Organic Magnetic Materials

Abstract

The quest for purely organic magnetic materials has been the subject of intensive research activity during the last decade[1]. The goal of this research is the preparation of a material that combines the inherent properties of organic compounds with an usable magnetic property, like for instance ferromagnetism, ferrimagnetism or superparamagnetism. It is expected that such materials will have peculiar and probably unprecedented properties not shown by the traditional inorganic magnetic materials based on metallic or ionic lattices. Some of the foreseeable advantages of the organic and polymeric over the traditional materials have been discussed elsewhere.[2] They might become superior to traditional magnets as far as applications involving light absorption are concerned. In fact, organic compounds are usually transparent in many spectral regions and could be in principle obtained in optically active chiral forms. Thus, they might be used as magneto-optical switches and for the manipulation of polarized light in optical devices. Organic materials are generally electric insulators, so they might lead to insulating magnets in contrast with most of the traditional magnets that are electric conductors. Plasticity, flexibility and solubility in common organic solvents are general characteristics of organic/polymeric compounds that confer them an easy processability. Therefore, organic/polymeric magnets are ideal candidates to obtain magnetically active thin films and colloidal dispersions with ferrofluid properties. Biocompatibility is another characteristic of organic compounds that permits to imagine biomedical applications like for instance the use of organic magnets for drug addressing and as selective contrasting agents in nuclear magnetic resonance imaging. Finally, the state-of-the-art of organic chemistry techniques permits nowadays to synthesize tailor-made compounds and, therefore, to perform small structural modifications in order to tune their physical properties. Such a tunability is unprecedented in most of traditional inorganic materials and, therefore, open a wide range of practical opportunities.