High-spin Organic Molecules and Spin Alignment in Organic Molecular Assemblies

Abstract

Publisher Summary This chapter discusses organic molecules with more than two coupled spins ( S ≥ 3/2). They are arbitrarily called “high-spin molecules.” Molecular solids in which more than two unpaired electrons are aligned in parallel among neighboring molecules are also discussed. The chemistry of high-spin organic molecules and highly ordered spin alignment in organic molecular assemblies are expected to open up a new field in science and are considered also to be the best area in which interesting magnetic properties from organic materials can be looked for. Ferromagnetism is found in some minerals, inorganic compounds, metals, and alloys, but has never been associated with organic compounds. The chapter establishes the molecular designs that will permit the alignment of spins in organic molecules and organic molecular solids. On the basis of rigorous molecular design guided by theory and model experiments, a number of high-spin organic molecules have been synthesized and spin alignment in molecular assemblies has been advanced with reasonable success. The chapter introduces two approaches—that is, spin alignment within a molecule and among molecules is complementary to each other in expanding our understanding of chemical bonds and organic molecules and in developing novel organic magnetic materials.