# Introduction to Inorganic Chemistry

Inorganic chemistry is the study of the synthesis, reactions, structures and properties of compounds of the elements. This subject is usually taught after students are introduced to organic chemistry, which concerns the synthesis and reactions of compounds of carbon (typically containing C-H bonds). Inorganic chemistry encompasses the compounds - both molecular and extended solids - of everything else in the periodic table, and overlaps with organic chemistry in the area of organometallic chemistry, in which metals are bonded to carbon-containing ligands and molecules. Inorganic chemistry is fundamental to many practical technologies including catalysis and materials (structural, electronic, magnetic,...), energy conversion and storage, and electronics. Inorganic compounds are also found in biological systems where they are essential to life processes.
This textbook (in its initial form) is intended for use in a first semester course in inorganic chemistry, covering the basic concepts in structure, bonding, and properties that underlie the field. The objective of this book is for students to understand how to use valence bond theory, crystal field theory, and molecular orbital theory to describe bonding in inorganic compounds, learn periodic trends in redox and acid-base equilibria, and learn the structures of solid elements and simple compounds. Building on this foundation we will develop a conceptual framework for understanding the stability and the electronic, magnetic, electrochemical, and mechanical properties of inorganic solids. We will also connect the chemistry of inorganic materials to some of their current and emerging applications, especially in the realm of nanoscale chemistry. By the end of the book the diligent student should know many of the elements in the periodic table as good friends, and the others at least as familiar acquaintances. This course will also help students understand the connection between inorganic chemistry and technological problems of current relevance, including:
* Where in the periodic table should we look for new semiconductors to make cheap and efficient solar cells?
* What's in a lithium battery, and how can we improve them for electric cars?
* How do inorganic compounds store and sequester hydrogen, methane, and CO$_2$?
* Some of the water supply in the developing world is contaminated with arsenic and other toxic substances. How can we clean up the water?
* How do nanoparticles provide better technology for flat screen displays, environmental cleanup, medical diagnostics and therapy?
* How do the devices (transistors, LEDs, piezoelectrics, alloys) in a cell phone and computer work?
We hope to add second-semester topics, including group theory, spectroscopy, organometallic chemistry, and bioinorganic chemistry, in future editions of this book.
Authors Born in 2014, this wikibook is a cooperative learning project of students in Chemistry 310 at Penn State University and Chemistry 2610 at the University of Pennsylvania. It is a work in progress, and students and teachers of inorganic chemistry are encouraged to edit the book and add to it.

### Chapter 1: Review of Chemical Bonding

* 1.1 Valence bond theory: Lewis dot structures, the octet rule, formal charge, resonance, and the isoelectronic principle
* 1.2 The shapes of molecules (VSEPR theory) and orbital hybridization
* 1.3 Bond polarity and bond strength
* 1.4 Discussion questions
* 1.5 Problems
* 1.6 References

### Chapter 2: Molecular Orbital Theory

* 2.1 Constructing molecular orbitals from atomic orbitals
* 2.2 Orbital symmetry
* 2.3 σ, π, and δ orbitals
* 2.4 Diatomic molecules
* 2.5 Orbital filling
* 2.6 Periodic trends in π bonding
* 2.7 Three-center bonding
* 2.8 Building up the MOs of more complex molecules: NH$_3$, P$_4$
* 2.9 Homology of σ and π orbitals in MO diagrams
* 2.10 Chains and rings of π-conjugated systems
* 2.11 Discussion questions
* 2.12 Problems
* 2.13 References

### Chapter 3: Acid-Base Chemistry

* 3.1 Brønsted and Lewis acids and bases
* 3.2 Hard and soft acids and bases
* 3.3 The electrostatic-covalent (ECW) model for acid-base reactions
* 3.4 Frustrated Lewis pairs
* 3.5 Discussion questions
* 3.6 Problems
* 3.7 References

### Chapter 4 : Redox Stability and Redox Reactions

* 4.1 Balancing redox reactions
* 4.2 Electrochemical potentials
* 4.3 Latimer and Frost diagrams
* 4.4 Redox reactions with coupled equilibria
* 4.5 Pourbaix diagrams
* 4.6 Discussion questions
* 4.7 Problems
* 4.8 References

### Chapter 5 : Coordination Chemistry and Crystal Field Theory

* 5.1 Counting electrons in transition metal complexes
* 5.2 Crystal field theory
* 5.3 Spectrochemical series
* 5.4 π-bonding between metals and ligands
* 5.5 Crystal field stabilization energy, pairing, and Hund's rule
* 5.6 Non-octahedral complexes
* 5.7 Jahn-Teller effect
* 5.8 Tetrahedral complexes
* 5.9 Stability of transition metal complexes
* 5.10 Chelate and macrocyclic effects
* 5.11 Ligand substitution reactions
* 5.12 Discussion questions
* 5.13 Problems
* 5.14 References

### Chapter 6 : Metals and Alloys: Structure, Bonding, Electronic and Magnetic Properties

* 6.1 Unit cells and crystal structures
* 6.2 Bravais lattices
* 6.3 Crystal structures of metals
* 6.4 Bonding in metals
* 6.5 Conduction in metals
* 6.6 Atomic orbitals and magnetism
* 6.7 Ferro-, ferri- and antiferromagnetism
* 6.8 Hard and soft magnets
* 6.9 Discussion questions
* 6.10 Problems
* 6.11 References

### Chapter 7 : Metals and Alloys: Mechanical Properties

* 7.1 Defects in metallic crystals
* 7.2 Work hardening, alloying, and annealing
* 7.3 Malleability of metals and alloys
* 7.4 Iron and steel
* 7.5 Amorphous alloys
* 7.6 Discussion questions
* 7.7 Problems
* 7.8 References

### Chapter 8 : Ionic and Covalent Solids - Structures

* 8.1 Close-packing and interstitial sites
* 8.2 Structures related to NaCl and NiAs
* 8.3 Tetrahedral structures
* 8.4 Layered structures and intercalation reactions
* 8.5 Bonding in TiS$_2$, MoS$_2$, and pyrite structures
* 8.6 Spinel, perovskite, and rutile structures
* 8.7 Discussion questions
* 8.8 Problems
* 8.9 References

### Chapter 9 : Ionic and Covalent Solids - Energetics

* 9.1 Ionic radii and radius ratios
* 9.2 Structure maps
* 9.3 Energetics of crystalline solids: the ionic model
* 9.4 Born-Haber cycles for NaCl and silver halides
* 9.5 Kapustinskii equation
* 9.6 Discovery of noble gas compounds
* 9.7 Stabilization of high and low oxidation states
* 9.8 Alkalides and electrides
* 9.9 Resonance energy of metals
* 9.10 The strange case of the alkali oxides
* 9.11 Lattice energies and solubility
* 9.12 Discussion questions
* 9.13 Problems
* 9.14 References

### Chapter 10 : Electronic Properties of Materials: Superconductors and Semiconductors

* 10.1 Metal-insulator transitions
* 10.2 Superconductors
* 10.3 Periodic trends: metals, semiconductors, and insulators
* 10.4 Semiconductors: band gaps, colors, conductivity and doping
* 10.5 Semiconductor p-n junctions
* 10.6 Diodes, LED's and solar cells
* 10.7 Amorphous semiconductors
* 10.8 Discussion questions
* 10.9 Problems
* 10.10 References

### Chapter 11: Basic Science of Nanomaterials

* 11.1 Physics and length scales: cavity laser, Coulomb blockade, nanoscale magnets
* 11.2 Semiconductor quantum dots
* 11.3 Synthesis of semiconductor nanocrystals
* 11.4 Surface energy
* 11.5 Nanoscale metal particles
* 11.6 Applications of nanomaterials
* 11.7 Discussion questions
* 11.8 Problems
* 11.9 References

### Chapter 12: Resources for Students and Teachers

* 12.1 VIPEr: Virtual Inorganic Pedagogical Electronic Resource: A community for teachers and students of inorganic chemistry
* 12.2 Beloit College / University of Wisconsin Video Lab Manual
* 12.3 Atomic and Molecular Orbitals (University of Liverpool)
* 12.4 Interactive 3D Crystal Structures (University of Liverpool)
* 12.5 Appendix 1: Periodic Tables
* 12.6 Appendix 2: Selected Thermodynamic Values
* 12.7 Appendix 3: Bond Enthalpies