The synthesis and redox properties of new 1,3-dithiole systems

Abstract

The theory of conductivity in organic metals and a review of organic π-electron donors is introduced in Chapter One, outlining some of die many variations that have been made to the tetrathiafulvalene (TTF) molecule, the donor component in the first true organic metal. A range of new' alkylseleno-substituted ethanediylidene-2,2’-bis(l,3-dithiole) donors have been efficiently synthesised. These compounds form semi-conducting charge- transfer complexes with 7,7,8,8-tetracyano-p-quinodimethane (TCNQ). The synthesis, electrochemistry. X-ray crystal structure and magnetic properties are presented (Chapter Two). Various 1,3-dithiolium cations and 1,3-dithiole anions have been used in the synthesis of compounds targeted as high-spin systems (Chapter Three). The theory of organic ferromagnetism is discussed, and various compounds with interesting magnetic and redox properties have been prepared. Chapter Four deals with the synthesis of a series of conjugated, multi-1,3-dithiole, multi-chalcogen, π-electron donors. These compounds are members of the dendralene family of hydrocarbons and the crystal structure of a tricyclic [3]-dendralene is presented. The formation of semi-conducting charge-transfer salts is also discussed. Multistage redox behaviour of a new anthraquinodimethane derivative of TTF has been observed (Chapter Five), and cyclic voltammetic data and X-ray crystal structures of such systems are presented.