This book is based on the results of many years of experimental work by the author and his colleagues, dealing with the electronic properties of organic crystals. E. Silinsh has played a leading role in pOinting out the importance of the polarization energy by an excess carrier, in determining not only the character of the carrier mobility in organic crystals, but in determining the band gap and the nature of the all-important trapping site in these crystals. The one-electron model of electronic conductivity that has been so successful in dealing with inorganic semiconductors is singular ly unsuccessful in rationalizing the unusual physical properties of organic crystals. A many-body theory is required, and the experimental manifestation of this is the central role played by the crystal polarization enerqies in transferring the results obtained with the isolated molecule, to the solid. The careful studies of E. Silinsh in this field have shown tn detail how this polarization energy develops around the excess carrier (and also the hole-electron pair) sitting on a molecular site in the crystal. As with all insulators, trapping sites playa dominant role in reducing the magnitude of ~he current that can theoretically pass through the organic crystal. It is usually the case that these trapping sites are energetically distributed within the forbidden band of the crystal. For many years, an exponential distribution has shown itself to be useful and reasonably correct: However,' E.

The first edition of Pope and Swenberg's Electronic Processes of Organic Crystals, published in 1982, became the classic reference in the field. It provided a tutorial on the experimental and related theoretical properties of aromatic hydrocarbon crystals and included emerging work on polymers and superconductivity. This new edition contains the complete text of the first edition, plus an extensive new section, comprising nearly half of the book, which covers recent developments and applications with polymers. The book provides a unified description of what is known in almost every aspect of the field, from basic phenomena to the latest practical applications, which include LED's, photocopiers, photoconductors, batteries, transistors, liquid crystals, photorefractive devices, and sensors.

The Crystalline States of Organic Compounds is a broad survey of the techniques by which molecular crystals are investigated, modeled, and applied, starting with the fundamentals of intra- and intermolecular bonding supplemented by a concise tutorial on present-day diffraction methods, then proceeding to an examination of crystallographic databases with their statistics and of such fundamental and fast-growing topics as intermolecular potentials, polymorphism, co-crystallization, and crystal structure prediction by computer. A substantial part of the book is devoted to the techniques of choice in modern simulation, Monte Carlo and molecular dynamics, with their most recent developments and application to formed crystals and to the concomitant phases involved in nucleation and growth. Drawing on the decades-long experience of its author in teaching and research in the field of organic solid state, The Crystalline States of Organic Compounds is an indispensable source of key insights and future directions for students and researchers at any level, in academia and in industry. - Condenses theoretical information and practical methods in a single resource - Provides a guide on the use of crystallographic databases, structure statistics, and molecular simulations - Includes a large number of worked examples and tutorials, with extensive graphics and multimedia

Lattice defects of organic molecular crystals affect their optical or electrical properties by changing the local energy structure. Lattice defects also playa very important role in the chemical and physical properties, for example, as an active site of a catalyst or an initiating point of a solid state reaction. However, very little has been reported on the defect structure of real organic crystals. In the past ten years it became clear that the origin and the structure of the defects depend on the geometrical and chemical nature of the building units of the crystal, the molecules. Molecular size, form and anisotropy, charge distribution, etc. cause the characteristic structure of the defect. Accordingly, a defect structure found in one compound may not be found in others. The defect structure of an organic crystal cannot be defined solely by the displacement of the molecular center from the normal lattice site. A rotational displacement of a molecule is frequently accompanied by a parallel shift of the molecular center. In addition to the usual geometrical crystallographic defects, chemical defects are important too which originate, for example, from differences in the substitution sites of molecules carrying side groups. In order to reveal such defect structures, direct imaging of molecules by high resolution electron microscopy is the only direct method.

Organic Crystal Engineering provides reviews of topics in organic crystal engineering that will be of interest to all researchers in molecular solid-state chemistry. Specialist reviews written by internationally recognized researchers, drawn from both academia and industry, cover topics including crystal structure prediction features, polymorphism, reactions in the solid-state, designing new arrays and delineating prominent intermolecular forces for important organic molecules.

Spectroscopy of Defects in Organic Crystals presents a masterly summary of the widespread and voluminous literature on the subject, presenting theoretical and experimental investigations of electron and vibronic optical spectra of organic crystals. Electronic states of defects combine to form crystal near-to-band and band levels. These are discrete states in the vicinity of exciton bands, surface and dislocational excitons, etc. Some studies have expressed dissimilar or even conflicting opinions about the nature of observed phenomena. In the choice of the material, preference has been given to phenomena which have received a theoretical interpretation. Some attention is paid to observations which are not completely understood and also to effects predicted but not yet confirmed. The monograph will be useful for scientists as well as undergraduate and postgraduate students of solid state physics.

1.1 Preface Organic chemistry had its origin in chemicals which are synthesized by living cells. These chemicals consist of molecules whose skeletons are built up of carbon atoms. The remaining valences are connected with ligands such as hydrogen, halo gens, -OH,==O, -NH . Some of the skeletal carbon atoms can be replaced by non 2 metals such as oxygen, nitrogen, or sulfur {"heteroatoms"}. It is characteristic for the living world, not to be in a crystalline state. However it is possible to obtain single crystals from many organic compounds both of natural and synthetic origin. For a number of years the physics and chem istry of these crystals have stimulated fundamental research on a rapidly growing scale. The great variety of possible organic structures {as compared to inorganics} opens up a large field of new materials and of novel material properties; for previous literature reviews and data compilations see 1-40) and Chap. 6. The art of producing good and pure organic single crystals has developed hand in-hand with the ever growing requirements of basic research, arising from its interest in fundamental interactions in the solid state. Interactions manifest themselves in a very detailed way by energy transfer.

This book summarizes and records the recent notable advances in diverse topics in organic crystal chemistry, which has made substantial progress along with the rapid development of a variety of analysis and measurement techniques for solid organic materials. This review book is one of the volumes that are published periodically on this theme. The previous volume, published in 2015, systematically summarized the remarkable progress in assorted topics of organic crystal chemistry using organic solids and organic–inorganic hybrid materials during the previous 5 years, and it has been widely read. The present volume also shows the progress of organic solid chemistry in the last 5 years, with contributions mainly by invited members of the Division of Organic Crystal Chemistry of the Chemical Society of Japan (CSJ), together with prominent invited authors from countries other than Japan.