Lecture 1: Chemistry of the Carbonyl Group
|
|
- Austen Francis
- 6 years ago
- Views:
Transcription
1 Lecture 1: Chemistry of the Carbonyl Group bjectives: By the end of this lecture you will be able to: 1. identify and name all major carbonyl functional groups; 2. use a molecular orbital approach to describe and account for the structure of a carbonyl group; 3. account for the electrophilicity of a carbonyl group. Important Carbonyl Compounds There are many types of carbonyl group. They are named according to their substitution patterns either side of the C= group. As we shall see later, they can be formed by oxidising alcohols. Secondary alcohols are oxidised to ketones; further oxidation - without breaking a C C bond - is not possible. Primary alcohols can be oxidised to aldehydes, which are at the same oxidation level as a ketone. However the presence of a hydrogen substituent means that further oxidation to a carboxylic acid is also possible. oxidation H H oxidation H ' H oxidation '
2 Carboxylic Acid Derivatives H N ' amidation ' NH 2 cat. H ' Cl ' H esterification ' H ' carboxylic acid cat. H Cl S Cl Cl Cyclic Esters and Amides N H (cyclic amide) (cyclic ester) Treating a Carboxylic Acid with Base H Base Na carboxylic acid e.g. NaH C 2 H NaH C 2 Na H 2
3 Structure of the Carbonyl Group using a Molecular rbital Approach Why does carbon always form four bonds and not two? Consider the ground state electron configuration of a carbon atom: To form a covalent bond requires the overlap of two orbitals each containing an unpaired electron. In its ground state, carbon has two unpaired electrons in two 2p atomic orbitals (As); thus in this state, it can form two covalent bonds. We can improve matters by taking the 2s and two of the 2p As and forming three sp 2 -hybridised atomic orbitals (HAs) which all have the same energy. ne 2p A is remaining. This so-called hybridisation requires energy. However, as orbitals of the same energy are filled singly first before pairing, even in this state we can still only form two covalent bonds as we still only have two unpaired electrons. If we provide additional energy that promotes one of the electrons out of an sp 2 -HA and into the 2p A then we now have a valence state in which we have four orbitals (three sp 2 HAs and one 2p A) that are all singly occupied. We can now form four covalent bonds. The energy required to form this valence state is more than compensated for by forming these two extra covalent bonds.
4 We can rationalise the structure of a carbonyl group by assuming the carbon and oxygen atoms making up the carbonyl group are both sp 2 -hybridised. Using this orbital approach, the carbon atom has three sp 2 -hybridised atomic orbitals (HAs) that are used to form three σ-bonds, and one p atomic orbital (A) to form a π-bond; likewise for the oxygen atom, only two of the sp 2 HAs are already filled with two electrons (remember oxygen has six electrons in its valence shell) and therefore do not form bonds, these are lone pairs. The p A on both atoms is orthogonal (i.e. at 90 ) to the plane containing the three sp 2 -HAs. The bonding structure of a carbonyl group can therefore be divided into its two constituent parts: the σ -framework (made from overlapping sp 2 -HAs) and the π-framework (made from overlapping p As). We shall consider each in turn and take acetaldehyde as an example: σ-framework: Formation of a σ-bond requires the direct overlap of two atomic or hybridised atomic orbitals. The C σ-bond is therefore formed by the direct overlap of one sp 2 -HA from carbon and one sp 2 - HA from oxygen. When these two HAs overlap (mix) they generate two new molecular orbitals (Ms) (Conservation of rbitals). This can be represented pictorially in a molecular orbital energy diagram:
5 There is one electron in each overlapping HA so the two new Ms are filled with the two electrons from these overlapping HAs. The lowest energy orbital is filled first (Hund's rule). Two electrons are required to fill an orbital (A, HA or M). Thus with only two electrons the lower lying σ-m (known as the bonding M) is completely filled, whilst the higher energy σ*-m (known as the antibonding M) remains empty. The effect of two singly occupied orbitals overlapping is to generate a system that is overall lower in energy - this is why a bond forms. Shape of σ- and σ*-ms:
6 The two remaining sp 2 -HAs on the carbon form similar σ-bonds to the atoms either side (i.e. the adjacent carbon and hydrogen atoms in the case of acetaldehyde). The two remaining sp 2 -HAs on the oxygen are each filled with two electrons (lone pairs). All the sp 2 -HAs and associated Ms are coplanar. The bond angle between any three atoms is approximately 120 π-framework: The p As on the carbon and oxygen are parallel to one another and orthogonal to the plane containing the σ-bonds. They too can overlap to form a bond. This is lateral overlap and results in the formation of a (weaker) π-bond. As before, two overlapping p As must form two Ms. The lower energy π-m is bonding, the higher energy π*-m is antibonding.
7 Shape of π- and π*-ms: NTE: there is zero probability of the electrons in the π-m existing in the plane containing the σ-bonding framework (this is known as a nodal plane). The electron density in the π-bond therefore lies above and below the plane containing the σ-bonds. The p As that form the C π-bond are higher in energy than the sp 2 -HAs that form the C σ-bond. Furthermore since π-ms are formed by lateral overlap of orbitals whereas σ-ms are formed by direct overlap, the net energy gain in bonding is lower when a π-bond is formed than when a σ-bond is formed. Consequently the resultant π-m is higher in energy that the σ-m. Just as there is a greater loss of energy in forming a σ-bond, the accompanying σ*-m is more 'antibonding' (higher in energy) than a π*-m and is therefore shifted to higher energy. This is best seen by overlaying the two molecular orbital energy diagrams:
8 E σ* π* C p A p A C sp 2 HA π sp 2 HA σ The Highest ccupied Molecular rbital (HM) is therefore the π (C=) -Molecular rbital. The Lowest Unoccupied Molecular rbital (LUM) is the π* (C=) -Molecular rbital. Polarisation of the C= Bond. Electronegativity of oxygen on the Pauling Scale = 3.44 Electronegativity of carbon on the Pauling Scale = 2.55 Consequently in the π-m (and the σ-m for that matter), there is more electron density on the oxygen than on the carbon. The bond is said to be polarised. Polarisation of the bond means that there is an uneven distribution of electron density between the two atoms leading to the build up of positive charge on the carbon end of the functional group with concomitant build up of negative charge on the oxygen end of the functional group.
9 Consequences of a Polarised Bond. 1. The carbonyl group exhibits a strong dipole moment. This has the effect of making the C= stretching band in I spectra very intense (see next lecture). 2. Although the C= bond is primarily a covalent bond, it also has some ionic character i.e. the atoms are also held together by electrostatic interactions. The net result is to make the C= group a thermodynamically more stable functional group than a C=C double bond. The formation of a C= group is a common thermodynamic driving force in chemical reactions. The C bond distance in a carbonyl group is 1.22 Å and shorter than the C C bond distance in a C=C double bond (1.32 Å).
10 3. CABNYL GUPS AE ELECTPHILIC i.e. they are susceptible to attack by NUCLEPHILES (species that contain high electron density). Since we know that the carbon atom has a δ+ charge on it and the oxygen a δ- charge, electron-rich nucleophiles will be attracted to the carbon atom and repelled by the oxygen atom on simple electrostatic grounds. NUCLEPHILES EACT WITH CABNYL CMPUNDS AT THE CABN CENTE Summary In this introductory lecture we have seen that there are a wide range of different functional groups containing a C= bond. There are many more! They all differ in the substituents either side of the C= group. These substituents have an important effect on the electrophilicity of the C= group (see later). We have also seen how a simple molecular orbital approach can be used to describe the planar structure of carbonyl compounds. The high electronegativity of oxygen compared to carbon means that the molecular orbitals that we derived by overlapping sp 2 -HAs (σ-ms) and p As (π-ms) are distorted such that more electron density lies on the oxygen end of the bond. Whilst both σ (C ) and π (C=) Ms are affected by this polarisation effect, the ramifications of this on the reactivity of carbonyl groups are most felt in the π-m system since this is where the HM and LUM are found.
Nucleophilic Addition Reactions of Carboxylic Acid Derivatives
Lecture 5: bjectives: Nucleophilic Addition eactions of Carboxylic Acid Derivatives By the end of this lecture you will be able to: draw the mechanism of a nucleophilic addition-elimination reaction with
More informationAldehydes and Ketones
Reading Chapter 12: 12.1-12.3, 12.6-12.9 Practice problems: in text problems and 19, 21-24, 28 Carbonyl Compounds II: Reactions of More Reactions of Carboxylic Acid Derivatives The Structure of 1 The Structure
More informationCovalent Bonds & Shapes of Molecules
ovalent Bonds & Shapes of Molecules hapter 1 1 rganic hemistry The study of the compounds of carbon. ver 10 million compounds have been identified. About 1000 new ones are identified each day! is a small
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 informationUnit 6: Molecular Geometry
Unit 6: Molecular Geometry Molecular Geometry [6-5] the polarity of each bond, along with the geometry of the molecule determines Molecular Polarity. To predict the geometries of more complicated molecules,
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 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 informationWilliam H. Brown & Christopher S. Foote
William. Brown & Christopher S. Foote Requests for permission to make copies of any part of the work should be mailed to:permissions Department, arcourt Brace & Company, 6277 Sea arbor Drive, rlando, Florida
More informationFor more info visit Chemical bond is the attractive force which holds various constituents together in a molecule.
Chemical bond:- Chemical bond is the attractive force which holds various constituents together in a molecule. There are three types of chemical bonds: Ionic Bond, Covalent Bond, Coordinate Bond. Octet
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 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 informationPeriodic Trends. Homework: Lewis Theory. Elements of his theory:
Periodic Trends There are various trends on the periodic table that need to be understood to explain chemical bonding. These include: Atomic/Ionic Radius Ionization Energy Electronegativity Electron Affinity
More informationLesmahagow High School CfE Advanced Higher Chemistry. Unit 2 Organic Chemistry and Instrumental Analysis. Molecular Orbitals and Structure
Lesmahagow High School CfE Advanced Higher Chemistry Unit 2 Organic Chemistry and Instrumental Analysis Molecular Orbitals and Structure 1 Molecular Orbitals Orbitals can be used to explain the bonding
More 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 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 informationChemistry 1A Spring 1998 Exam #4 KEY Chapters 9 & 10
Chemistry 1A Spring 1998 Exam #4 KEY Chapters 9 & 10 For each of the following, write the word, words, or number in each blank that best completes each sentence. (2 points each) 1. A(n) molecular orbital
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 Geometry and intermolecular forces. Unit 4 Chapter 9 and 11.2
1 Molecular Geometry and intermolecular forces Unit 4 Chapter 9 and 11.2 2 Unit 4.1 Chapter 9.1-9.3 3 Review of bonding Ionic compound (metal/nonmetal) creates a lattice Formula doesn t tell the exact
More informationCarbon Compounds. Chemical Bonding Part 2
Carbon Compounds Chemical Bonding Part 2 Introduction to Functional Groups: Alkanes! Alkanes Compounds that contain only carbons and hydrogens, with no double or triple bonds.! Alkyl Groups A part of a
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 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 informationStructure Determination. How to determine what compound that you have? One way to determine compound is to get an elemental analysis
Structure Determination How to determine what compound that you have? ne way to determine compound is to get an elemental analysis -basically burn the compound to determine %C, %H, %, etc. from these percentages
More informationPOS Checklist: Lewis Dot Diagrams. Electronegativity. Atomic Theory and Valence Electrons. Gilbert Newton Lewis. Aug 20 12:38 PM.
Chem 20 Unit A Bonding Lewis Dot Diagrams and Electronegativity You will... PS Checklist: use electron dot diagrams to support and explain ionic bonding theory. draw electron dot diagrams. define the term
More informationEssential Organic Chemistry. Chapter 1
Essential Organic Chemistry Paula Yurkanis Bruice Chapter 1 Electronic Structure and Covalent Bonding Periodic Table of the Elements 1.1 The Structure of an Atom Atoms have an internal structure consisting
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 informationORGANIC - EGE 5E CH. 2 - COVALENT BONDING AND CHEMICAL REACTIVITY
!! www.clutchprep.com CONCEPT: HYBRID ORBITAL THEORY The Aufbau Principle states that electrons fill orbitals in order of increasing energy. If carbon has only two unfilled orbitals, why does it like to
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 informationPolarity in Molecules!
Chapter 9 part 2: Polarity in Molecules, Valence Bond Theory! Read:!!BLB 9.3 5! W:!!BLB 9.33, 35, 38!!!Packet 9:8-11! Know:! bond angles and geometry! polarity of molecules! Polarity in Molecules! " Just
More informationSMK SULTAN ISMAIL JB, NUR FATHIN SUHANA BT AYOB
SMK SULTAN ISMAIL JB, NUR FATHIN SUHANA BT AYOB POLAR AND NON POLAR BONDS BOND POLARITY 1. Atoms with different electronegative from polar bonds (difference in EN) 2. Depicted as polar arrow : 3. Example
More informationStructure and Bonding of Organic Molecules
Chem 220 Notes Page 1 Structure and Bonding of Organic Molecules I. Types of Chemical Bonds A. Why do atoms forms bonds? Atoms want to have the same number of electrons as the nearest noble gas atom (noble
More informationChemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals
Chemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 10 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 Valence shell electron
More informationTHE CHEMISTRY OF THE CARBONYL GROUP
TE CEMISTY F TE CABYL GUP Professor Tim Donohoe 8 lectures, T, weeks 1-4, 2007 andout A C C You will be able to download copies of the handouts from this course at http://users.ox.ac.uk/~magd1571/teaching/teaching.htm
More informationCHEMISTRY XL-14A CHEMICAL BONDS
CHEMISTRY XL-14A CHEMICAL BONDS July 16, 2011 Robert Iafe Office Hours 2 July 18-July 22 Monday: 2:00pm in Room MS-B 3114 Tuesday-Thursday: 3:00pm in Room MS-B 3114 Chapter 2 Overview 3 Ionic Bonds Covalent
More informationDefinition: An Ionic bond is the electrostatic force of attraction between oppositely charged ions formed by electron transfer.
3 Bonding Definition An Ionic bond is the electrostatic force of attraction between oppositely charged ions formed by electron transfer. Metal atoms lose electrons to form +ve ions. on-metal atoms gain
More informationEarth Solid Earth Rocks Minerals Atoms. How to make a mineral from the start of atoms?
Earth Solid Earth Rocks Minerals Atoms How to make a mineral from the start of atoms? Formation of ions Ions excess or deficit of electrons relative to protons Anions net negative charge Cations net
More information: Bond Order = 1.5 CHAPTER 5. Practice Questions
CAPTER 5 Practice Questions 5.1 5.3 S 5.5 Ethane is symmetrical, so does not have a dipole moment. owever, ethanol has a polar group at one end and so has a dipole moment. 5.7 xygen has the valence electron
More informationChemical Bonding Petrucci, Harwood and Herring: Chapters 10 and 11
Chemical Bonding Petrucci, Harwood and Herring: Chapters 10 and 11 Aims: To look at bonding and possible shapes of molecules We will mainly do this through Lewis structures To look at ionic and covalent
More informationChemical Bonding. The Octet Rule
Chemical Bonding There are basically two types of chemical bonds: 1. Covalent bonds electrons are shared by more than one nucleus 2. Ionic bonds electrostatic attraction between ions creates chemical bond
More informationMULTIPLE CHOICE 2 points each
Name: Date: Score: / 110 Chapter 1/ TEST 1 OPEN BOOK KEY Organic Chemistry MULTIPLE CHOICE 2 points each 1. An atom of which element would have an electron configuration of 1s 2 2s 2 2p 6 3s 2 3p 1? a.
More informationElectrons and Molecular Forces
Electrons and Molecular Forces Chemistry 30 Ms. Hayduk Electron Configuration Atomic Structure Atomic Number Number of protons in the nucleus Defines the element Used to organize the periodic table 1 Bohr
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 information2/28/2011. Chapter 6 An Overview of Organic Reactions. Organic Chemical Reactions. 6.1 Kinds of Organic Reactions
John E. McMurry http://www.cengage.com/chemistry/mcmurry Chapter 6 An Overview of Organic Reactions CHP 6 Problems: 6.1-13, 17-36. Richard Morrison University of Georgia, Athens Organic Chemical Reactions
More informationAtomic Structure and Bonding. Chapter 1 Organic Chemistry, 8 th Edition John McMurry
Atomic Structure and Bonding Chapter 1 Organic Chemistry, 8 th Edition John McMurry 1 Common Elements Groups First row Second row In most organic molecules carbon is combined with relatively few elements
More informationIts Bonding Time. Chemical Bonds CH 12
Its Bonding Time Chemical Bonds CH 12 What is a chemical bond? Octet Rule: Chemical compounds tend to form so that each atom, by gaining, losing, or sharing electrons, has an octet of electrons in its
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 informationMaking Sugars. Carbon Dioxide. Properties of Carbon Dioxide
Making Sugars The reactions that take carbon dioxide to sugar involve nucleophilic attack at the carbon of carbon dioxide and reduction. The reducing equivalents come from NADPH. Energy is transmitted
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 informationCarbon and Its Compounds
Chapter 1 Carbon and Its Compounds Copyright 2018 by Nelson Education Limited 1 1.2 Organic Molecules from the Inside Out I: The Modelling of Atoms Copyright 2018 by Nelson Education Limited 2 s orbitals:
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 informationOrganic Chemistry. Introduction to Organic Molecules and Functional Groups
For updated version, please click on http://ocw.ump.edu.my Organic Chemistry Introduction to Organic Molecules and Functional Groups by Dr. Seema Zareen & Dr. Izan Izwan Misnon Faculty Industrial Science
More informationOrganic Chemistry. 2 nd Stage Pharmacy/ Undergraduate
Organic Chemistry 2 nd Stage Pharmacy/ Undergraduate Time of Lectures: Saturday; 8:30-11:30 am Instructor: Wrya O. Karim University email: wrya.karim@univsul.edu.iq Personal email: wrya.othman49@gmail.com
More informationMolecular Geometry: VSEPR model stand for valence-shell electron-pair repulsion and predicts the 3D shape of molecules that are formed in bonding.
Molecular Geometry: VSEPR model stand for valence-shell electron-pair repulsion and predicts the 3D shape of molecules that are formed in bonding. Sigma and Pi Bonds: All single bonds are sigma(σ), that
More informationFind the difference in electronegativity between the hydrogen and chlorine atoms
Answers Questions 16.2 Molecular polarity 1. Write a dot diagram for the HCl molecule. Find the difference in electronegativity between the hydrogen and chlorine atoms Difference in electronegativity =
More informationwith the larger dimerization energy also exhibits the larger structural changes.
A7. Looking at the image and table provided below, it is apparent that the monomer and dimer are structurally almost identical. Although angular and dihedral data were not included, these data are also
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 informationAcid-Base -Bronsted-Lowry model: -Lewis model: -The more equilibrium lies to the right = More [H 3 O + ] = Higher K a = Lower pk a = Stronger acid
Revision Hybridisation -The valence electrons of a Carbon atom sit in 1s 2 2s 2 2p 2 orbitals that are different in energy. It has 2 x 2s electrons + 2 x 2p electrons are available to form 4 covalent bonds.
More informationDr. Mohamed El-Newehy
By Dr. Mohamed El-Newehy Chemistry Department, College of Science, King Saud University http://fac.ksu.edu.sa/melnewehy Aldehydes and Ketones 1 Structure of Aldehydes and Ketones - Aldehydes and ketones
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 information13 Bonding: General Concepts. Types of chemical bonds. Covalent bonding Ex. H 2. Repulsions of nuclei and e s. Zero interaction at long distance
13 Bonding: General Concepts Types of chemical bonds Covalent bonding Ex. 2 E (kj/mol) epulsions of nuclei and e s r 0 458 0.074 r (nm) - bond length Two e s shared by two s: covalent bonding Zero interaction
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 informationTOPIC 4 ANSWERS & MARK SCHEMES QUESTIONSHEET 1 IONIC BONDING
TOPIC 4 ANSWERS & MARK SCEMES QUESTIONSEET 1 IONIC BONDING a) A bond formed by the complete transfer of one or more electrons from one atom to another to form ions of opposite charge which attract each
More informationChapter 10 Chemical Bonding II: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory
10.1 Artificial Sweeteners: Fooled by Molecular Shape 425 10.2 VSEPR Theory: The Five Basic Shapes 426 10.3 VSEPR Theory: The Effect of Lone Pairs 430 10.4 VSEPR Theory: Predicting Molecular Geometries
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 informationKetones and Aldehydes Reading Study Problems Key Concepts and Skills Lecture Topics: Structure of Ketones and Aldehydes Structure:
Ketones and Aldehydes Reading: Wade chapter 18, sections 18-1- 18-21 Study Problems: 18-43, 18-44,18-50, 18-51, 18-52, 18-59, 18-60, 18-62, 18-64, 18-72. Key Concepts and Skills: Interpret the IR, NMR,
More informationLecture Notes Chem 51C S. King. Chapter 20 Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation & Reduction
Lecture Notes Chem 51C S. King Chapter 20 Introduction to Carbonyl Chemistry; rganometallic Reagents; xidation & Reduction I. The Reactivity of Carbonyl Compounds The carbonyl group is an extremely important
More informationMolecular Orbital Theory. Molecular Orbital Theory: Electrons are located in the molecule, not held in discrete regions between two bonded atoms
Molecular Orbital Theory Valence Bond Theory: Electrons are located in discrete pairs between specific atoms Molecular Orbital Theory: Electrons are located in the molecule, not held in discrete regions
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 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 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 informationStructure and Reactivity: Prerequired Knowledge
Structure and eactivity: Prerequired Knowledge!!! The concepts presented in this summary are required for lecture and examination!!! 1. Important Principles in rganic Chemistry In general, structures which
More information3. Orbitals and hybridization.
Grossman, E 230 3. Orbitals and hybridization. 3.1 Atomic and Molecular Orbitals. We can use molecular orbital (MO) theory to describe the structure of molecules in more detail. MO theory also provides
More informationIonic Versus Covalent Bonding
Ionic Versus Covalent Bonding Ionic compounds are formed when electrons are transferred from one atom to another The transfer of electrons forms ions Each ion is isoelectronic with a noble gas Electrostatic
More informationLecture 3: Aldehydes and ketones
Lecture 3: Aldehydes and ketones I want to start by talking about the mechanism of hydroboration/ oxidation, which is a way to get alcohols from alkenes. This gives the anti-markovnikov product, primarily
More informationUNIT TWO BOOKLET 1. Molecular Orbitals and Hybridisation
DUNCANRIG SECONDARY ADVANCED HIGHER CHEMISTRY UNIT TWO BOOKLET 1 Molecular Orbitals and Hybridisation In the inorganic unit we learned about atomic orbitals and how they could be used to write the electron
More informationPolarity main concepts
POLARITY Polarity main concepts A polar molecule has opposite charged ends (+ & -) The polarity of a bond is the result of a difference in electronegativity between the two bonded atoms A molecule can
More information3/30/2015. Third energy level. Second energy level. Energy absorbed. First energy level. Atomic nucleus. Energy released (as light)
Chapter 2 An Introduction Chemistry Lecture 2: Energy Levels and Chemical Bonding Electrons are always moving Outside the nucleus in atomic orbitals Maybe usually Average distance from nucleus (size of
More informationChapter 8: Bonding. Section 8.1: Lewis Dot Symbols
Chapter 8: Bonding Section 8.1: Lewis Dot Symbols The Lewis electron dot symbol is named after Gilbert Lewis. In the Lewis dot symbol, the element symbol represents the nucleus and the inner electrons.
More informationThe wavefunction that describes a bonding pair of electrons:
4.2. Molecular Properties from VB Theory a) Bonding and Bond distances The wavefunction that describes a bonding pair of electrons: Ψ b = a(h 1 ) + b(h 2 ) where h 1 and h 2 are HAOs on adjacent atoms
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 informationCartoon courtesy of NearingZero.net. Chemical Bonding and Molecular Structure
Cartoon courtesy of NearingZero.net Chemical Bonding and Molecular Structure Chemical Bonds Forces that hold groups of atoms together and make them function as a unit. 3 Major Types: Ionic bonds transfer
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 informationValence Bond Theory Considers the interaction of separate atoms brought together as they form a molecule. Lewis structures Resonance considerations
CHEM 511 chapter 2 page 1 of 11 Chapter 2 Molecular Structure and Bonding Read the section on Lewis dot structures, we will not cover this in class. If you have problems, seek out a general chemistry text.
More 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 informationChapter 9. Chemical Bonding I: The Lewis Model. HIV-Protease. Lecture Presentation
Lecture Presentation Chapter 9 Chemical Bonding I: The Lewis Model HIV-Protease HIV-protease is a protein synthesized by the human immunodeficiency virus (HIV). This particular protein is crucial to the
More informationOrganic Chemistry 6 th Edition Paula Yurkanis Bruice. Chapter 1. Electronic Structure and Bonding. Acids and Bases Pearson Education, Inc.
Organic Chemistry 6 th Edition Paula Yurkanis Bruice Chapter 1 Electronic Structure and Bonding Acids and Bases 2011 Pearson Education, Inc. 1 Organic Chemistry Carbon-containing compounds were once considered
More informationWorksheet 5 - Chemical Bonding
Worksheet 5 - Chemical Bonding The concept of electron configurations allowed chemists to explain why chemical molecules are formed from the elements. In 1916 the American chemist Gilbert Lewis proposed
More informationOrganic Chemistry. Review Information for Unit 1. Atomic Structure MO Theory Chemical Bonds
Organic Chemistry Review Information for Unit 1 Atomic Structure MO Theory Chemical Bonds Atomic Structure Atoms are the smallest representative particle of an element. Three subatomic particles: protons
More informationChapter 10. VSEPR Model: Geometries
Chapter 10 Molecular Geometry VSEPR Model: Geometries Valence Shell Electron Pair Repulsion Theory Electron pairs repel and get as far apart as possible Example: Water Four electron pairs Farthest apart
More 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 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 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 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 informationPractice Hour Examination # 1-1
CHEM 346 Organic Chemistry I Fall 2013 Practice Hour Examination # 1-1 Solutions Key Page 1 of 12 CHEM 346 Organic Chemistry I (for Majors) Instructor: Paul J. Bracher Practice Hour Examination # 1-1 Monday,
More informationK + 09/04/2018. Structure of Organic Molecules. Ionic bond. The compound potassium fluoride consists of potassium (K+) ions and fluoride (F-) ions
Structure of rganic Molecules Ref. books: 1. A text book of rganic Chemistry - B.S. Bahl and Arun Bahl 2. rganic Chemistry - R.T. Morrison and R. N. Boyd Atom: The smallest part of an element that can
More informationCHAPTER 6: CHEMICAL NAMES AND FORMULAS CHAPTER 16: COVALENT BONDING
CHAPTER 6: CHEMICAL NAMES AND FORMULAS CHAPTER 16: COVALENT BONDING 6.1 Introduction to Chemical Bonding A chemical bond is a mutual electrical attraction between the nuclei and valence electrons of different
More information1. Which compound would you expect to have the lowest boiling point? A) NH 2 B) NH 2
MULTIPLE CICE QUESTINS Topic: Intermolecular forces 1. Which compound would you expect to have the lowest boiling point? A) N 2 B) N 2 C) N D) E) N Ans: : N 2 D Topic: Molecular geometry, dipole moment
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 informationMatter and Materials ATOMIC BONDS. Grade Sutherland high school Mrs. Harrison
Matter and Materials ATOMIC BONDS Grade 11 2018 Sutherland high school Mrs. Harrison 1. Chemical Bonds Why would atoms want to bond? Atoms are not generally found alone. They are found as components of
More informationDownloaded from
Points to Remember Class: XI Chapter Name: Chemical Bonding and Molecular Structure Top Concepts 1. The attractive force which holds together the constituent particles (atoms, ions or molecules) in chemical
More informationORGANIC - BROWN 8E CH CARBOXYLIC ACIDS.
RGANIC - BRWN 8E CH. 17 - CARBXYLIC ACIDS!! www.clutchprep.com RGANIC - BRWN 8E CH. 17 - CARBXYLIC ACIDS CNCEPT: CARBXYLIC ACID NMENCLATURE IUPAC: Replace alkane -e with Substituents are located using
More information