טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentYaniv Moran
SubjectGas Phase Study of Aryl Cations and Aryl Alcohols -
Fragmentation, Electrophilicity and Complexation
with Alkali Metals
DepartmentDepartment of Chemistry
Supervisor Dr. Chagit Denekamp
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

Triphenylmethyl (trityl) cations and diphenylmethyl (benzhydryl) cations are generated from alcohols under acidic conditions. Due to their unique ability to form stabilized cations trityl and benzhydryl groups are very important in organic chemistry and quantitative measures of their properties are for example relative electrophilicity parameters as well as hydride affinity and kR+ values.

A useful tool for the study of ionic species like aryl cations is gas-phase ion chemistry using mass spectrometry. Although much of the interest in mass spectrometry is focused on its applications in analytical chemistry, mass spectrometers have proven to be powerful tools for studying the kinetics, mechanisms, and product distributions of gas phase, bimolecular organic reactions are determined using tandem mass spectrometry (MS/MS) isotopic labeling and molecular orbital calculations that provide valuable information. Data from these studies have furthered our fundamental understanding of the reaction chemistry of a wide range of species from simple inorganic ions to exotic, highly reactive organic ions. In fact, mass spectrometry has allowed chemists to uncover mechanistic details that could not be probed by other means. For example, ion chemistry in the condensed phase is often dominated by ion pairing and solvation interactions which can mask the intrinsic reactivity of the reaction partners. In the absence of solvation, gas phase studies can reveal the subtle details of reaction mechanisms and unambiguously characterize the intrinsic reactivity of ionic and neutral species. Moreover, comparison of gas phase and condensed phase data provides a powerful means for understanding the role that solvation and ion pairing play in determining the outcomes of ionic reactions.The presented research contains three deferent parts in which we have studied the fundamental properties of aryl groups and their gas phase chemistry using mass spectrometry techniques.