Self-Assembly of Block Copolymers for the Fabrication of Functional Nanomaterials [thesis]

Li Yao
2014
Non-covalent interactions between metal ions and ligands such as water and methane have been extensively studied due to their biological and industrial importance. Gas phase studies can reveal the fundamental nature of these metal-ligand interactions. Photofragment spectroscopy is a powerful technique to investigate bond strengths, dissociation dynamics, molecular geometry and clustering and can be applied to electronic and vibrational spectroscopy. Using a home built apparatus, which combines
more » ... on production via laser ablation, separation via time-of-flight (TOF) mass spectrometry, laser excitation, and TOF fragment mass analysis, we have obtained electronic spectra of Co+(H2O) and vibrational spectra of M+(CH4)n (M=Co, Ni, Cu, Ag; n=1-4 or 1-6). The experimental techniques, apparatus, data acquisition and analysis employed throughout this thesis are described and explained in chapters 1 and 2. Chapter 3 discusses the electronic spectra of Co+(H2O), Co+(HOD) and Co+(D2O), measured from 13500 cm-1 to 18400 cm-1 using photodissociation spectroscopy. Transitions to four excited electronic states, with vibrational and partially resolved rotational structure are observed. The Co+-(H2O) binding energy is determined from the dissociation onset. The experiments and supporting calculations provide detailed information such as the electronic configuration of excited electronic states, how the Co+ electronic state affects the Co+-H2O bond strength, and how binding to Co+ changes the geometry of water. Chapter 4 discusses measurement and analysis of vibrational spectra of M+(CH4)m(Ar)3-m and M+(CH4)n (M=Co, Ni; m=1,2; n=3,4) in the C-H stretching region (2500-3100 cm-1). Interaction with the metal leads to large red shifts in the C-H stretche [...]
doi:10.7275/5474815.0 fatcat:il5575vaqjdpnfbn52t5uo2hoa