Crystal structure vibrational characteristics and vibronic coupling of some conducting organic molecules

Abstract

The invention of organic conductors in the beginning of seventh decade of the 20th century has played an important role in science. Hereinbefore, it was believed that majority of organic solids are electrical insulators and the idea that such traditional organic materials could exhibit electrical, optical and magnetic properties which are characteristics of metals, seemed to be completely unacceptable. The picture has, however, changed in recent years, as researches on organic conductors have now given rise to new classes of molecular and polymeric materials with properties analogous to those of metals. In the last four decades there has been a revolution in terms of electrical conductivity, with a progression from insulating and semiconducting behaviour to conducting and superconducting behaviour. A new field known as organic conductors/molecular conductors has emerged at the interface of chemistry, physics and materials science. Conductive organic materials are lighter, more flexible, and less expensive than inorganic conductors. Also there are varieties to synthesize them and ease of processing. Unlike inorganic conductors, organic conducting materials are constructed from organic (carbon - based) small molecules. Superconductivity could be also achieved in these types of materials due to their highly crystalline nature. Organic superconductor may have more advantage over inorganic superconductor. For example, these have reduced weight and potential versatility having ability to modify their electrical attributes via chemical methods. Current applications of high temperature organic superconductors include; magnetic shielding devices, medical imaging systems, superconducting quantum interference devices (SQUIDS), IR sensors, analogue signal processing devices, and microwave devices.