Influence of ortho- and meta-substituted N-heterocyclic dications towards the self-assembly of p-sulfonatocalix[4]arene

The interplay of different organic dications substituted at ortho- or meta-positions on the bis(methylene)phenyl ring and p-sulfonatocalix[4]arene, along with phosphonium cations and hydrated lanthanides affords new fascinating self-assembled structures.

Understanding the structural properties of p-xylylenebis(triphenylphosphonium) cation under different pH and anion conditions

Cis- and trans-conformers of the p-xylylenebis(triphenylphosphonium) dication can be accommodated in crystalline solids, depending on the pH of the solution and the presence of auxiliary anions (including p-sulfonatocalix[4]arene) and cations.

Gadolinium(iii)-mediated multi-component confinement of imidazolium cations in p-sulfonated calix[4]arene

Multi-component materials having supermolecules made up of mono- or bis-imidazolium cations shrouded by two p-sulfonated calix[4]arenes essentially form molecular capsules as part of the extended structure, with their formation mediated by Gd(iii), which is incorporated only in complex I.

Efficient packing of long flexible bis-imidazolium cations in the ubiquitous bilayers of their p-sulfonatocalixarene salts

The terminally charged head groups of the bis-imidazolium dications reside in one calixarene cavity while the other only reaches the sulfonate groups of the next bilayer, with the central spacer penetrating across the multi-layers and adjusted to fit in the tight bilayer.

Controlling the organization of phosphonium cations relative to p-sulfonatocalix[4]arene anions

A composite material containing supermolecules of 1,4-bis(triethylammoniomethyl)benzene and p-sulfonated calix[4]arene involves preferential binding of the ammonium moieties in the cavities of two geometrically opposed calixarenes with mono-phosphonium cations arranged in the endo-orientation with respect to the calixarene bilayers, as a multi-layered structure.

Illuminating host–guest cocrystallization between pyrogallol[4]arenes and the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate

Symmetry-generated packing of a cocrystal composed of c-butyl-pyrogallol[4]arene and the ionic liquid, 1-ethyl-3-methylimidazolium ethylsulfate.

Axially Aligned Confinement of 1,4-Bis(triethylammoniomethyl)benzene by Two p-Sulfonatocalix[4]arenes

A multiple component bi-layer complex containing 1,4-bis(triethylammoniomethyl)benzene and mono-phosphonium cations, and p-sulfonatocalix[4]arene involves preferential binding of the ammonium cation in the cavities of two geometrically opposed calixarenes with the mono-phosphonium cation embedded within a bilayer of calixarenes. The complex has channels between bilayers ~14 Å in diameter which are lined with both polar sulfonate groups and the hydrophobic surface of the central part of the ammonium cation. 1H NMR and 1D-ROESY experiments establish the formation of supermolecules of the bis-triethylammonium cation and two calixarenes in solution.

Site specific Co(III) sarcophagine binding in multi-component phosphonium and p-sulfonatocalix[4]arene systems

Co(III) sarcophagine-type cage molecules, [Co(diCLsar)](3+) or [Co(HONOsar)](3+), form either 1 : 1 or 1 : 2 host-guest inclusion complexes with mono-phosphonium cations and sodium p-sulfonatocalix[4]arene in the solid state yielding complex I [p-sulfonatocalix[4]arene·Co(diCLsar)·2{benzyltriphenylphosphonium}], complex II [2{p-sulfonatocalix[4]arene}·Co(diCLsar)·3{tetraphenylphosphonium}] and complex III [p-sulfonatocalix[4]arene·Co(HONOsar)·tetraphenylphosphonium]. The diversity of the structural types of these multi-component systems, including the orientation of the Co(III) molecules in the cavities of the calixarenes, depends on the nature of their terminal functional groups. The secondary coordination interactions binding between the Co(III) molecules and p-sulfonatocalix[4]arene have also been investigated in water using NMR techniques.