A molecular Popeye: Li+@C60 and its complexes with [n]cycloparaphenylenes
Markus Freiberger1, Iris Solymosi1, Eva Marie Freiberger1
1Friedrich-Alexander-Universität Erlangen-Nürnberg, Institut fur Organische Chemie, Erlangen, Bayern, Germany. thomas.drewello@fau.de.
Abstract:
In this work, we compare for the first time the stability of [n]cycloparaphenylene ([n]CPP)-based host-guest complexes with Li+@C60 and C60 in the gas and the solution phase. Our gas-phase experiments reveal a significant increase in stability for the complexes featuring [9-12]CPP with Li+@C60. This increased interaction strength is also observed in solution. Isothermal titration calorimetry shows for the formation of [10]CPP⊃Li+@C60 a two orders of magnitude larger association constant than that for the C60 analog. Additionally, an increased binding entropy is observed. This study contributes to a better understanding of host-guest complexes between [n]CPPs and endohedral metallofullerenes at a molecular level, which is the prerequisite for future applications.
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