Inorganic Chemistry A Unified Approach

Second Edition

William W. Porterfield Hampden-Sydney College Hampden-Sydney, Virginia

СФ) Academic Press, Inc. A Division ofHarcourt Brace & Company San Diego New York Boston London Sydney Tokyo Toronto

Contents

Tables xi Preface xv

Part I Elements and Atoms

I Elements, Atoms, and Periodicity 3

1.1 The Origin of the Elements 4 1.2 The Abundance of the Elements 8 1.3 The Discovery of the Elements 12 1.4 Atomic Structure for One-Electron Atoms 15 1.5 Atomic Structure for Polyelectronic Atoms 21 1.6 Periodic Properties: Ionization Potential and Electron Affinity 1.7 Atomic Bonding: Differential Ionization Energies

and Electronegativity 42 1.8 Electrical Interactions between Atoms and Molecules 50

Problems 58

33

Part II Main-Group Compounds

2 Ions and Their Environments 63

2.1 Ions in Gases 63 2.2 Ions in Crystals 68 2.3 Ion Sizes in Crystals 80 2.4 Packing Symmetries for Spherical Ions 86 2.5 Ionic Oxides 97 2.6 Oxoanions—First-Row Elements 100 2.7 Oxoanions—Heavier Elements 105

v i CONTENTS

2.8 Ionic Halides 115 Problems 124

3 Directional Bond Networks and Solid State Chemistry 12 7

3.1 Ionicity, Polarity, and Directional Bonds 127 3.2 Polymeric Networks of Polar Bonds 130 3.3 Crystal Defects and Defect Structures 141 3.4 Superstructures and Polynuclear Systems 145 3.5 Layered Structures and Intercalation 150 3.6 Silicates 154 3.7 Nonsilicate Ceramics 165 3.8 Cluster Ions and Cluster Lattices 172

Problems 176

4 Bonding Theory for Covalent Molecules, Clusters, and Crystals 180

4.1 Molecular Orbital Methods 181 4.2 Molecular Orbitals and Polarity 199 4.3 Polarity and Hydrogen Bonding 200 4.4 Molecular Orbitals for Electron-Deficient Molecules 204 4.5 Molecular Orbitals for Electron-Rich Molecules 209 4.6 Covalent Radii 212 4.7 Covalent Bond Energies 216 4.8 Bonding in Elements 219 4.9 Bonding in Clusters 223 4.10 Band Theory and Metallic Bonding 228

Problems 235

5 Covalent Molecules and Crystals 238

5.1 Intermetallic Compounds, Alloys, and Glasses 238 5.2 Main-Group Organometallic Compounds 241 5.3 Boranes 248 5.4 Silanes and Molecular Hydrides 257 5.5 Organometalloids 264 5.6 Metalloid Clusters 269 5.7 Nonmetal Oxides 271 5.8 Nonmetal Halides and Oxohalides 279

CONTENTS vii

5.9 Interhalogens 287 5.10 Noble-Gas Compounds 291 5.11 Nonmetal Sulfides, Nitrides, and Polymers 295

Problems 304

6 Acids, Bases, and Solvents 307

6.1 Solvation and Electron Donation 308 6.2 Electron Acids and Bases 313 6.3 Proton Acids and Bases and Protic Solvents 320 6.4 Water and Aqueous Solution Systems 326 6.5 Acids and Bases in Water 333 6.6 Hydroxides, Hydrous Oxides, Oxocations, and Polyanions 336 6.7 Nonaqueous Protic Solvents 343 6.8 Aprotic Solvents 348 6.9 Superacids 353

Problems 356

Part /// Main-Group Reactions

7 Enthalpy-Driven Reactions I: Acid-Base Reactions 361

7.1 Spontaneity and Thermodynamics 361 7.2 Spontaneity, Mechanisms, and Rates 365 7.3 Protic Acid/Base Strength in Water 369 7.4 Protic Acid/Base Strength in Nonaqueous Solvents 377 7.5 Electronic Acid/Base Strength: Metal-Ion Lewis Acids 380 7.6 Electronic Acid/Base Strength: Metalloid Lewis Acids 385 7.7 Electronic Acid/Base Strength: Nonmetal Acids and

Charge-Transfer Complexes 390 7.8 Thermodynamics of Electronic Acid-Base

Interaction: EAEB + САСв 395 7.9 Optical Basicity 400

Problems 403

8 Enthalpy-Driven Reactions II: Redox Reactions 407

8.1 The Molecular Basis for Electron Transfer 408 8.2 Reduction Potentials and Free Energies 411 8.3 Redox Reactions in Aqueous Systems 420 8.4 Reduction Potentials in Nonaqueous Solvents 428

viii CONTENTS

8.5 Oxidizing Solvent Systems 431 8.6 Inert Organic-Solvent Systems 432 8.7 Inert Molten-Salt Solvent Systems 435 8.8 Reducing Solvent Systems: The Solvated Electron 438 8.9 Reduction Processes for Metal Ores 445 8.10 Redox Reactions in the Gas Phase and in the Atmosphere 448

Problems 454

9 Entropy-Driven Reactions 458

9.1 The Role of Entropy Changes in Free Energy 458 9.2 Low-Enthalpy Processes 461 9.3 High-Temperature Processes 468 9.4 Energy and Entropy in Noble-Gas Chemistry 476 9.5 Reactions Driven by Large ДЯ and AS: Explosives 478

Problems 482

Part IV Transition-Metal Compounds

10 The Properties of Transition Metals and Their Compounds 489

10.1 The Elements with d and /Valence Electrons 491 10.2 Bonding and Magnetism in d-Electron Transition Metals 499 10.3 Transition Metals as Metals 506 10.4 Ionic Surroundings: Transition-Metal Lattices and Minerals 513 10.5 Electrons in Lattices: Superconductors 523

Problems 526

/ / Ligand-Field Theory, Spectroscopy, and Magnetism 529

11.1 Ionic Surroundings: Crystal-Field Theory 530 11.2 Ionic Surroundings: Lattice Energies and Redox Stability 538 11.3 Covalent Surroundings: Transition-Metal MOs and

Ligand-Field Theory 542 11.4 Covalent Surroundings: Transition-Metal Pi Bonding 550 11.5 Electronic States and Terms for Transition-Metal Atoms 554 11.6 Electronic Spectra and Structures 566 11.7 Empirical Spectral Correlations and Distorted Symmetry 572 11.8 Transition-Metal Magnetochemistry 579

Problems 587

CONTENTS ix

12 Transition-Metal Donor-Acceptor Compounds 591

12.1 The Experimental Development of Donor-Acceptor Compounds 591

12.2 Coordination Numbers and Coordination Geometries 594 12.3 Coordination Numbers and the 18-Electron Rule 604 12.4 The Stability of Metal Complexes 609 12.5 Common Ligands and Complexes 616 12.6 Isomerism in Metal Complexes 627 12.7 Stereochemically Nonrigid Systems 634

Problems 639

13 Transition-Metal Covalent Compounds: Organometallic

and Cluster Molecules 643

13.1 Classes of Covalent Compounds 643 13.2 Organometallic Systems: Metal Carbonyls 645 13.3 Organometallic Systems: Metal Nitrosyls 655 13.4 Organometallic Systems: Pi-Electron Donors 659 13.5 Metal-Metal Bonding 677 13.6 Metal Clusters 684 13.7 Cluster-Bonding Theories 693

Problems 697

Part V Transition-Metal Reactions

14 Reaction Mechanisms for Donor-Acceptor

Compounds 703

14.1 Ligand-Substitution Reactions in General 704 14.2 Ligand Substitutions in Octahedral Complexes 707 14.3 Ligand Substitutions in Square-Planar Complexes 716 14.4 Redox-Reaction Mechanisms 721 14.5 Structure-Reactivity Correlations 726 14.6 Oxidative-Addition Reactions 732

Problems 739

15 Ligand Reactions and Catalytic Mechanisms

in Industry 744

15.1 Changes in Ligand Reactivity on Coordination 744 15.2 Metal Carbonyl Activation: The Water-Gas Shift Reaction 749

CONTENTS

15.3 Organometallic Catalysis: Polymerization 751 15.4 Organometallic Catalysis: Alkene Metathesis and

Isomerization 755 15.5 Organometallic Catalysis: Alkene Hydrocarbonylation

and Reduction 764 Problems 771

/ 6 Bioinorganic Molecules and Mechanisms 775

16.1 The Occurrence and Study of Metals in Biological Systems 775 16.2 Ligand Catalysis: Metalloenzymes as Acid/Base Catalysts 779 16.3 Ligand Catalysis: Metalloenzymes as Redox Catalysts 784 16.4 Redox Synthesis: Nitrogenase 797 16.5 Metalloproteins: Ligand Carriers, Metal Carriers,

and Metal Storage Proteins 803 16.6 Metal Ions as Structure Formers and Structure Probes 817 16.7 Metal Ions as Charge Carriers 828

Problems 833

/ 7 Photochemical Reactions of Transition Metals 836

17.1 Basic Photochemical Processes 837 17.2 Photosubstitution Reactions 844 17.3 Photoredox Reactions 848 17.4 Photoredox Reactions and Long-Range Electron Transfer

in Proteins 852 17.5 Ligand Photoreactions 857 17.6 Photoreactions and Metal Redox Control in Photosynthesis 862 17.7 Photoreactions and Solar Energy Conversion 870 17.8 Photochemistry and Photographic Systems 877

Problems 882

Appendix A Inorganic Nomenclature 885 Appendix В VSEPR Geometry Prediction and Hybridization 894 Appendix С Tanabe-Sugano Diagrams 900 Index 909