Cyclophanes of different ring sizes featuring perylene-3,4:9,10-tetracarboxylic acid bisimide (PBI) linked by flexible malonates were designed, synthesized, and investigated with respect to their structural, chemical and photo-physical properties. It is...

We investigate the gas-phase chemistry of noncovalent complexes of [10]cycloparaphenylene ([10]CPP) with C 60 and C 70 by means of atmospheric pressure photoionization and electrospray ionization mass spectrometry. The literature-known [1 : 1] complexes, namely [10]CPP�C 60 and [10]CPP�C 70 , are observed as radical cations and anions. Their stability and charge distribution are studied using energyresolved collision-induced dissociation (ER-CID). These measurements reveal that complexes with a C 70 core exhibit a greater stability and, on the other hand, that the radical cations are more stable than the respective radical anions. Regarding the charge distribution, in anionic complexes charges are exclusively located on C 60 or C 70 , while the charges reside on [10]CPP in the case of cationic complexes.[2 : 1] complexes of the ([10]CPP 2 �C 60/70 ) + */À * type are observed for the first time as isolated solitary gas-phase species.Here, C 60 -based [2 : 1] complexes are less stable than the respective C 70 analogues. By virtue of the high stability of cationic [1 : 1] complexes, [2 : 1] complexes show a strongly reduced stability of the radical cations. DFT analyses of the minimum geometries as well as molecular dynamics calculations support the experimental data. Furthermore, our novel gas-phase [2 : 1] complexes are also found in 1,2-dichlorobenzene. Insights into the thermodynamic parameters of the binding process as well as the species distribution are derived from isothermal titration calorimetry (ITC) measurements.

Two [60]fullerene dumbbell-like molecules with a single or double perylene-3,4:9,10-tetracarboxylic acid bisimide (PBI) linker were synthesized to study the structural and photo-physical properties in addition to the complex formation with [10]CPP. Due to their special optical properties, it is possible to describe the complexation using conventional spectroscopic methods such as NMR and fluorescence. However, isothermal titration calorimetry (ITC) completed the analysis of the bis-pseudorotaxane formation by investigating the binding stoichiometries as well as the thermodynamic and kinetic parameters. It was observed that the PBI bridges do not inhibit the complexation with [10]CPP, giving rise to the formation of 1:1 and 1:2 complexes in o-DCB with affinities of around 105 M-1 alike to the [10]CPP⊃C60 reference system. A novel global analysis by combination of data sets from different techniques allowed us to follow the species distribution very precisely. ITC has proven to be a very powerful method for studying the complexation between fullerene derivatives and strained carbon nanohoops, which provides not only binding affinities and stoichiometries, but also all thermodynamic and kinetic parameters of the bis-pseudorotaxane formation. These results are of significant interest for the investigation of fullerene complexes in supramolecular chemistry and for their future applications in semiconductors and optoelectronics.

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...