A tetraguanidinium macrocycle for the recognition and cavity expansion of calix[4]arene tetraoxoanions
作者:Julián Valero、Javier de Mendoza
DOI:10.1080/10610278.2013.835814
日期:2013.9.18
tetraguanidinium macrocycle which forms robust complexes with diverse calix[4]arene tetraoxoanions through hydrogen bonding and electrostatic interactions. The binding behaviour and affinity strength of these constructs have been measured by NMR and isothermal titration calorimetry. Besides, VT NMR experiments show that this novel cyclic tetracation is able to stabilise the cone conformation of these calix[4]arenes
Investigations into the assembly behaviour of a ‘rigidified’ <i>p</i>-carboxylatocalix[4]arene
作者:Robyn E. Fairbairn、Simon J. Teat、Irene Ling、Scott J. Dalgarno
DOI:10.1039/c9ce01326a
日期:——
supramolecular building blocks capable of forming a range of bi-layers, capsules and nanoscale tubules in the solid state. Here we report the synthesis of a new ‘rigidified’ analogue, as well as investigations into its self-assembly and related coordination chemistry. These behaviours are reminiscent of other p-carboxylatocalix[4]arenes despite the presence of rigidifying groups at the lower-rim, suggesting
A remarkable influence of the rigidity of the calix[4]arene platform in determining the recognition properties of mobile2 and rigid cone6 watersoluble peptidocalix[4]arene receptors towards α-amino acids and aromatic quaternary ammonium cations has been found.
A calix[4]arene–porphyrin duplex was prepared by mixing equimolar amounts of hydroxy or carboxy calix[4]arene derivatives and pyridyl or o-aminophenylporphyrin derivatives. Electrospray ionization mass spectrometry (ESI-MS) was applied to screen a suitable pair of a calix[4]arene and a porphyrin. meso-Tetra(2-pyridyl)porphyrin formed a duplex with tetrahydroxy or tetrahydroxymethylcalix[4]arene via triple or quadruple hydrogen bonds. 1H NMR spectra showed that the tetrahydroxycalix[4]arene was symmetrically located upon the porphyrin ring, whereas trihydroxycalix[4]arene was slanted on the porphyrin ring. The duplex of meso-tetra(2-pyridyl)porphyrinatocobalt(II) and tetrahydroxymethylcalix[4]arene formed a complex with benzylimidazole, which was capable of reversible dioxygen-binding. The capping structure upon porphyrin provided by calix[4]arene raised the life-time of dioxygen-adduct compared with the porphyrin without calix[4]arene.