING NUR FATHIN SUHANA BT AYOB SMK SULTAN ISMAIL, JB LEARNING OUTCOMES (ionic bonding) 1. Describe ionic (electrovalent) bonding such as NaCl and MgCl 2 LEARNING OUTCOMES (metallic
More informationShapes of Molecules and Hybridization
Shapes of Molecules and Hybridization A. Molecular Geometry Lewis structures provide us with the number and types of bonds around a central atom, as well as any NB electron pairs. They do not tell us the
More informationReview questions CHAPTER 5. Practice exercises 5.1 F F 5.3
CHAPTER 5 Practice exercises 5.1 S 5.3 5.5 Ethane is symmetrical, so does not have a dipole moment. However, ethanol has a polar H group at one end and so has a dipole moment. 5.7 xygen has the valence
More informationH-H bond length Two e s shared by two Hs: covalent bonding. Coulomb attraction: Stronger attraction for e Fractional charge A dipole
8 Bonding: General Concepts Types of chemical bonds Covalent bonding Ex. 2 E (kj/mol) Repulsions of nucleus and e s r 0 458 0.074 r (nm) Zero interaction at long distance - bond length Two e s shared by
More informationChapters 8 and 9. Octet Rule Breakers Shapes
Chapters 8 and 9 Octet Rule Breakers Shapes Bond Energies Bond Energy (review): The energy needed to break one mole of covalent bonds in the gas phase Breaking bonds consumes energy; forming bonds releases
More informationCh. 9 NOTES ~ Chemical Bonding NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics.
Ch. 9 NOTES ~ Chemical Bonding NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. I. Review: Comparison of ionic and molecular compounds Molecular compounds Ionic
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 informationChemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 1
Chemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. How to get the book of
More informationHybridization of Orbitals
Hybridization of Orbitals Structure & Properties of Matter 1 Atomic Orbitals and Bonding Previously: Electron configurations Lewis structures Bonding Shapes of molecules Now: How do atoms form covalent
More information