Temperature corrected kinetic method for the estimation of proton affinities, entropies of protonation and gas phase basicities.
Abstract
The kinetic method provides relative thermochemistry based on the competitive dissociation of mass-selected cluster ions. This dissertation proposes an extension to the current methods of analyzing kinetic method data. This method, termed the temperature corrected kinetic method (TCKM) is more rigorous than the current method and may potentially ease the limitations placed on the choice of reference compounds. In recognition of the temperature dependence of the gas phase basicity of the reference compounds, a temperature correction is made to these gas phase basicities using the effective temperature obtained from the kinetic method plots. This method simplifies and improves the conceptual basis of the double plotting method which is currently being used. Other work described in this dissertation includes the use of the kinetic method as a diagnostic in the structural characterization of cluster ions composed of the methyl cation and two alkanenitriles. Based on tandem mass spectrometry experiments and ab initio calculations, a structure in which one nitrile is N-methylated and the second nitrile is covalently bound to the cyano carbon was determined. Finally, simple instrumental modifications to a commercial triple quadrupole mass spectrometer were made in order to perform surface modifications to self-assembled monolayer (SAM) surfaces. Mass-selected ions were directed through the detector housing and allowed to impinge upon the surface. Numerous experiments were performed using the modified commercial instrument, including transhalogenation and soft landing.
Degree
Ph.D.
Advisors
Cooks, Purdue University.
Subject Area
Analytical chemistry
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