Date of Graduation

Summer 2014

Degree

Master of Science in Chemistry

Department

Chemistry

Committee Chair

Eric Bosch

Keywords

crystal engineering, supramolecular chemistry, fluorine, sonogashira, NMR, halogen bonding, self-complementary dimers, x-ray, polyfluorinated benzene

Subject Categories

Chemistry

Abstract

The goal of crystal engineering is to design solids with useful properties. Towards this goal, molecules are designed to self-assemble from solution into the solid state through synergistic intermolecular interactions to form crystalline supramolecular structures. Over the past decade, halogen bonding has been recognized as a useful interaction for self-assembly. The research described herein is focused on the synthesis of planar polyaromatic molecules designed to form self-complementary dimers in solution and in the solid state. The Sonogashira coupling reaction was used to couple ethynylpyridines with polyfluorinated iodo and bromobenzenes. Five molecules were synthesized of which four formed the first reported self- complementary halogen bonded dimers. 1H, 19F and 13C NMR analyses were used for the conformation of target molecules. Single crystal X-ray structures of a series of molecular-dimer forming molecules are presented. The self-complimentary dimers exhibited short nitrogen-iodine or nitrogen-bromine distances between 81 and 89% of the sum of the van der Waals radii. Short H...F and π-π stacking interactions were also identified within the three dimensional structures.

Copyright

© Shalisa M. Oburn

Campus Only

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