Search results for "CUCURBITURILS"
showing 4 items of 4 documents
Strong Emission Enhancement in pH-Responsive 2:2 Cucurbit[8]uril Complexes
2019
Organic fluorophores, particularly stimuli-responsive molecules, are very interesting for biological and material sciences applications, but frequently limited by aggregation- and rotation-caused photoluminescence quenching. A series of easily accessible bipyridinium fluorophores, whose emission is quenched by a twisted intramolecular charge-transfer (TICT) mechanism, is reported. Encapsulation in a cucurbit[7]uril host gave a 1:1 complex exhibiting a moderate emission increase due to destabilization of the TICT state inside the apolar cucurbituril cavity. A much stronger fluorescence enhancement is observed in 2:2 complexes with the larger cucurbit[8]uril, which is caused by additional con…
Strong Emission Enhancement in pH‐Responsive 2:2 Cucurbit[8]uril Complexes
2019
Organic fluorophores, particularly stimuli-responsive molecules, are very interesting for biological and material sciences applications, but frequently limited by aggregation- and rotation-caused photoluminescence quenching. A series of easily accessible bipyridinium fluorophores, whose emission is quenched by a twisted intramolecular charge-transfer (TICT) mechanism, is reported. Encapsulation in a cucurbit[7]uril host gave a 1:1 complex exhibiting a moderate emission increase due to destabilization of the TICT state inside the apolar cucurbituril cavity. A much stronger fluorescence enhancement is observed in 2:2 complexes with the larger cucurbit[8]uril, which is caused by additional con…
Binding abilities of new cyclodextrin-cucurbituril supramolecular hosts
2015
Various combined techniques (UV–vis spectrophotometry, isothermal titration calorimetry, thermogravimetry, ESI-MS mass spectrometry, polarimetry and 1H NMR spectroscopy) were used in order to study the interaction between a new combined supramolecular host, namely a bow-tie-structured cyclodextrin–cucurbituril association solely held by non-covalent interactions, and a suitably selected guest, namely the N-(p-nitrophenyl)-1,8-diaminooctane hydrochloride. In particular, the use of different techniques highlighted the peculiar features of the possible host–guest supramolecular interactions under different concentration conditions.
Microwave-assisted synthesis of novel cyclodextrin–cucurbituril complexes
2011
Microwave irradiation was successfully used in order to obtain stable supramolecular aggregates between cyclodextrins and cucurbiturils, without the participation of any long-chain common ‘molecular thread’ guest. These aggregates were characterised by means of various different techniques, namely NMR, thermogravimetry, polarimetry and ESI-MS. Cross-analysis of experimental data allowed us to obtain insights on the stoichiometries of the composites and their thermal stabilities. The possible structures of the composites are briefly discussed, as well as the actual nature of their intrinsic stability.