bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactions with electrophiles
Authors: Michael Hornby , Josephine Peach
Published: September 2023

This chapter reviews the addition of HX to C=C, the mechanisms of the reactions of HCI HBr, H2O addition to ethene and propene, carbocations, and cationic polymerization. It discusses the mechanism and stereochemistry of the addition of X2 and XY to C=C and addition to ethene and propene. It also examines the electrophilic aromatic substitution reactions, which includes aromatic compounds, halogenation, nitration, and acylation. The chapter highlights the crowding around the central carbon atom, wherein the larger C-C-C angle in the secondary carbocation keeps the other two carbon atoms further apart than they are in the primary carbocation. It talks about the electron-releasing inducive effect of two alkyl groups on the C+ that favours the secondary C+.
Reactions with radical intermediates
Authors: Michael Hornby , Josephine Peach
Published: September 2023

This chapter discusses the formation and nature of radicals, chain reactions, the use of fish-hook arrows, the halogenation of hydrocarbons, and the radical polymerization of alkenes. It looks at single bonds between two electronegative elements which are relatively weak, as the result of the interelectron repulsion between the nonbonded pairs of electrons on adjacent atoms. It also mentions chloroform (CHCl3), which was one of the first general anaesthetics to be discovered. Its usage has declined due to serious side-effects, and in fact anaesthetics used today are more effectiveand less toxic. The chapter highlights radical polymerization. This proceeds by addition of a radical to a multiple bond of the monomer. The chapter cites double bond that is retained in the polymer.
The Electronic Structure and Chemistry of Solids
Authors: Cox P. A.
Published: September 2023

The Electronic Structure and Chemistry of Solids shows how the electronic structures and properties of solids can be described in terms familiar to chemists. Recent years have seen a considerable growth of interest in chemical aspects of the electronic structure of solids. The first three chapters give a fairly elementary account of the topics. The later chapters present slightly more advanced aspects, including many topics of current research interest, such as metal-insulator transitions, low-dimensional solids and “molecular metals”, and the properties of surfaces. The discussion is illustrated by a wide variety of examples.
Spectroscopic methods
Authors: Cox P. A.
Published: September 2023

This chapter outlines a number of spectroscopic techniques, which provide the most direct source of information on the electronic energy levels of atoms, molecules, and solids. It describes optical absorption in the visible or ultraviolet (UV) range as a widely known type of electronic spectroscopy. It also explains how optical absorption peaks result from the transition of an electron from filled to empty orbitals or bands. The chapter talks about the absorption spectrum. This depends on both filled and empty bands, from which it is difficult to disentangle individual features of the separate levels. The chapter mentions methods using photons in the X-ray region or combining measurements of photon and electron energies that give more direct information about individual bands.
Elementary band theory
Authors: Cox P. A.
Published: September 2023

This chapter highlights the form of the crystal orbitals that make up the bands via the LCAO method, which is familiar to chemists from the theory of molecular orbitals. The chapter focuses on a crystal in which atoms form a regular array and electronic distribution is repeated from one cell unit to the next. It also introduces the idea of band theory through simple hypothetical models wherein atoms form arrays in one or two dimensions only. The chapter illustrates the form of crystal orbitals in three dimensions and analyses the consequences of the lattice periodicity. It discusses the approximate form of the wave function for an electron which moves along a row of atoms.
Lattice distortions
Authors: Cox P. A.
Published: September 2023

This chapter reviews band theory, which is concerned with the behaviour of electrons in a periodic solid and the arrangement of atoms in a crystal determined by the bonding interactions of the electrons. It mentions the Jahn-Teller effect, wherein electron configurations produce forces that distort the lattice from its ideal regular configuration. It also explains the presence of electrons causing a distortion which can destroy the simple periodicity of the lattice, disrupts the band structure, and has an important influence on the electronic properties of the solid. The chapter discusses distortions caused by electrons, which are important in two interesting areas of solid-state chemistry: low-dimensional solids and mixed-valency compounds. It examines the breakdown of crystal periodicity in certain situations, such as in cases where the solid has defects or has foreign impurity atoms.
Brillouin zones and the reciprocal lattice
Authors: Cox P. A.
Published: September 2023

In the LCAO approach to band theory, which is explained in Chapter 4, the first Brillouin zone (BZ) gives the range of wave vectors k necessary to generate all distinct Bloch sums of atomic orbitals, without any duplication. In the free-electron model, it...
Aromatic Heterocyclic Chemistry
Authors: Davies David T.
Published: September 2023

Aromatic Heterocyclic Chemistry argues that heterocyclic compounds are of prime importance to organic chemists working in the chemical industry. The emphasis of this text is on synthetic aspects rather than properties, and it covers the essential details and basic principles with reference to all the important classes of heterocyclic compounds. Instructional problems are included as an aid to comprehension, and references to more detailed texts are provided.
Oxazoles, imidazoles, and thiazoles
Authors: Davies David T.
Published: September 2023

This chapter examines oxazoles, imidazoles, and thiazoles. Oxazole, imidazole, and thiazole are the parent structures of a related series of 1,3-azoles containing a nitrogen atom plus a second heteroatom in a five-membered ring. They are isomeric with the 1,2-azoles isoxazole, pyrazole, and isothiazole, and their aromaticity derives from delocalization of a lone pair from the second heteroatom. Oxazole, imidazole, and thiazole can be formally derived from furan, pyrrole, and thiophene respectively by replacement of a CH group by a nitrogen atom at the 3 position. The presence of this pyridine-like nitrogen deactivates the 1,3-azoles towards electrophilic attack and increases their susceptibility towards nucleophilic attack. The chapter then looks at the synthesis, electrophilic substitution reactions, anion chemistry, and nucleophilic aromatic substitution of oxazoles, imidazoles, and thiazoles.
Isoxazoles, pyrazoles, and isothiazoles
Authors: Davies David T.
Published: September 2023

This chapter investigates isoxazoles, pyrazoles, and isothiazoles. Isoxazole, pyrazole, and isothiazole are the parent structures of the 1,2-azole family of heterocycles, having a nitrogen atom plus one other heteroatom in a 1,2-relationship in a five-membered ring. The aromatic sextet is completed by delocalization of the lone pair from the second heteroatom. Consequently, as in pyridine, the nitrogen atoms of the 1,2-azoles have a lone pair available for protonation. However, the 1,2-azoles are significantly less basic than the 1,3-azoles because of the electron-withdrawing effect of the adjacent heteroatom. Isoxazole and isothiazole are essentially non-basic heterocycles, and even pyrazole is a much weaker base than the corresponding 1,3-azole imidazole. As with substituted imidazoles, substituted pyrazoles may exist as a mixture of tautomers. The chapter then looks at the synthesis, electrophilic substitution, and anion chemistry of isoxazoles, pyrazoles, and isothiazoles.
Pyrimidines
Authors: Davies David T.
Published: September 2023

This chapter explores pyrimidines. Formal replacement of a CH unit in pyridine by a nitrogen atom leads to the series of three possible diazines: pyridazine, pyrimidine, and pyrazine. Like pyridine, they are fully aromatic heterocycles. The effect of an additional nitrogen atom as compared to pyridine accentuates the essential features of pyridine chemistry. Electrophilic substitution is difficult in simple unactivated diazines because of both extensive protonation under strongly acidic conditions and the inherent lack of reactivity of the free base. Nucleophilic displacements are comparatively easier. The most important of the diazines is pyrimidine. The actual biosynthesis of purines involves construction of a pyrimidine ring onto a pre-formed imidazole. The chapter then considers the synthesis and chemistry of the pyrimidine ring system.
Organic Synthesis
Authors: Thomas Susan E.
Published: September 2023

Organic Synthesis describes the properties and reactions of organoboranes and organosilanes, emphasizing how they can be used to provide simple solutions to a variety of synthetic problems. Compounds of boron and silicon are widely used in organic synthesis, and their study forms a core in many chemistry courses. Helpful study questions are provided at the end of each section, and the suggested further reading provides a useful guide to more advanced work in the field.
Oxidation and Reduction in Organic Synthesis
Authors: Donohoe Timothy J.
Published: September 2023

Oxidation and Reduction in Organic Synthesis looks in detail at the topic of organic synthesis. The manipulation of functional groups by oxidative or reductive processes is central to organic chemistry, the text argues. This book provides a clear summary of oxidative and reductive processes, emphasizing general principles and common factors, and shows the applications of these reactions in organic synthesis. After an initial introduction, chapters cover enaitioselective oxidation, oxidation reactions in synthesis, reduction reactions, and enaitioselective reduction.
Organometallic Reagents in Synthesis
Authors: Jenkins Paul R.
Published: September 2023

Organometallic Reagents in Synthesis looks at the properties and reactions of main group organometallic compounds, placing particular emphasis on their applications in synthesis. The book adopts a logical approach to this area of organic chemistry, and provides an account of all aspects of the field. Study problems are included at chapter ends, along with suggestions for further reading on the topic.
Polar Rearrangements
Authors: Harwood Laurence M.
Published: September 2023

Polar Rearrangements brings together the general principles of polar rearrangements in this study. The text deals with all the major rearrangements involving electron-deficient atoms or charged intermediates. Reactions involving migration to electron-deficient carbon, nitrogen, oxygen, and sulphur, and sigmatropic rearrangements involving polar species, are thus examined. Clear discussions of the reaction mechanisms are followed by examples of synthetic applications, providing an account of the nature and importance of these processes.
Nucleophilic rearrangements to carbon involving carbanions and carbenes
Authors: Harwood Laurence M.
Published: September 2023

This chapter focuses on nucleophilic rearrangements, which have migrating species that are negatively charged and are sufficient for the migration terminus to possess a leaving group. It examines the electron deficiency at the migration terminus in another synthetically important group of nucleophilic rearrangements. This is provided by the generation of a valence with a satisfied and unsaturated carbene. It also describes the Wolff rearrangement as the most frequently encountered carbene-induced nucleophilic rearrangement. The chapter talks about dihalocarbenes as well. These have singlet ground states, while alkyl carbenes have triplet ground states. It discusses different electronic configurations of singlet and triplet carbenes that result in differences of reactivity of species in electrocyclic reactions.
Arynes
Authors: Moody Christopher J. , Whitham Gordon H.
Published: September 2023

This chapter describes arynes as neutral intermediates derived from aromatic rings by removing two substituents and leaving behind two electrons to be distributed between two orbitals. It highlights C6H4. This is based on benzene as the most common aryne, although aromatic and heteroaromatic systems can give similar species. The chapter also mentions that the need to postulate C6H4 started in the 1870s, which led to the formation of biphenyl in certain reactions. It was not until the 1940s that advanced clear and convincing arguments for the intermediacy of arynes were developed. The chapter analyzes ortho-Benzyne, which is usually represented as a singlet molecule with a carbon-carbon triple bond. It looks at theoretical calculations that support the view that the symmetrical triple bond structure is lowest in energy and suggests that the structure is distorted from benzene.
Polycyclic arenes
Authors: Sainsbury Malcolm
Published: September 2023

This chapter discusses polycyclic arenes. The fusion of benzene rings leads to an array of polycyclic arenes, of which naphthalene, anthracene, and phenanthrene are the best known. Other compounds in the series include chrysene, pyrene, tetracene, and coronene. Many polycyclic aromatic hydrocarbons are found in coal tar, and are formed when plant materials are partially combusted. Some are procarcinogens, that are oxidized within the body to the true cancer-promoting compounds. Very large polycyclic systems are known, and graphite consists of planes derived from an infinite linear fusion of benzene nuclei. Naphthalene is much more easily hydrogenated than benzene, but the reduction only proceeds as far as 1,2,3,4-tetrahydronaphthalene (tetralin). Meanwhile, anthracene can be synthesized in several ways, two of which parallel the constructions of naphthalenes.
Acids and bases
Authors: Hornby Michael , Peach Josephine
Published: September 2023

This chapter examines acids and bases. The Brønsted–Lowry theory states that acids are proton donors, and bases are proton acceptors. Acid/base reactions are largely equilibria and are therefore under thermodynamic control. Many organic acids, such as ethanoic acid, are weak acids. The equilibrium constants are small, much less than 1, and remarkably little of the acid donates its proton to water in aqueous solution. Moreover, many organic acids and bases are largely insoluble in water. The chapter then considers the reactivity of bases as leaving groups and nucleophiles, before comparing acid strengths and base strengths. It also looks at amino acids, which are the building blocks of proteins; they are compounds which have major structural and catalytic roles in all living organisms.
Quantum mechanics and light
Authors: Softley T. P.
Published: September 2023

This chapter provides a brief overview of quantum mechanics and light. It begins with a discussion on the purpose and practice of spectroscopy, which involves the investigation of the interaction of light with matter. It then breaks down the nature of electromagnetic radiation, expounding on the classical theory of light before turning to photons and how they make up light. Next, the chapter elaborates on the properties of lasers and how these same remarkable properties are achieved largely from the process of stimulated emission. Afterward, the chapter presents the wave mechanical description of an atom, and considers the Schrödinger equation and the Hamiltonian operator. Lastly, angular momentum is explored.
Types of macrocyclic ligand and their complexes
Authors: Constable Edwin C.
Published: September 2023

This chapter discusses some of the macrocycles which are commonly encountered in modern coordination chemistry. It outlines the different types of macrocyclic ligands and their complexes. These include polyamine or imine macrocycles; porphyrins and phthalocyanines; crown ethers; unusual donor atoms; mixed donor-atom macrocycles; cryptands and cavitands and encapsulating ligands; and dinucleating macrocycles and linked macrocyclic ligands. The chapter then looks at the concept of the hole-size of a macrocyclic ligand. The presence of a cavity surrounded by donor atoms is one of the key features of macrocyclic lingands. The chapter also considers what the consequences of hole size for coordination chemistry are.
Applications of Artificial Intelligence in Chemistry
Authors: M Hugh
Published: September 2023

Applications of Artificial Intelligence in Chemistry details the various applications of artificial intelligence in the chemical science fields. Artificial intelligence is not just about making machines think; it is also a powerful problem-solving tool. Many scientific problems can be solved only with difficulty using conventional methods, yet these same problems may be ideally suited to attack using artificial intelligence. The chapters cover artificial intelligence, artificial neural networks, expert systems, and genetic algorithms.
Computational Chemistry
Authors: Guy H. Grant , W. Graham Richards
Published: September 2023

Computational Chemistry starts by arguing that the uses of computers in chemistry are many and varied. This ranges from the modelling of solid state systems to the design of complex molecules which can be used as drugs. This text introduces the many methods currently used by practising computational chemists and shows the value of computers in modern chemical research. The text describes the various computational techniques available and explains how they can be applied to single molecules, to assemblies of molecules, and to molecules undergoing reaction. An introductory chapter outlines the hardware and software available, and looks at some applications and developments. Subsequent chapters cover quantum mechanics, molecular mechanics, statistical mechanics, the modelling of biomolecules, and drug design. Whilst emphasizing the use of computers to model biological systems, the chapters explain how the methods can be applied to a whole range of chemical problems.
Introduction
Authors: B.G. Cox
Published: September 2023

This chapter introduces two separate objects of chemical kinetics, which are the analysis of the mechanism by which a reaction occurs, and the determination of the absolute rate of the reaction or its individual steps. It explains that kinetics is concerned with the passage towards equilibrium, particularly with the details of the process whereby a system moves from one state to another, and with the time required for the transition. It also describes the routes to equilibrium, of which there are many. The rates of chemical transformations constitute a more intricate problem than equilibria. The chapter analyses chemical primary processes which include a transition between two atomic or molecular states separated by a potential barrier. It also mentions the time-range over processes of a variety of chemical compounds and reactions which occur in more than twelve orders of magnitude.
Fast reactions in solution
Authors: B.G. Cox
Published: September 2023

This chapter looks at classical kinetic studies of the rates and mechanisms of chemical reactions that normally permit the determination of the overall rate. This rate is constant for reaction and includes several equilibrium constants. The chapter cites the catalysis of reactions by acids and bases which frequently involve the coupling of extremely fast proton-transfer reactions with other processes. It also defines fast reactions as those with half-lives of less than one second, such as reactions that are too fast to be studied conveniently by conventional techniques. The chapter provides a summary of current important techniques for studying fast reactions, including the upper limit for chemical transformations which is set by the period of a molecular vibration. It discusses the steps of bimolecular reactions and covers the approach of the species, control by diffusion, and real chemical transformation.
Introductory theory
Authors: Harwood Laurence M. , Claridge Timothy D.W.
Published: September 2023

The chapter provides some background on the development of non-destructive spectroscopic methods of analysis which can be carried out on small amounts of materials. This has provided the fundamental thrust behind the progress of organic chemistry. It looks at the identification of unknown molecules of high complexity which carry out samples that range from several nanograms to a milligram of material. It also refers to techniques that are used routinely by organic chemists for structural analysis, such as ultraviolet (UV) spectroscopy, which came into general use during the 1930s. The chapter presents analytical techniques that involve the absorption of specific energies of electromagnetic radiation. These correspond exactly in energy to specific excitations within the molecule. It explores what we know of the transitions which may be induced by absorption of a certain wavelength of electromagnetic radiation. These can be used to infer structural features.
Nuclear magnetic resonance spectroscopy: the basics
Authors: Harwood Laurence M. , Claridge Timothy D.W.
Published: September 2023

This chapter describes nuclear magnetic resonance (NMR) spectroscopy as the most powerful and versatile of all analytical techniques used by organic chemists. It highlights the spectroscopic features of NMR spectroscopy, which correlate with individual atoms within a molecule rather than groups of atoms. It also emphasizes the possibility of determining the structures of small-to-medium-sized organic molecules in solution and focuses on solution spectroscopy as it is in this form of NMR that is the most useful in organic chemistry. The chapter explains that NMR occurs as a result of the fact that the nuclei of certain atoms possess spin, which is characterized by a quantum number and takes integer and half-integer values. It points out that nuclei with zero spin are not amenable to NMR observation, although most elements have at least one isotope that possess nuclear spin.
Nuclear magnetic resonance spectroscopy: further topics
Authors: Harwood Laurence M. , Claridge Timothy D.W.
Published: September 2023

This chapter analyses the power of modern pulse-Fourier to transform nuclear magnetic resonance (NMR). The chapter then shows a variety of techniques that assist in the interpretation of spectra and allows for the routine observation of nuclei other than protons. It reviews the original motivation for establishing pulse-Fourier transform methodologies which may be accumulated with a concomitant increase in signal-to-noise ratio for a given period of data collection. It also looks at the possibility of using more than one pulse prior to data acquisition. This controls the behaviour of nuclear spins. The chapter considers how an ensemble of nuclei behave and the processes that occur following pulse excitation of a sample. It uses a pictorial approach to show the vector model of NMR.
Enamines
Authors: Bailey Patrick D. , Morgan Keith M.
Published: September 2023

This chapter looks into imines. It enumerates the key features of imines: oxidation level two, susceptibility to nucleophilic attack on carbon, and easy protonation in relation to producing reactive iminium ions. Imines are prepared from the reaction of an aldehyde or a ketone with a primary amine. Thus, the reaction is driven primarily through the removal of water. Imine will be more stable than simple aliphatic imines if it is conjugated by an aromatic ring. The chapter discusses the reactions of imines through attack by carbon nucleophiles, the Vilsmeyer reaction, the Mannich reaction, reduction, and hydrolysis. Additionally, the chapter shows that the reduction to amines is readily achieved via hydrogenation of hydride reducing conditions.
N-Oxides
Authors: Bailey Patrick D. , Morgan Keith M.
Published: September 2023

This chapter focuses on oximes. It regards oximes as a simple way to make N-O-containing functional groups that undergo numerous important reactions. The chapter looks into the synthesis of oximes with the analogy of hydrazones. It considers the reactions of oximes such as hydrolysis, dehydration, the Beckmann rearrangement, and reduction. In terms of hydrolysis, oximes are referred to as relatively inert. Hydrogenation over highly active catalysts, on the other hand, leads to a reduction of α-bond and the N-O α-bond. The most important commercial use of the Beckmann rearrangement is the formation of α-caprolactam.
Rotational spectroscopy
Authors: Brown John M.
Published: September 2023

This chapter cites a gas phase sample that demonstrates molecules in continual motion, appropriate to its thermal energy. It describes the continual motion of the molecules as rotational energy, which is the kinetic energy associated with the tumbling motion of the molecules relative to an observer in the laboratory. The chapter explains that the transitions between individual rotational levels give rise to the rotational spectrum of the molecule and that the quantum states of a single molecule remain well-defined as long as the molecule is in isolation. However, the collision of a molecule with another species can change the rotational state. The definition of the spectrum is then in danger of being destroyed. It explains that the orientation of individuals in a solid state is usually fixed in space, and energy cannot be stored in the form of rotational motion, which is why rotational spectroscopy is carried out on gaseous samples at low pressure.
Raman spectroscopy
Authors: Brown John M.
Published: September 2023

This chapter discusses Raman spectroscopy, which is based on a light scattering effect and named after the Indian physicist C.V. Raman, who was the first to observe it after A. Smekal had theoretically predicted it in 1928. Raman spectroscopy provides a way for obtaining information on the rotational and vibrational levels of a homonuclear diatomic molecule, which is not possible using rotational and rotational–vibrational spectra. The chapter also mentions Rayleigh scattering wherein the great majority of photons are scattered in all directions without a change in energy. The chapter illustrates how a modern Raman spectrometer probes light from a monochromatic source directed at the molecular sample. The scattered light is then viewed at right angles to the incoming beam. Its component wavelength is resolved with either a monochromator or an interferometer.
Alkynyl-, vinyl-, and arylsilanes
Authors: Thomas Susan E.
Published: September 2023

This chapter studies the conversion of a terminal alkyne to its alkynylsilane. It displays how terminal alkynes are converted into alkynylsilanes by metallation and the addition of chlorosilane. The chapter also looks at the regioselective electrophilic attack on alkynylsilanes. It assesses how electrophiles react with alkynylsilanes at the silicon-bearing end of the alkyne. The chapter then moves to explore hydrosilylation and its application to the synthesis of vinylsilanes. It argues that the reaction is catalyssed by many transition-metal complexes — showing the mechanism for the hydrosilylation of an alkene under transition-metal catalysis. Finally, the chapter pays attention to how arylsilanes are prepared. It outlines the steps of the reaction, then shows how arylsilanes undergo a reaction with electrophiles known as ipso-desilylation.
Silyl enol ethers and related silyl ethers
Authors: Thomas Susan E.
Published: September 2023

This chapter focuses on related silyl ethers and silyl enol ethers. It defines silyl enol ethers as stable molecules which may be isolated, purified, and characterized using standard organic procedures. The chapter contends that they are sources of regiochemically-pure enolate ions and their equivalents, and as such, they play an important role in modern synthetic organic chemistry. The chapter then moves to explicate the formation of silyl enol ethers. It illustrates the deprotonation of an unsymmetrically substituted ketone such as 2-methylcyclohexanone, then explores the process of conjugate additions/silylation and hydrosilylation. The chapter discusses the reactions of silyl enol ethers, then elaborates on the silyl ketene acetals which are derived from ester enolates and are closely related to silyl enol ethers.
Transition metal oxides
Authors: Weller Mark T.
Published: September 2023

This chapter evaluates transition metal oxides, reviewing binary transition metal oxide structures. The structure of many binary oxides can be predicted on the basis of the relative sizes of the metal and oxide ions and filling of holes in a close peaked oxide lattice. Such predictions of structure are more difficult for ternary phases. The combination of two or more metals in an oxide generates a wealth of structural possibilities dependent on the relative sizes of the two metal ions and the oxide ion. In addition, the stoichiometry of the ternary oxide may be changed by varying the proportions of the two component oxides and, for transition and lanthanide elements, the oxidation state. The chapter then looks at the perovskite structure, insertion compounds, lithium niobate, the spinel structure, and the K2NiF4 structure.
Non-stoichiometry
Authors: Weller Mark T.
Published: September 2023

This chapter assesses non-stoichiometry. Non-stoichiometric materials are characterized by two criteria. From a thermodynamic standpoint, the free energy of the system depends upon both the composition and temperature. A more useful criterion, in that the behaviour is readily identified by experiment, is that the lattice parameter of the system varies smoothly as a function of composition. All crystalline materials contain a certain number of defects. The chapter then looks at two types of defect which are commonly found in ionic inorganic compounds: Schottky defects and Frenkel defects. It also considers four non-stoichiometric systems which illustrate the major ways in which large compositional variations can be incorporated into materials through defects and interstitials. Finally, the chapter discusses the elimination of defects through the process of crystallographic shear, before examining intercalation compounds.
Zeolites, intercalation in layer materials and solid electrolytes
Authors: Weller Mark T.
Published: September 2023

This chapter presents some widely studied inorganic materials which have significant applications and properties, including zeolites, intercalation in layer materials, and solid electrolytes. The zeolites are a group of compounds, many of which are naturally occurring minerals, named after their property of evolving water when heated. These materials are widely used for their ion exchange, absorption, and catalytic properties. The chapter then looks at two-dimensional intercalation chemistry, before considering fast ion conduction in solids. The diffusion of ions through solids is facilitated by the presence of suitable vacant sites to which a diffusing ion may migrate. In some materials, the presence of a large number of suitable sites within the structure for ion migration, even at low temperatures, allows facile diffusion of ions and these materials are known as fast ion conductors.
Polyatomic molecules
Authors: Richards W.G. , Scott P.R.
Published: September 2023

This chapter analyses the principles that explain the electronic structures of diatomic molecules and those carried across larger molecules. It reviews how molecular-orbitals can be constructed from linear combinations of atomic orbitals, wherein the total electronic wave function is antisymmetrized in order to take account of the Pauli principle. It also illustrates a molecular-orbital diagram that can be qualitatively corrected by using just the atomic orbitals that are occupied in separate atoms. The chapter looks at descriptions of molecular symmetry that can be formalized by using group theory, which is useful in describing the structures of complex molecules. It discusses the origin of the notation that is often used to describe molecular-orbitals and electronic states.
Energy levels in NMR
Authors: Richards W.G. , Scott P.R.
Published: September 2023

This chapter looks into nuclear magnetic resonance (NMR), which is considered the most important advance in molecular spectroscopy in the second half of the twentieth century. It talks about the technique that uses NMR and electronic spin resonance (ESR) spectroscopy together, which has had an impact on all areas of molecular science from chemistry to biochemistry and medicine. It also describes an atom with angular momentum that has a rotating charge and acts as a little magnet, being governed by the microscopic rules of quantum mechanics. The chapter explains the energy of the ground state of the hydrogen atom in a magnetic field, which provides a rich pattern of energy levels. It refers to the actual magnitudes of the energies of the transitions observed in magnetic resonance experiments, which depend on the strength of the applied magnetic field.
Bifunctional Compounds
Authors: Ward Robert S.
Published: September 2023

Bifunctional Compounds outlines some of the methods used to prepare bifunctional compounds and then surveys the chemistry of some of the more important classes. Most important organic molecules contain more than one functional group, and very often the interaction between these groups determines the chemical and biological behaviour of the compounds. Individual chapters look at the preparation of bifunctional compounds, reactions of dienes, of diols, of hydroxy- and aminocarbonyl compounds, of dicarbonyl compounds, and of unsaturated carbonyl compounds. The text also covers enamines, enol ethers, enolates, allyl compounds, and cyclization and polymerization.
Preparation of bifunctional compounds
Authors: Ward Robert S.
Published: September 2023

This chapter describes methods used to prepare bifunctional compounds, which are usually specific to the particular combination of functional groups. It explains the retro-synthetic analysis, which is an approach to the synthesis of 1,2-bifunctional compounds that considers as a possible precursor the alkene that would result from eliminating the two functional groups. The chapter also considers an alternative approach that involves imagining cleaving the bond which links the two functionalized carbon atoms. The chapter emphasizes that working backwards is a logical way to tackle the synthesis of a given target molecule as it leads to a selection of appropriate methods for bringing about forward transformation. It details the preparation of 1,2-diols by preparing hydroxylation of alkenes, reductive dimerization of ketones, or nucleophilic addition to α-hydroxycarbonyl compounds.
Reactions of hydroxy- and aminocarbonyl compounds
Authors: Ward Robert S.
Published: September 2023

This chapter examines hydroxyaldehydes and ketones that react intramolecularly to form cyclic hemiacetals. It highlights the production of five- or six-membered rings, wherein the cyclizationcyclisation becomes so facile that it occurs even under neutral conditions. It also talks about the equilibrium betweenSince the hydroxycarbonyl compound and the cyclic hemiacetalhemiciacetal are in a solution, compounds which do not formally display a carbonyl group that may undergo the reactions of a carbonyl compound. The chapter cites glucose as an example of a hydroxyaldehyde that exists mainly in the form of its hemiacetal, both in the solid state and in solution. It refers to the open chain aldehyde and the six-membered cyclic hemiacetal that are in equilibrium in solution, causing glucose to react as an aldehyde.
Cyclisation versus polymerisation
Authors: Ward Robert S.
Published: September 2023

This chapter reviews the competition between cyclization and polymerization and states that this can be influenced in several ways, such as through varying the concentration of the solution. It demonstrates a method that can be used to promote cyclization at the expense of polymerization, namely to carry out the reaction in dilute solution so that the probability of an intermolecular reaction taking place is reduced. It also talks about the entropy factor, a measure of the probability of the two ends of the chain coming into contact with one another. The chapter explains that the enthalpy factor can be correlated with the stability of the ring being produced and is most favourable for six-membered rings. It concludes that five- and six-membered rings are obtained easily by cyclization, while three- or four-membered rings are difficult to obtain through this method. The chapter goes on to discuss the preparation of non-aromatic carbocyclic compounds and non-aromatic heterocyclic compounds, as well as the polymerization of bifunctional compounds.
Organometallics 2
Authors: Bochmann Manfred
Published: September 2023

Organometallics 2 examines the interaction of transition metals with unsaturated molecules. This topic has led to fundamental insights in the nature of the chemical bond which, in turn, has provided the basis of important present-day applications such as transition metal mediated synthesis or homogeneous and heterogeneous catalysis. This book outlines the chemistry and discusses the bonding in of some of the most important classes of organometallic compounds: the complexes of transition metals with Pi-ligands such as alkenes, alkynes, arenes, and cyclopentadienyl and allyl ligands.
Molecular mechanisms and reaction rates
Authors: Maskill Howard
Published: September 2023

This chapter examines molecular mechanisms and reaction rates. The principal technique for the investigation of mechanisms of chemical reactions is chemical kinetics. It is really a group of techniques. Their common feature involves measurements of rates of reactions. The strategy in the elucidation of mechanisms is used to carry out exploratory investigations, produce a tentative mechanism, predict some consequences from the mechanism, then investigate those consequences. The initial evidence will be used for product analysis. A provisional mechanism which accounts for the products is then proposed from which a rate law can be predicted and investigated. At the stage when the rate law required by the mechanism is identical with that observed, then some confidence in the mechanism is justifiable. More stringent and subtle kinetics and product analysis tests may next be applied. The chapter studies simple transition state theory before considering the physical significance and mechanistic interpretation of activation parameters.
Process Development
Authors: Lee Stan , Robinson Graham
Published: September 2023

Process Development aims to bridge the gap between the laboratory synthesis of an organic compound and its industrial manufacture on a large scale. The text uses real examples to show the problems which may be encountered in scaling up chemical syntheses and the ways in which these problems may be overcome. The major part of the book is devoted to genuine case histories from ICI/Zeneca Pharmaceuticals. Through a range of carefully chosen examples, the book explains how it is possible to synthesize multi-kilogram quantities of a new organic compound which has previously been made in the laboratory only on the milligram scale. A range of aliphatic, aromatic, and heterocyclic compounds is covered.
Lanthanides to lone pair
Authors: Mingos D.M.P.
Published: September 2023

This chapter begins by studying lanthanides and lattice energy. Lanthanides, or rare earth metals, are those elements from cerium to lutetium. The lattice energy is the energy required to convert one mole of a solid ionic compound in its usual lattice structure at absolute zero into its gaseous ions. Theoretically, according to the ionic model, the calculated lattice energy is given by the Born–Landé equation. The chapter then looks at ligands, which are ions or neutral molecules which can form co-ordinate or dative bonds with metal centres. It also considers the ligand field theory and lone pair orbitals. The ligand field theory has been developed to describe the electronic spectra and the magnetic, thermochemical, and kinetic properties of transition metal complexes.
Applied photochemistry
Authors: Wayne Carol E. , Wayne Richard P.
Published: September 2023

This chapter explores some of the applications of photochemistry, ranging from photography to photomedicine. The making of a more or less permanent record of light and shade by photography represents the best-known of all applied photochemical processes. Photography is one of a series of photoimaging techniques in which photons are used for the capture and replication of image information. The chapter then looks at photochromism and photopolymerization. It also considers the solar energy storage; photochemistry in synthesis; lasers; and optical brighteners. Finally, the chapter studies photomedicine, discussing phototherapy, photochemotherapy, and how ultraviolet radiation is employed in the disinfection, sterilization, and purification of water.
Effects on conformation
Authors: Kirby A.J
Published: September 2023

This chapter examines the effects on conformation. The single most important principle of conformational analysis is that rotation about single bonds is not free, but restricted by energy barriers which depend on the substituents at the ends of each bond. Other things being equal, staggered conformations are preferred, with large, sterically demanding groups antiperiplanar, i.e. as far away from each other as possible. The general orbital interaction demonstrates that (four-electron) interactions between filled orbitals are antibonding, and thus repulsive. These repulsive interactions are largest in eclipsed conformations and minimized in staggered conformations. It is often convenient to discuss torsion angles in these systems using Newman projections. The chapter then looks at the anomeric effect, which is a fundamental stereoelectronic effect.
Reaction Dynamics
Authors: Brouard M.
Published: September 2023

Reaction Dynamics provides a concise account of the dynamics and kinetics of elementary reactions in the gas phase, and is structured to emphasize the relationship between thermal rate coefficients and the microscopic mechanisms of chemical reactions. The theoretical framework necessary to predict the dynamics and kinetics of elementary reactions is introduced and illustrated by reference to numerous theoretical and experimental studies.
Matrices and representations in higher order point groups— degenerate representations
Authors: Ogden J.S
Published: September 2023

This chapter explores degenerate representations and higher order point groups. It talks about the ambiguity of both directions of an axis and the subsequent direction of rotation when higher order axes are involved, in which both directions are treated in a somewhat arbitrary way without prior qualification. It also illustrates how to derive representations in the majority of point groups with the use of vectors, atoms, bonds, or orbitals as bases. The chapter shows an example of the use of the reduction formula in a high symmetry point group, which derives the irreducible representations for the ls orbitals on the hydrogen atoms in methane. It reviews how the presence of high order axes leads to degenerate representations wherein the smallest matrices are either doubly degenerate or triply degenerate.
Appendix I
Authors: Ogden J.S
Published: September 2023

Answers to exercises

Chapter 1

(a) D3h, (b) C4v, (c) C3v, (d) C2h, (e) D6h, (f) C2v, (g) C2v? (h) D3h, (i) C3v, (j) D5h...
Introduction to Quantum Theory and Atomic Structure
Authors: Cox P. A.
Published: September 2023

Introduction to Quantum Theory and Atomic Structure envelops the basic concepts needed as background for this topic, and discusses atomic structure but not molecular applications. The first two chapters are concerned with the basic ideas and problems of wave-particle duality, the nature of wavefunction, and its statistical interpretation. Chapter 3 discusses some important applications of Schrödinger's equation to chemically relevant situations. Chapters 4 and 5 deal respectively with the hydrogen atom, and with the structure of many-electron atoms and the periodic table of elements. The emphasis throughout is on the physical concepts and their concrete application.
Answers to numerical problems
Authors: Cox P. A.
Published: September 2023

Chapter 1

6.86 m, 22.9 mm.

419 pm.

6.4 × 10−34 J s.

6.61 × 10−34 J s.

391 nm.

(a) 16 980 cm−1, (b) 2.104 eV, (c) 203.0 kJ mol−1.
Applied Organometallic Chemistry and Catalysis
Authors: Whyman Robin
Published: September 2023

Applied Organometallic Chemistry and Catalysis has two main objectives: to provide an overview of the influence of organometallic chemistry on homogeneous and heterogenous catalysis, and to provide an account of the principle commercial applications of homogeneous catalysis in industry. The first chapter provides some background to the subject, looking at the vital role that catalysis plays in the production of fuels and pharmaceuticals, amongst other things. The next chapter covers mechanistic organometallic chemistry. Chapter Three is related to hydroformylation and related reactions. The chapter that follows examines acetic acid and acetyl chemicals. The next two chapters look at nylon intermediates: buta- 1,3-diene hydrocyanation and olefin oligomerization and polymerization. The final chapter is about fine chemicals manufacture.
Acetic acid and acetyl chemicals
Authors: Whyman Robin
Published: September 2023

This chapter outlines the acetyl chemicals family which includes acetic acid, acetaldehyde, methyl acetate, acetic anhydride, and vinyl acetate. It traces the manufacture of acetic acid and its use in a wide range of end-products, such as vinyl acetate, acetate esters, as a solvent specifically for the oxidation of p-xylene to terephthalic acid, and in food and pharmaceutical applications. It also talks about processes used for the production of acetic acid and the acetyl chemicals which involve homogeneous catalysis by transition metal ions or complexes. The chapter describes the reaction of acetaldehyde with acetic anhydride. This affords ethylidene diacetate, which can be thermally de-acetylated to form vinyl acetate with the elimination of acetic acid. The chapter finally refers to alkane oxidation, which is a radical chain process and main propagation that does not need to involve the metal ion.
Nylon intermediates: buta-1,3- diene hydrocyanation
Authors: Whyman Robin
Published: September 2023

This chapter examines benzene, which has been used as the primary hydrocarbon source for the manufacture of Nylon via the intermediates adipic acid and hexamethylenediamine. It reviews the condensation polymerization of comonomers giving Nylon 6,6', which is the most common form of Nylon. It also outlines the multi-step sequence of reactions required for the manufacture of Nylon from benzene, which has provided a commercial incentive to introduce step changes by the development of simpler routes based on alternative feedstocks. The chapter recounts recent developments at BASF, the largest chemical producer in the world, which have demonstrated a viable alternative production route to adipic acid via the selective dicarbonylation of buta 1,3 diene. It mentions propylene that is converted into acrylonitrile by ammoxidation using well-known mixed oxide.
Olefin oligomerization and polymerization
Authors: Whyman Robin
Published: September 2023

This chapter describes the polymerization of olefins, which is the main industrial use of organometallic catalysts. It looks first at polyketones, which can be produced by the co-polymerization of olefins with carbon monoxide. Polyketones are of particular interest as specialty polymers in the context of their superior material performance properties. The chapter also outlines the metallocene complexes of the early transition metals and the complexes of the later transition metals, which are the two types of high-activity polymerization catalysts. The chapter explains how the olefin growth reactions involved in oligomerization and polymerization are governed by a sequence of initiation, propagation, and termination steps. It talks about the distribution of chain lengths for the growth reaction that can be derived mathematically from the Schulz-Flory distribution.