Inorganic Chemistry 2

Overview

NAME CONTRIBUTION
Prof. J. Holbrey
j.holbrey@qub.ac.uk Main Group Chemistry (10 Lectures, 2 Seminars, lab co-ordination)
Prof. S.L. James
s.james@qub.ac.uk Coordination Chemistry (II) (10 Lectures and 2 Seminars);
Dr. M. Muldoon
m.muldoon@qub.ac.uk Inorganic Reaction Mechanisms (10 lectures, 2 seminars).

COORDINATION CHEMISTRY:
 The aim of this course is to extend your knowledge and understanding of transition metal chemistry. We will consolidate and extend on the material from your Coordination Chemistry lectures in year 1, beginning with fundamental properties of, and trends in, the d-block, brief revision of basic aspects of coordination complexes, including oxidation states, geometries, isomerism, etc., and how to write their chemical formulae and name them. We then revise and extend Crystal Field Theory, cover Ligand Field Theory and HSAB theory, all of which help to explain the observed characteristics of these complexes (e.g. colours, magnetism, geometries, stabilities etc). As the course progresses you should make sure that you are clear on which theories explain which observations, what the limitations of each theory are, and be able to apply them to solving problems. We finish with the basics of organometallic compounds of the transition metals.
 Introduction: General properties of, and trends within, the transition elements: sizes, electronegativities, oxidation states, etc. Revision of important basics of coordination chemistry from year 1: ligands (Lewis bases), Lewis acids. How to write formulae and name coordination complexes. Deducing oxidation states and d-electron configurations.
 The coordination sphere: Revision and extension of coordination numbers, geometries, denticity, chelating ligands. The chelate and macrocyclic effects. Types of isomerism: geometrical, optical, ambidentate ligands.
 Hard and soft acids and bases (HSAB theory): Which combinations of ligands and metals form strong bonds and which form weak bonds?
 Crystal Field Theory: Brief revision of the concepts from year 1: shapes of the d-orbitals, deducing crystal field splitting diagrams for octahedral and tetrahedral complexes. Square-planar and trigonal bipyramidal geometries. Crystal field stabilisation energies. Hydration enthalpies of M2+ ions. Factors influencing ∆. The spectrochemical series. High-spin and low-spin complexes. Jahn-Teller effects.
 Seminar: consolidation of topics 1-4 and problem solving.
 Colour d-d transitions, metal-to-ligand charge transfer, UV-visible spectra.
 Magnetism magnetic moments, the spin-only formula.
 Ligand Field Theory pure σ-donor ligands, π-donors, π-acceptors. Molecular orbital diagrams for octahedral complexes, effects of π-bonding. Full explanation of the spectrochemical series.
 Metal-metal bonding: description of bonding in dimetal compounds
 Introduction to transition metal organometallic compounds: Complexes containing simple organic ligands such as hydride, alkyl groups, and CO.
 Seminar: consolidation of topics 6-10 and problem solving.

INORGANIC REACTION MECHANISMS:
 This course describes some pathways by which molecular inorganic compounds react in solution. Firstly we will discuss why inorganic molecules react and what determines their stability and reactivity and then outline some common reaction mechanisms and factors that influence the path of reactivity.
 Introduction: The study of reaction mechanisms is useful in industrial, bioinorganic and synthetic chemistry; methods of study include use of in situ spectroscopy, Beer-Lambert Law.
 What Determines Reactivity? Reaction profile, transition state, activation barrier, stability.
 Stability: Formation constant, sterics and electronics, theories of bonding, MO theory, crystal field theory, Irving - Williams series, CFSE, chelate and macrocyclic effect.
 Reaction Kinetics and Rate: Reaction profiles and rate, EACT, labile / inert complexes, theory of microscopic reversibility, elementary reactions, Arrhenius equation, revision of rate laws, first, second and pseudo-first order.
 Reaction Types: Introduction to addition, dissociation, substitution; changes in geometry and stereochemistry, allogons, Berry pseudorotation, insertion / elimination, oxidation / reduction, oxidative addition / reductive elimination.
 Insertion and Elimination: Insertion, 1,1-migratory insertion, 1,2-migratory insertion; insertion of CO: isotope labelling, factors effecting rate, Lewis Acid promotion; insertion of alkenes: stereochemistry, coplanar transition state, polymerisation; elimination: β elimination, α,γ,δ-elimination, cyclometallation.
 Oxidation/Reduction: Inner sphere mechanism: bridging ligands; outer sphere mechanism: reorganisation and rearrangement energy, Marcus theory, slow electron transfer.
 Oxidative Addition/Reductive Elimination: Oxidative addition: concerted addition, sigma complex, SN2, radical and ionic mechanisms; Reductive elimination; homogeneous catalysis
 Substitution: Langford-Gray nomenclature, mechanisms A, Ia, Id, D, entering group; leaving group, nucleophilicity, spectator ligand, 2 and 3 coordinate complexes; tetrahedral complexes, nitrosyl complexes, square planar complexes: solvent substitution, stereochemistry, trans effect and influence; five coordinate complexes; octahedral complexes: Co(III) complexes, solvolysis, CFAE, entering, leaving and spectator group effects, base catalysed substitution, shift mechanism.

MAIN GROUP CHEMISTRY:
 This course discusses general trends in main group chemistry, and then highlights these through a discussion of the significant chemistry of each of the groups in the p-block, and organometallic chemistry of the s- and p-blocks. At the end of the course, the student will be familiar with each of the elements, and be able to predict the reactivity of and synthetic procedures to common main group compounds.
 Introductory Remarks: Brief revision of basic concepts including Lewis structures, valence electron calculations, oxidation states and prediction of molecular shapes, understanding of general trends in the periodic table (effective nuclear charge, radii, ionisation energy, electronegativity).
 Exploration of general trends in the p-block: Transition metal and lanthanide contraction, inert pair effect, second row anomaly, diagonal relationships and colour, oxidation states, trends in Lewis acidity.
 Organometallic Chemistry of the s- and p-block elements: Synthesis, bonding, reactivity and physical properties of typical lithium, sodium and potassium hydrocarbyls, Grignard reagents, organometallic chemistry of groups 12 to 14 (zinc, cadmium, mercury, aluminium, thallium, tin and lead) including synthesis structure and reactivity.
 Descriptive Chemistry of Group 13: Occurrence and recovery, descriptive chemistry of the elements, halides, hydrides and boranes, oxides and the boron nitrides.
 Descriptive Chemistry of Group 14: Descriptive chemistry of the elements, halides, hydrides, oxides and sulfides. Applications of silicones.
 Descriptive Chemistry of Group 15: Descriptive chemistry of the elements, hydrides, oxides, oxyacids and phosphazenes.
 Descriptive Chemistry of Group 16: Descriptive chemistry of the elements, hydrides, oxides, oxyacids, halides and sulfur-nitrogen compounds.
 Descriptive Chemistry of Group 17: Descriptive chemistry of the elements, hydrides, oxides, oxyacids, interhalogens, polyiodides and charge transfer complexes.
 Descriptive Chemistry of Group 18: Descriptive chemistry of the elements, fluorides and oxides.
 Seminar: Consolidation of topics and worked example problem solving.

Learning Objectives

The student should gain a deeper understanding of the various theories (e.g. Crystal Field, Ligand Field, HSAB etc) which help to explain the bonding and behaviour of transition metal compounds. The student should be able to apply these theories to problem solving (e.g. predicting geometries, magnetic properties, relative stabilities, isomerism, outcomes of reactions etc). The student should learn about the relationship between structure and reactivity and the main mechanisms by which dissolved inorganic molecules react. This will enable he/she to suggest likely reaction mechanisms for some simple inorganic reactions. The student will learn to evaluate and contrast the reactivity of similar complexes and predict likely products of reaction. The student will gain a broad overview of the fundamental properties of main group compounds and their reactivity patterns. The student should be able to understand and rationalise the properties and reaction chemistry of various main group compounds on the basis of a few straightforward principles.

Skills

Skills are mainly subject-specific involving increased understanding and knowledge of the elements and their compounds. The students also have the opportunity to develop verbal presentation and reasoning skills through tutorials, and observational and scientific reporting skills through practical work.

Assessment

Assessment:
Examination 70 %
Practical 25 %
Tutorial 5 %

Course Requirements:
Practical attendance at 80 %,
Practical report submission 80 %,
Both Coursework and Examination must be passed at 40 %