Electrons in Molecules

Abstract

This book treats in a unified way electronic properties of molecules (magnetic, electrical, photophysical), culminating with the mastering of electrons: molecular electronics. Chapter 1 reviews basic concepts. Chapter 2 describes the magnetic properties due to localized electrons. This includes phenomena such as spin crossover, exchange interaction from dihydrogen to extended molecular magnetic systems, and magnetic anisotropy with single-molecule magnets. Chapter 3 is devoted to electrical properties due to moving electrons, first considering electron transfer in discrete molecular systems — in particular, in mixed valence compounds — and then, extended molecular solids described by band theory. Special attention is paid to structural distortions (Peierls instability) and interelectronic repulsions in narrow-band systems. Chapter 4 examines the properties of excited electrons responsible for photophysical properties, and dicusses electron transfer in the excited state and its application to photodiodes, organic light-emitting diodes, photovoltaic devices, and water photolysis. Energy transfer is treated in a similar way. Photomagnetism (how a photonic excitation modifies magnetic properties) is also introduced. In Chapter 5, most of the previous knowledge is combined in molecular electronics. The concept of hybrid molecular electronics (molecules connected to metal electrodes) is developed, fed by examples such as molecular wires, diodes, memory elements, field-effect transistors, and the use of magnetic properties for molecular spintronics. The extension to quantum computing is discussed.