טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentTom Mejuch
SubjectCorannulene-Based Synthetic Chemical Capsids
DepartmentDepartment of Chemistry
Supervisor Professor Emeritus Keinan Ehud
Full Thesis textFull thesis text - English Version


Abstract

A general synthetic strategy for chemical capsids at an intermediate size between C60 and spherical viruses has been recently developed in our group. The final structure could be achieved by self-assembly of symmetric pentagonal core units. By introducing different functional groups at the five edges of the pentagon, we wish to produce stable structures of icosahedral symmetry that can serve numerous functional roles. These structures are designed to assemble and disassemble under controlled conditions. For the core structure we have chosen corannulene, a polyaromatic hydrocarbon that consists of five adjacent benzene rings to form a non-planar, cup-shaped molecule. The design and synthesis of corannulene derivatives is determined by the specific bonding mechanism, such as hydrogen bonding, electrostatic interactions, metal ligation, etc.


The multi-step synthesis of corannulene, using improved literature procedures, has been accomplished. Introduction of five chlorine atoms on corannulene produced symmetric 1,3,5,7,9-pentachlorocorannulene that was used as a starting point for obtaining symmetrically functionalized corannulene derivatives. For achieving these goals direct nucleophilic substitution and transition metal catalyzed arylation and vinylation reactions were examined. Different catalytic systems and conditions were applied on model reactions. Modified Suzuki and Negishi cross-coupling reactions were found to give the most satisfying results. The obtained functionalized corannulene derivatives represent advanced building blocks that could be used as the desired pentagonal tiles for capsid formation.