일 시 : 2013년 10월 23일, 3:30 PM
장 소 : 500동 L301호

-Abstract-
This lecture will discuss the use of templates for building large pi-conjugated macrocycles,
and will show that it is possible to go beyond simple 1:1 template:product stoichiometries to
direct the synthesis of very large nanorings using small templates. For example the Vernier
principle enables the figure-of-eight complex shown below to be prepared directly from a
porphyrin tetramer.
We have used the same strategy to synthesize a covalent nanoring consisting of 24 porphyrin
units with a molecular weight of 26 kDa and a diameter of 10 nm, well into the size-range of
proteins. The 24 porphyrin units are visible by STM, providing excellent confirmation of the
structure. The tertiary structure of the nanoring can be fixed by formation of a 26-component
sandwich complex with DABCO. Denaturation of this complex is highly cooperative, and
resembles denaturation of a protein. π-Conjugated nanorings of this type exhibit unusual
electronic and photophysical behavior, and mimic light-harvesting chlorophyll arrays.