Calixarene-based supramolecular photocatalysis
Abstract
This thesis presents the synthesis of BODIPY appended calix[4]arenes for use in
photocatalysis, building on the foundational ideas of Gutsche to utilise calixarene
molecular recognition capabilities for reaction enhancement. It was shown that
host-guest interactions within calixarene molecules increased the effective concentration
of starting materials and the efficiency of the 1O2 [4+2] cycloaddition with α-terpinene.
The first chapter provides necessary background of calixarenes and reactive dyes. The
second presents the synthesis of three BODIPY-appended calix[4]arenes theorised to be
strong photocatalysts based on previous work at Heriot-Watt University. Through
reaction monitoring using 1H NMR spectroscopy it was determined that the presence of
a cavity improved the conversion time of α-terpinene to ascaridole. Chapter three
examined what modifications to the initial photocatalysts had on the speed of α-terpinene
conversion. By introducing a phenolic spacer between the calix[4]arene and BODIPY
units, a deeper cavity was created. Under the same reaction conditions as chapter two,
reactions using these catalysts were seen to be distinctly slower.
Chapter four departs from the initial aim, examining in-situ 1H NMR spectroscopy to
track the conversion of 1O2 mediated reactions more accurately. This proved highly
successful producing data of good quality, although development of experimental
procedure is still required.