Studying Si-H Mode Sensitivity to Internal and External Perturbations through Vibrational Spectroscopy

Abstract

Over the course of this thesis, I hope to display an understanding of how a vibrational mode's sensitivity is dictated by inter- and intramolecular structure and composition. In the following chapters, a new vibrational ultrafast spectroscopic probe was used to study solvatochromism, confined solvent structure and dynamics, and structural dynamics of solid state materials, subsequently gaining knowledge of the probe’s inherent sensitivity and limitations in the process. First Chapter 2 provides a comprehensive background on 2D-IR spectroscopy, including the theory behind the technique and subsequent data analysis. Chapter 3 presents a solvatochromic study on a carbonyl vibration highlighting the analyses that will be used to extract molecular information from FTIR measurements of the same mode in different solvents. Chapter 4 utilizes some of the analyses from Chapter 3 to characterize a new Si-H probe intrinsically bound in a nanoporous silica sol-gel solid state sample. Chapter 4 also provides an introductory description of this novel mode’s sensitivity to solvent through solvatochromic analyses and ultrafast spectroscopy. Chapter 5 investigates a surface bound Si-H probe’s ability to measure interfacial solvent structure and dynamics inside mesoporous silica nanoparticles. Finally, Chapter 6 is a comprehensive study of the sensitivity of an Si-H mode to the structural and compositional evolution during a silica sol-gel formation and subsequent aging.