0Experimental and Theoretical Investigation of Electronic Coupling in Metalloporphyrin Dimers and Trimers

Harvey Mudd College, Claremont CA

Investigators

Abstract

Professors Hal van Ryswyk and Robert Cave of Harvey Mudd College are supported by the Inorganic, Inorganic and Organometallic Chemistry program for their joint experimental and theoretical research on electronic coupling in a series of mixed-valence metalloporphryin dimers, which can be tailored to vary the degree of coupling. Inorganic materials synthesis will be carried out using solid-phase techniques followed by spectroscopic characterization, including Stark spectroscopy, of the charge-transfer bands of these compounds. The theoretical approach applies the Koopman's Theorem-Generalized Mulliken-Hush approach (KT-GMH) to calculate the coupling elements for these systems by semiempirical, Hartree-Fock, and Density Functional Theory-based methods. This collaborative experimental and theoretical effort will lead to a detailed understanding of the charge transfer characteristics of these systems, and provide stringent tests of the KT-GMH approach. The results will provide a firmer basis for new materials components, biomimetic models, and catalysts. The development of new theoretical chemistry tools thoroughly tested by experimental models is a critical step toward improving our understanding of large-scale charge-transfer systems. The metalloporphyrin oligomers studied under this award are attractive candidates for a wide range of materials science applications, with potential uses in molecular scale electronics, sensors, optical devices, and solar energy conversion schemes. Undergraduate students will receive multifaceted training in materials synthesis and characterization together with electronic structure calculations of metalloporphorin dimers and trimers.