Academic Year 2020/2021 - 1° Year

CHIM/03 - 6 CFU - 1° Semester

The course aims to deepen the knowledge on metallic and ionic solids and the properties of coordination compounds. The polyelectronic atom, electronic states, Crystal Field and MO theories, magnetic properties and optical spectra of inorganic complexes will be studied in depth. Furthermore, syntheses, electronic structures and properties of inorganic materials will be studied in depth. We will also provide basic knowledge on the main spectroscopic techniques. Finally, the basic concepts of inorganic photochemistry and homogeneous inorganic catalysis (knowledge and understanding) will be studied. The aim of the course is to acquire reasoning skills to rationalize the properties of solids and inorganic systems in solution (applying knowledge and understanding). At the end of the course students should have their own judgment: ability to propose appropriate inorganic systems for specific electrical, optical or magnetic properties (making judgments).

In particular:

The specific training objectives of this course are:

To understand the atomic structure in detail;

To understand the mechanisms of chemical bonding in solids and in coordination complexes in solution;

Understanding solid crystal structures and the main coordination polyhedra both in solid phase and in solution;

to know the relationships between electronic structures and the properties of insulators, semiconductors and metals and optical and magnetic properties;

Understanding the polyelectronic atom, the configurations, the electronic states and terms, the Russell-Saunders coupling, and the spin-orbit coupling;

to know the magnetic properties;

to know the characteristics of the transition element complexes;

to know the symmetry elements and operations;

to know the basics of group theory and its use in chemistry;

to know the CFT, LFT and MO theories;

Learning the treatment of optical spectra of inorganic complexes through the group theory;

to know the basic concepts of inorganic photochemistry;

to know the basics of the main spectroscopic techniques;

to discuss all proposed activities with scientific method and appropriate language.

Furthermore, in reference to the so-called Dublin Descriptors, this course helps to acquire the following transversal skills:

__Knowledge and understanding__:

• Capacity of inductive and deductive reasoning.

• Ability to rationalize property-structure correlations;

• Ability to set the prediction of a given optical spectrum of a given inorganic complex, using molecular symmetry and group theory and to interpret the related experimental spectrum.

__Ability to apply knowledge__:

• Ability to apply the acquired knowledge for the description of the properties of solids and complexes in solution, rigorously using the scientific method.

• Ability to interpret electrical, optical and magnetic phenomena;

• Ability to predict the chemical reactivity of transition metal systems

__Autonomy of judgment__:

• Ability to critical reasoning.

• Ability to identify the most appropriate solutions to confer particular properties to inorganic materials;

• Ability to identify the predictions of a theory or a model.

• Ability to evaluate the need for the use of complex models with respect to simple theories, in the description of the properties of inorganic materials.

• __Communication skills__:

• Ability to describe a scientific topic in oral form, with properties of language and terminological rigor, illustrating the reasons and results.

The course includes 6 credits (42 hours) of lectures. Students will actively be involved during the lessons in the classroom.

Should the circumstances require online or blended teaching, appropriate modifications to what is hereby stated may be introduced, in order to achieve the main objectives of the course.

1. SOLID STATE

Crystalline structures: anisotropy of crystalline systems, crystal structure and crystal lattice, primitive or elementary cell and unit cell, chemical and crystallographic repeating unit, connection and coordination numbers, coordination polyhedra; structures attributable to the octahedron and tetrahedron. Crystallographic parameters. Solids classification; metal solids, elements of symmetry, packing of spheres, compact structures: hexagonal (hcp) and compact cubic (ccp) structures. Gaps in compact structures. Non-compact structures: body-centered cubic structure and simple cubic structure. Bravais lattices. Ionic radii and binary and ternary ionic solids. Important ionic crystalline structures: sodium chloride, cesium chloride, fluorite, rutile, zinc blende and wurtzite, corundum. Graphite. Interstitial systems in compact structures: perovskites, spinels, ilmenite. Counting of atoms to define stoichiometry. Insulators, semiconductors and metals. Hints of band theory, lithium and beryllium bands, silicon and its doping. Notes on defects in solids, impurities and surfaces. Lattice energy: electrostatic theory, Madelung constant, Born-Haber cycle. Covalent solids; molecular solids.

2. POLYELECTRON ATOM

Particles and waves, the structure of the hydrogen atom and quantum numbers, electronic configurations of atoms and ions; Pauli principle, effective nuclear charge and energy levels in polyelectronic atoms, ionic rays. Polyelectronic atom, Configurations, states and electronic terms, quantum numbers for the polyelectronic atom, Russell-Saunders coupling, spin-orbit coupling, j-j coupling. Fundamental states for all electronic configurations of the elements of blocks s, p and d. Magnetic properties. General characteristics of the transition elements.

3. Group theory, group definition, infinite groups, finite groups, order of any group, multiplication tables, cyclic groups, subgroups, classes, conjugate elements and transformations by similarity, elements and operations of symmetry, products of symmetry operations , classes of symmetry operations, point symmetry groups, linear molecules, ferrocene, Platonic solids and their symmetry elements, classification of molecules by symmetry, types of symmetry groups, character tables, adapted symmetry functions, bases and representations of a group, reducible and irreducible representations, Mulliken's symbology for representations. Symmetry operations of the water and methane molecules and their representations, projection operators, SALC, symmetry orbitals and molecular orbital diagrams. Photoelectron spectrum of methane. Interactions of orbitals and formation of complexes. Coordination numbers four, five and six. Geometric isomerism in hexacoordinate and planar square complexes. Optical isomerism.

4. Magnetic properties of atoms and ions of transition elements, electronic configurations, oxidation states, angular moments and magnetic moments, [Ti (H2O) 6] 3+. Separation of the terms of the fundamental states in octahedral crystalline field. Magnetic susceptibility.

5. CFT-LFT-MO THEORIES

Classification of ligands: by donor atom; mono and polidentates; sigma and pi ligands. Theories of the crystalline and ligand fields. Splitting of a set of d orbitals in octahedral and tetrahedral crystal fields and their energy diagrams. Energy diagrams of distorted systems. High-low spin configurations. Jahn-Teller effect. Trend of the radii of 2+ ions of the first transition series in octahedral complexes. MO theory. Transformation properties of s, p and d orbitals in Oh and Td symmetry. Energy diagrams for octahedral, tedrahedral, square planar complexes using the MO theory. Rule of 18 electrons. Spectrochemical series of ligands.

6. OPTICAL SPECTRA OF INORGANIC COMPLEXES

Optical spectra of inorganic complexes and Lambert-Beer law. Dipolar electrical mechanism for optical transitions. Moment of transition. Orbital, spin, vibrational, rotational and translational wave functions. Gerade and ungerade functions. Rules for the evaluation of direct products in symmetry groups. Laporte's rule. Direct product in octahedral complexes. Consequences of the absence of the inversion element in tetrahedral geometry. d-d Transitions. Deviations from cubic symmetry. Jahn-Teller effect. Intensity and width of the absorption bands. Vibrations. Franck-Condon principle. Spin-orbit coupling. Tanabe Sugano diagrams and Racah parameters. Study of the spectra of [M (H2O) 6] n + ions for all "d" electronic configurations. Examination of the spectra of high and low spin [ML6] n + ions. Spectra of ion complexes of the II° and III° transition series. Spectra of distorted octahedral complexes and spectra of tetrahedral complexes. Spectrochemical and nephelauxetic series. Charge transfer spectra.

7. INORGANIC SYSTEMATICS FOR COMPOUND CLASSES

Chemistry of transition elements: general characteristics; preparation, properties and use of the elements. Most common compounds: synthesis and reactivity. Organometallic complexes for industrial use. Reagents of Grignard, Metal-alkyls, alkylidenes, carbenes, carbonyl compounds, cyclopentadienyls of the most important elements.

8. MAGNETIC PROPERTIES OF INORGANIC COMPLEXES.

Diamagnetism, paramagnetism and ferromagnetism. Magnetic measurements and correlations between magnetic properties and electronic structures of compounds.

9. CONCEPTS OF INORGANIC PHOTOCHEMISTRY.

10. NOTES ON THE MAIN SPECTROSCOPIC TECHNIQUES.

1) F. ALBERT COTTON, GEOFFREY WILKINSON, CARLOS A. MURILLO, MANFRED BOCHMANN, Advanced Inorganic Chemistry, 6th Edition, Wiley

2) N. N. GREENWOOD, A. EARNSMAW, Chimica degli Elementi, Piccin

3) W. W. PORTERFIELD, Chimica Inorganica, Zanichelli

4) D.F. SHRIVER, P.W. ATKINS, C.H. LANGFORD, Chimica Inorganica, Zanichelli

5) F. A. COTTON, La teoria dei gruppi in chimica, Tamburini