Star Porphyrazines

Northwestern University, Evanston IL

Investigators

Abstract

Dr. Brian Hoffman, Department of Chemistry, Northwestern University, is supported by the Inorganic, Bioinorganic and Organometallic Chemistry Program of the Chemistry Division for work on star porphyrazines (pzs). Three general areas will be investigated. First, amino-functionalized pzs containing a core metal ion and metal-ions bound at the periphery will be used to define the systematics of heterometallic spin coupling and dithiolato-functionalized pzs will be used as the basis of pz assemblies and metal-linked pz ribbons that incorporate redox-switchable conduction and/or spin coupling. Secondly, pzs will be used to study fundamental questions about how molecular proximity/orientation to a metal surface influences interfacial charge injection, with possible applications as molecular electronic transport junctions, light emitting diodes and photovoltaic systems. Thirdly, the molecular optical transitions of porphyrazines adsorbed on Ag nanoparticles strongly couple to the particle localized surface plasmon resonances. This phenomenon will be explored and applied as chemical and biological optical nanosensors. The work supported by this award will have significant impact on a variety of scientific and technological applications. The class of compounds known as star porphyrazines will be highly useful as contrast agents in bio-imaging of tumors, and in such applications as dual opto/electrochemical metal-ion sensors. Pzs also hold promise of yielding dip-pen nanolithography "inks" that can be used to form patterns with controlled electrical properties on surfaces. Students and post-doctoral associates will gain fundamental and diverse skills not only in syntheses and physical characterization of these compounds, but also in exploring the potential application of the resulting products in nanotechnology, bio-imaging, and sensors.