Discrete 1 : 1 complexes and higher order assemblies formed from aminobenzene sulphonate anions and a tetraimidazolium "molecular box".

Use of isomeric aminobenzene sulphonate anions in conjunction with a tetraimidazolium "molecular box" leads to self-assembled embedded structures. Simple 1 : 1 complexes are formed at low concentrations in DMSO when the host : guest ratio is 1.0.

Post-synthetic modification of a macrocyclic receptor regioselective imidazolium ring-opening.

A facile post-synthetic modification of a tetracationic tetraimidazolium macrocycle, (, the "Texas-sized" molecular box (cyclo[2](2,6-di(1-imidazol-1-yl)pyridine)[2](1,4-dimethylenebenzene)), is described. Under mild basic conditions, ring-opening of the imidazolium moieties occurs. This results in two new isomeric dicationic macrocycles.

Multicomponent Self-Assembled Metal-Organic [3]Rotaxanes.

A set of environmentally responsive metal-organic [3]rotaxanes is described. These mechanically interlocked macromolecules may be prepared in quantitative yield via a one-pot procedure involving treatment of a flexible tetracationic macrocycle, known as the Texas-sized molecular box, with tri-1,3,5-benzenetricarboxylate anion and silver cations (Ag(+)). The use of this three-component mixture gives rise to a metal-organic [3]rotaxane via a self-assembly process that occurs under ambient conditions in DMSO-d6 solution.

Correction: Aromatic sulfonate anion-induced pseudorotaxanes: environmentally benign synthesis, selectivity, and structural characterization.

Correction for 'Aromatic sulfonate anion-induced pseudorotaxanes: environmentally benign synthesis, selectivity, and structural characterization' by Han-Yuan Gong et al., Chem. Commun.

Aromatic sulfonate anion-induced pseudorotaxanes: environmentally benign synthesis, selectivity, and structural characterization.

Anion-induced molecular threading is an emerging strategy for generating mechanically interlocked molecular architectures. Herein, we report the preparation of two pseudorotaxane structures generated from aromatic sulfonate anions and a tetraimidazolium-containing macrocycle in organic media, as well as under environmentally benign aqueous conditions.

Reversible anion-induced cross-linking of well-defined calix[4]pyrrole-containing copolymers.

Reversible addition/fragmentation chain-transfer polymerization is used to generate a calix[4]pyrrole methacrylate-derived copolymer. The material is found to undergo supramolecular cross-linking upon exposure to select dianionic species (e.g.

"Texas-sized" molecular boxes: building blocks for the construction of anion-induced supramolecular species via self-assembly.

It was previously established that the flexible tetraimidazolium macrocycle cyclo[2](2,6-bis(1H-imidazol-1-yl)pyridine)[2](1,4-dimethylenebenzene) (1(4+)) is capable of stabilizing higher-order supramolecular structures via both anion and cation recognition. Described herein is a set of structurally related imidazolium macrocycles (2(4+)-4(4+)) that contain modified central cores. The flexible nature of these new constructs is highlighted by the isolation of several independent crystalline forms for the same basic structure.

Rare-earth cation effects on three-dimensional metal-organic rotaxane framework (MORF) self assembly.

A set of metal-organic rotaxane frameworks (MORFs) are constructed with the use of a tetraimidazolium macrocycle, the terephthalate dianion, and the trivalent lanthanide metal cations Nd(III), Sm(III), Eu(III) or Tb(III) and are reported herein. The specific choice of the metal cation allows for control of the structure and luminescent properties of the resulting molecular frameworks.

The "Texas-sized" molecular box: a versatile building block for the construction of anion-directed mechanically interlocked structures.

Over the last two decades, researchers have focused on the synthesis and development of mechanically interlocked molecules (MIMs). The intramolecular motion of mechanical bonds and the ability to induce this effect with the choice of the proper external stimuli has prompted the development of macromolecular systems that possess the ability to "perform work" at the molecular level. Currently, researchers are working to incorporate interlocked species into complex structural systems, such as molecular frameworks and nanoparticles, and to create ever more elegant noncovalent architectures.

Neutral and anionic guests and their effect on the formation of pseudorotaxanes by using a flexible tetracationic imidazolium macrocycle.

The ability to control and direct molecular assembly has important implications in the design of environmentally responsive materials. Reported here is the use of competitive neutral- and anionic-guest recognition to control the formation, disruption, replacement-based construction and higher-order assembly properties of pseudorotaxane structures involving a large, cationic tetraimidazolium receptor. In particular, we showed that the chloride anion (as the tetrabutylammonium (TBA(+)) salt) serves to replace directly the 2,6-naphthalene dicarboxylate dianion from the preformed complex, involving this dianion.

Multi component self-assembly: supramolecular organic frameworks containing metal-rotaxane subunits (RSOFs).

A facile, one-pot synthesis of rotaxanated supramolecular organic frameworks (RSOFs) is reported. These systems consist of bis-carboxylate anions threaded through the core of tetraimidazolium macrocycles. Trivalent metal cations, yttrium(III) and smaller lanthanides, are used to "lock" the threaded strut in place.

Oligopyrrole macrocycles: receptors and chemosensors for potentially hazardous materials.

Oligopyrroles represent a diverse class of molecular receptors that have been utilized in a growing number of applications. Recently, these systems have attracted interest as receptors and chemosensors for hazardous materials, including harmful anionic species, high-valent actinide cations, and nitroaromatic explosives. These versatile molecular receptors have been used to develop rudimentary colorimetric and fluorimetric assays for hazardous materials.

Anion-directed assembly of a three-dimensional metal-organic rotaxane framework.

A three-dimensional extended, metal-organic rotaxane framework (MORF) that incorporates encircled "struts" has been synthesized through a one-pot self-assembly process involving a macrocyclic tetraimidazolium "molecular box", naphthalene dicaboxylate dianion, and Zn(II) cations. The present system represents progress towards controlling the features of three-dimensional metal-organic frameworks.

Environmentally responsive threading, dethreading, and fixation of anion-induced pseudorotaxanes.

The tetracationic macrocycle cyclo[2](2,6-di(1H-imidazol-1-yl)pyridine)[2](1,4-dimethylenebenzene) hexafluorophosphate (1(4+)·4PF(6)(-)) acts as a large, flexible "molecular box" that supports the formation of environmentally responsive anion-induced pseudorotaxanes, as well as other extended structures, including metal-linked supramolecular polyrotaxanes. Specifically, the combination of the tetracation 1(4+) and bis-carboxylate guests derived from 4,4'-biphenyldicarboxylic acid and 2,6-naphthalenedicarboxylic acid results in the formation of pseudorotaxanes that respond to changes in environmental stimuli, including pH and temperature. The resulting structures can be "locked into place" via the addition of a metal-linker in the form of Ag(I); this gives rise to an ordered metal-linked polyrotaxane.

Covalent Polymers Containing Discrete Heterocyclic Anion Receptors.

This chapter covers recent advances in the development of polymeric materials containing discrete heterocyclic anion receptors, and focuses on advances in anion binding and chemosensor chemistry. The development of polymers specific for anionic species is a relatively new and flourishing area of materials chemistry. The incorporation of heterocyclic receptors capable of complexing anions through non-covalent interactions (e.

A 'Texas-sized' molecular box that forms an anion-induced supramolecular necklace.

The 'blue box' (cyclobis(paraquat-p-phenylene) or CBPQT(4+)), developed by Stoddart and colleagues, forms effective charge transfer complexes with a variety of electron-rich species and has been used to support the formation of a wide range of interlocked structures. However, little effort seems to have been devoted to generalizing the blue box concept. We describe a new flexible tetracationic macrocycle-a 'Texas-sized' molecular box.

Substituent effects on the structure and supramolecular assembly of bis(dioxaborole)s.

Solid-state and solution analysis shows that dialkyl substituents on the central phenyl ring of bis(dioxaborole)s, such as , do not have an appreciable effect on the planarity but do significantly alter the supramolecular assembly of these compounds.

Self-repairing polymers: poly(dioxaborolane)s containing trigonal planar boron.

The molecular weight of poly(dioxaborolane)s can be controlled during the polymerization reaction or through post-polymerization processing in such a manner that hydrolytic damage to these materials may be repaired, thereby regenerating the polymer.