Metal Ligation Regulates Conformational Equilibria and Binding Properties of Cavitands

Abstract

A self-folding cavitand binds quinuclidinium cation in its vase conformation and lanthanum ions in its kite conformation. Metal coordination provides a novel switching mechanism for the uptake and release of guests.

Structure and thermodynamics of a multimeric cavitand assembly

“…The ability of molecular hosts to impart specific orientation of guests within the interior cavity is of great interest for designing molecular capsules that can act as regio-selective reaction chambers. 25 In summary, the combination of X-ray crystallography and ITC for characterizing supramolecular reactions and products provides a more complete picture of the host-guest chemistry and demonstrates that the targeted pentameric supramolecular assembly, comprising a tetrapyridyl cavitand host and four 4-nitrobenzoic acid molecules, could be obtained in solution as well as in the solid state. This study illustrates the importance of utilizing complementary solution-and solid-state techniques in order to fully capture the structural chemistry as well as thermodynamic aspects of synthetic supramolecular chemistry.…”

“…Unit cell constants and orientation matrices were improved by least-squares refinement of 25 reflections thresholded from the entire dataset. Integrations were performed with SAINT, 21 using these improved unit cells as a starting point.…”

“…9 and recently as masking agents against undesired 25 photochemical reactions. 10 Although there are manysupramolecular interactions from which to choose when preparing capsules, the hydrogen bond remains the most widely used thanks to its tuneable strength, directionality and selectivity.…”

Bis(carbamoylmethylphosphine oxide) ligands fixed on the arene core via 1,2,3-triazole linkers: novel effective extractants for palladium, lanthanides and actinides

“…6 It is known that the efficiency and selectivity of CMPO type ligands usually increase with an increase in the amount of CMPO residues in a molecule. 7,8 Attachment of CMPO groups to molecular platforms such as calixarenes [9][10][11] and cavitands [12][13][14][15] led to further increase of extraction efficiencies and selectivities. Therefore, it seemed reasonable to attempt the synthesis of novel polyfunctional neutral organophosphorus compounds Ar-CMPO 1-7 and estimate their extraction properties towards Pd(II), U(VI), Th(IV) and lanthanides(III).…”

Synthesis And Characterization Of Nano Structured (4- Aminopyridine) Copper (Ii) Acetate Chloride

“…A caged compound must contain an interior cavity in which one or more molecules in ions can be trapped. Metal -assembled cages consists of multi-denate ligands held together by metal cations [2] which are unique because their bonds are more easily broken allowing the movement of guest molecules through the cavity [3]. These cages have potential applications in the area of molecular recognition, light harvesting, bio molecular transport and delivery systems, waste clean-up and time-released medicine [4].Fampyridine, a new sustained release oral tablet of 4-AP is currently under phase III clinic trial for its therapeutic efficacy in patients with multiple sclerosis (MS) and chronic spinal cord injury.…”