Organic materials are important to development of organic light emitting diodes (OLEDs) used in display technologies, organic photovoltaics (OPVs) used in the manufacturing of plastics that convert light to energy, and organic semiconductor technologies used for information processing and computing. The Frank Group designs and synthesizes conjugated organic molecules and polymers that contain open shell units comprised of either stable organic radicals or inorganic paramagnetic metal ions. The effect of open-shell electronic structure on the function and physical properties of the molecules is studied by solution state spectroscopy, physical measurements in the solid state, and computation. The goal of our research is the design and synthesis of organic materials for charge strorage, data storage and processing, and energy storage applications.

(I) Organic Magnetoelectronics (OMEMs): Spintronics or magnetoelectronics is an emergent technology in which both the quantum spin and charge of the electron is used to carry and store information in charge-based devices. In traditional charge-based electronics, equal populations of spin up () and spin down () charge carriers exist. In contrast, charge carriers can be induced to undergo a spin preference i.e. through spin-spin interactions) resulting in spin-polarized current. Electronic devices based on spintronics have the advantages of nonvolatile memory storage, decreased electrical power consumption, increased speed of data processing, and the exciting possibility to both store and process data on a single chip. We have designed and synthesized organic molecular materials that exhibit both conducting and magnetic properties of interest. We are currently developing structure-property relationships to evaluate how the electronic structure of these radical-based materials effects both magnetic and electrical properties in the solid state.

(II) Organic Electronics (OEs): Organic electronic materials are of interest for development of organic photovoltaic cells (OPVs), organic field effect transistors (OFETs), and electronic inks. Challenges exist in developing new organic materials with high mobilities and conductivities for electronics applications.We have developed synthetic methodology for a novel class of delocalized stable radicals that exhibit low ionization energies/electron affinities due to spin delocalization. These radicals can be functionalized for incorporation into a wide variety of polymeric and oligomeric structures and exhibit interesting electrical properties. We are currently synthesizing a large series of radicals and studying the effect of radical structure on the mobilities, electrical properties, and charge transport pathways of organic molecular materials comprised of spin delocalized redox active radicals. The long-range goal of this work is to make an organic electronic material with optimized mobilities for both OPVs and OFETs.

(III) Photomagnetism. Photoinduced molecular magnetic effects arise when magnetic systems are irradiated with light. Changes in magnetism can arise if the spin state of the photoexcited state is different from the ground state. Thermal relaxation to the ground state leads to reverse of the magnetization change, which often occurs at low temperatures. We have developed a novel strategy for controlling photomagnetic effects based on photochromic metal-organic complexes. The photochemical control of electronic structure observed in photochromic spirooxazines is coupled to ligand field sensitivity in paramagnetic transition metal complexes to give photomagnetic materials. Upon irradiation, photoisomerization between the closed spirooxazine form (SO) and the open photomerocyanine form (PMC state) occurs, leading to concomitant changes in delocalization, electronic structure, and ligand field at the paramagnetic metal center.