Mass spectrometry characterization of novel synthetic materials.

摘要

This dissertation focuses on the characterization of novel synthetic materials by mass spectrometry approaches. Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and electrospray ionization mass spectrometry (ESI-MS) are utilized to perform single-stage mass spectrometry experiments, providing mass (m/z) information. ESI-MS coupling with ion mobility spectrometry has been achieved to determine molecular structures and conformations. The compounds examined in this dissertation are polyhedral oligomeric silsesquioxanes (POSS) diadducts, self-assembled supramolecules (two-dimensional and three-dimensional), including metallo-triangles, a terpyridine-based tetramer, bisterpyridyl o-carborane-based metallosupramacrocycles, and a tristerpyridine-based nanosphere.;Chapter IV describes the isomeric architectures of POSS adducts, including those diadducts synthesized via thiol-ene chemistry and azobenzene functionalized POSS adducts. The compositions of POSS diadducts were quantified, identifying the para isomer, as the major product, in which steric hindrance is minimized.;Chapter V discusses the effect of counterions on the collision cross-sections (CCSs) of self-assembled metallo-triangles. Molecular structures of triangles in different charge states were simulated and the CCSs were calculated theoretically for comparison with experimentally derived values.;Chapter VI concerns supramolecular architectures. Conformers of supramolecules and their fragments were analyzed by ion mobility mass spectrometry. The corresponding fragmentation mechanisms were also elucidated. Ion mobility mass spectrometry combined with gradient tandem mass spectrometry (gMS2) is shown to be ideally suitable for probing the structures and intrinsic stabilities of metallo-supramolecules.