Self-Organized Porphyrin & Phthalocyanine Materials
“Anything that exists must be possible.” is often referred to as K. E. Boulding’s First Law.1 For example, nanoscale photonic devices exist that harvest light and convert it to electrochemical potential energy with near quantum efficiency, the photosynthetic apparatus; therefore it must be possible to construct nanoscale quantum-efficient photonic devices. At present, no man-made device comes even close to this efficiency. Self-assembled nanoscale motors such as helicases, isomerases, and kinesins exist, so nanoscale motors must be possible. Self-organized microscale bacteria with nanoscale components such as chloroplasts and mitochondria exist, so nanoscale powerhouses must be possible. Photodriven nanoscale ion pumps such as those in bacteriorhodopsin
exist, so nanoscale pumps must be possible. Combined, these illustrate the vast potential for molecular electronics, nanomachines, and nanodevices. We design and synthesize porphyrinoids that self-organize into photonic materials and evaluate the properties.
Porphyrinoids as molecular electronics: charge transport in hierarchically organized molecular assemblies in nano-confined matrices on Au(111)
The proposal that molecules can perform electronic functions in devices such as diodes, rectifiers, wires and capacitors, or serve as functional materials for electronic or magnetic memory, has stimulated intense research across physics, chemistry, and engineering for over 35 years. Because biology uses porphyrins
and metalloporphyrins as catalysts, small molecule transporters, electrical conduits, and energy transducers in photosynthesis, porphyrins are an obvious class of molecules to investigate for molecular electronic functions. Of the numerous kinds of molecules under investigation for molecular electronics applications, porphyrins and their related macrocycles are of particular interest because they are robust and their electronic properties can be tuned by chelation of a metal ion and substitution on the macrocycle. The other porphyrinoids have equally variable and adjustable photophysical properties, thus photonic applications are potentiated. At least in the near term, realistic architectures for molecular electronics will require self-organization or nanoprinting on surfaces.
Glycosylated Porphyrins, Phthalocyanines, and Other Porphyrinoids for Diagnostics and Therapeutics
The synthetic strategies to form carbohydrate conjugates to porphyrins, phthalocyanines, corroles, and other porphyrinoids include: (1) the synthesis of the dye precursors bearing the sugar; (2) appending the sugar the preformed macrocycle, has the distinct advantage of minimizing losses of sometimes precious
saccharides, and has been accomplished using substituion, click chemistry; (3) and other approaches such as adding glycodendrimers. These macrocycles are also extensively studied as photodynamic therapeutic (PDT) agents for the treatment of a variety of diseases such as cancer and infections
