טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentBloch Victoria
SubjectDevelopment of Pyrazinium Based Metal Systems
DepartmentDepartment of Chemistry
Supervisor Professor Mark Gandelman
Full Thesis textFull thesis text - English Version


Abstract


The research of the rare cationic complexes present a great challenge and opportunity for implications in electrophilic catalysis. This research concentrated on development and studying a new class of cationic ligands and their complexes metal. The cationic ligand system, namely, pyrazinium system, is the focus of current work. The complexes based on the pyrazine and pyrazinium are unexplored and thus, present great opportunity to research cationic systems comprised from cationic ligand, pyrazinium, coordinated to cationic transition metal. In this research we were able to synthesize a completely novel and attractive highly electrophilic and reactive system. The pyrazinium ligand showed desired coordination in bidentate fashion to cationic metal centers as Pt(II) and Pd(II), the formed complexes are stable as solid and highly active in catalysis conditions thus, presenting a great challenge in electrophilic catalysis for CH bond activation.

The electrophilic system that was created was also explored as a reservoir for single electron which in turn could be used in catalysis. This presented additional novel pathway to explore pyrazinium based framework coordinated to cationic metal, in non-classical approach where the center of the catalytic reaction occurring at the metal center. The “non-innocent” ligand is the center of reactivity, while the metal serve as a support. The design of electron storage gave way to formation of an aminyl based radical, which is supported by the metal and the π conjugated system of the pyrazinium framework.

In summary, pyrazinium ligands have distinct properties which make them very attractive for electrophilic system framework and highly convenient as an electron storage system.