Exploring the ability to use endothermic chemical transformations as the basis of new heat transfer media
Investigating molecular control over charge mobility, electronic coupling, and band structure
Using the photothermal effect of nanoparticles to drive high-barrier thermal reactions under ambient conditions
The effect of alkanethiolate chain length on the gold core's electronic properties correlates with the core's average surface potential, which is modulated by ligand-to-metal charge donation. The degree of charge transfer depends on the difference between the dielectric constants of the solvent medium and of the ligand shell.
Para-substituted aromatic thiolate ligands control the electronic properties of gold nanoparticles, and the effects of these ligands can be explained with reference to parameters from traditional inorganic coordination chemistry.
Electronic coupling between ligands in mixed valence dithiolene molecules is reduced by asymmetric protonation of the ligands, resulting in charge pinning of the unpaired electron. The magnitude of the reduction in coupling, and the degree of charge localization, depend on the identity of the metal center.
Coupling a proton transfer to a ground state electron transfer within a nickel pyrazine dithiolene complex reduces the electronic coupling along the electron transfer coordinate by 5-fold. This loss in coupling is quantified using analysis of the intervalence charge transfer transition, which describes electron mobility in PCET systems.
Protonation of a gold-based pyrazine dithiolene complex results in only small changes to the electronic absorption spectrum of the complex, despite the larger effects known for nickel-based analogues, due to the fact that the frontier orbitals of the gold complex are more localized than those of the nickel counterparts.
Associate Professor of Chemistry
November 21, 2016
October 1, 2016
The Lear group welcomes graduate students Jonathan Fagan and Andy Widstrom.
September 23, 2016
Congratulations to Rob on his successful thesis defense: "The efficacy of Fe3O4 nanoparticles as robust and effective alternatives to gold nanoparticles as photothermal agents to drive high-barrier reactions."