UC San Diego

The contents of this thesis are an investigation of how electrons behave within chemical systems. How electrons transfer between chemical species, and how we can perturb the electronic structure of molecules using external electric fields to polarize the electron density to alter their chemical behavior. The first section explores the structure of mixed-valent molecules, where an electron is shared between two ruthenium atoms with identical coordination environments within an oxo-centered triruthenium acetate cluster. The study uses a combination of synthesis, spectroscopy, and computational experiments to explore how the d-orbitals of those ruthenium clusters interact to delocalize the shared electron within a pi symmetric molecular orbital. The later studies focus on studying interfacial electric fields observed at electrochemical double layers. Chapter II of this thesis studies a “molecular ruler” which uses multiple spatially resolved vibrational probes in a monolayer of W(CO)5(1,4-phenylene diisocyanide) on an Au(111) surface. When observed under bias using vibrational sum-frequency generation spectroscopy the vibrational Stark shifts of the tungsten and gold bound isocyanide stretches reveal the distance dependence of the interfacial electric field. The last two chapters are focused on expanding the ability of the Kubiak lab to immobilize interesting molecules to electrode surfaces using more robust surface chemistry which can survive more extreme potential measurements. Chapter III details the synthesis and preparation of monolayers of a N-heterocyclic carbene monolayer with a fused pyridine functional group. These monolayers are explored as starting points for the bottom-up synthesis of functional monolayers. Chapter IV expands on this work and studies monolayers of oxo-centered triruthenium clusters immobilized using the PyNHC surface anchors developed in chapter III.