Stacking of Spiro-bis(1,9-disubstituted phenalenyl)boron Neutral Radicals

This approach to organic conductors is based on the neutral carbon-based free radicals of organic molecules. The idea can be rationalized if one considers the normal metals, such as copper and sodium. These inorganic metals conduct electricity because they possess a closed shell of electrons together with one electron in an outer ‘s’ orbital that becomes ionized in the solid state leading to the formation of inorganic free radicals in a sea of labile electrons.

In the present approach, we are pursuing phenalenyl-based neutral radical conductors. The unpaired electrons of the neutral radicals serve as charge carriers and this class of compounds has recently lead to the discovery of a neutral organic solid with the highest conductivity yet reported. The radical shown below is non-planar; that is, it is spiroconjugated at the boron atom so that spin density is delocalized over orthogonal p-systems into two dimensions. This novel system with the intrinsic unpaired spin has a potential to be utilized in spintronic and the electronic applications.

SEM Image of Purified CNT

Research in the nanotube group focuses on purification, quality control, chemistry and applications of carbon nanotubes (CNTs). Building on our established chemical functionalization routes, we are developing CNT materials for advanced composites, electronics, spintronics, energy production and biomedical applications. Primarily we work on thermal management in electronic packaging, chemical sensors and scaffolds for tissue engineering. These applications require very strict control of materials properties and consequently we are working to improve synthesis and purification techniques of CNTs.

Graphite consists of superimposed lamellae of 2D carbon–carbon covalent networks referred to as graphene. The separation of the graphene layers is a considerable challenge as a result of strong van der Waals forces. The focus on the extraordinary electronic properties of graphene has prompted a search for an efficient route to bulk materials.

Currently, our group is interested in various chemical processes to study the solution phase properties of single-layer graphene as well as electronic and thermal conductivities of thin film, bulk materials and polymer/carbon nanomaterial composites. Such chemically produced graphene sheets will find application as lubrication coatings, electrically conducting composites, thermal interface materials, and as transparent thin films.