Molecular Paneling via Coordination:  Guest-Controlled Assembly of Open Cone and Tetrahedron Structures from Eight Metals and Four Ligands

Umemoto, Kazuhiko; Yamaguchi, Akemi; Fujita, Makoto

doi:10.1021/ja001411i

Cited by 134 publications

(74 citation statements)

References 17 publications

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“…[19] There have been fewer examples of tetrahedral metallosupramolecular assemblies where the ligand defines a face of the tetrahedron. These are a [M 8 L 4 ] distorted tetrahedron from Fujita and co-workers, [20] a distorted [M 12 L 4 ] tetrahedron reported by Robson and coworkers, [21] a handful of [M 4 L 4 ] tetrahedra with triscatecholate ligands, [22,23] an [M 4 L 4 ] tetrahedron formed from a diskshaped tridentate ligand, [24] and an [M 4 L 4 ] tetrahedron with a podand borate ligand. [25] Additionally, a flattened tetrahedral structure, in which the calixresorcinarene ligands act as the vertices of a metallosupramolecular tetrahedron, has been reported by Beer and co-workers.…”

Section: Methodsmentioning

confidence: 92%

Capsules and Star‐Burst Polyhedra: An [Ag₂L₂] Capsule and a Tetrahedral [Ag₄L₄] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands

Sumby

Hardie

2005

Angew Chem Int Ed

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Cyclotriveratrylene (CTV) is a macrocyclic host molecule that strongly favors a crown conformation, which gives it a bowl shape with a shallow molecular cavity.[1] Indeed, despite CTV being known for over 40 years, the alternative saddle conformation has only recently been isolated by the rapid quenching of a hot solution or melt, [2] or within a novel CTVbased cryptophane.[3] The bowl-shaped CTV is a cyclic trimer which has a distinctly spiked, pyramidal aspect. We wish to exploit this characteristic to create self-assembled capsules and polyhedra through the formation of metallosupramolecular assemblies. These would likewise have a spiked aspect that allows for significantly more internal space than could be afforded from a similar flat or flexible ligand. A range of spectacular polyhedral structures have been reported from the self-assembly of metal salts with multifunctional ligands. [4] CTV itself is not a good molecular component for such assemblies as it lacks predictable coordination sites for transition metals, hence we have synthesized a number of CTV analogues with pyridyl groups at the upper rim for use as ligands for these types of assemblies as well as coordination networks.[5] Notably, a number of crystalline hydrogenbonded assemblies feature tetrahedral clusters of CTV hosts arranged in a back-to-back fashion, [6] which excludes the possibility of forming an assembly with internal space. Likewise a 3D coordination polymer with a C 3 -substituted CTV derivative also shows this back-to-back stacking.[7] Self-assembled complexes of CTV-related host molecules that do show an internal space would result from the head-to-head association of host molecules. Examples are currently restricted to a dimeric [Pd 3 L 2 ] capsule that has been characterized in solution by Shinkai and co-workers.[8] This capsule results from the assembly of a trisubstituted CTV derivative possessing rigid pyridyl arms with cis-protected Pd salts. Covalently linked cryptophanes, where two CTV fragments are linked in a head-to-head fashion by organic spacers, are well established.[9]Other bowl-shaped host molecules have been shown to form both capsule assemblies and more complicated polyhedral structures. Capsule structures assembled from hydrogen bonds or coordination chemistry are known with calixarenes and calixresorcinarenes.[10] Considerably more complicated assemblies such as a cyclic trimer, [11] cyclic hexamers, [12] a tetrahedron, [11b] a snub cube, [13] icosahedron, [14] and a cuboctahedron [15] have also been reported from similar tetrameric molecular hosts.We report herein a new type of [M 2 L 2 ] dimeric capsule with a CTV-related host molecule in the complex [Ag 2 (tris(3-pyridylmethylamino)cyclotriguaiacylene) 2 (CH 3 CN) 2 ]·2 PF 6 · 4 CH 3 CN, along with the first example of a discrete polyhedral cluster larger than a dimeric capsule assembled with a CTVrelated host molecule. This latter complex [Ag 4 (tris(4-pyridylmethylamino)cyclotriguaiacylene) 4 (CH 3 CN) 4 ]·4 BF 4 · 7 CH 3 CN·2.8 H 2 O features a tetrahe...

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Section: Methodsmentioning

confidence: 92%

Capsules and Star‐Burst Polyhedra: An [Ag₂L₂] Capsule and a Tetrahedral [Ag₄L₄] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands

Sumby

Hardie

2005

Angew Chem Int Ed

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“…In this respect it resembles metal-ligand assemblies (for examples see refs. [24][25][26][27][28] in which the guest frequently determines which of several hosts are formed. For hydrogenbonded capsules the multiplicity behavior of Scheme 1 is unique (29)(30)(31)(32).…”

Section: Discussionmentioning

confidence: 99%

Reversible encapsulation by self-assembling resorcinarene subunits

Shivanyuk

Rebek

2001

Proc. Natl. Acad. Sci. U.S.A.

273

146

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Encapsulation complexes are assemblies in which a reversibly formed host more or less completely surrounds guest molecules. Host structures held together by hydrogen bonds have lifetimes in organic solvents of milliseconds to hours, long enough to directly observe the encapsulated guest by NMR spectroscopy. We describe here the action of alkyl ammonium compounds as guests that gather up to six molecules of the host module to form encapsulation complexes. The stoichiometry of the complexes-the largest hydrogen-bonded host capsules to date-is determined by the size and concentration of the guest. In 1997 Atwood and MacGillivray (1) reported the structure of resorcinarene 1a (Scheme 1) in the solid state and suggested its expanded possibilities for molecular recognition in solution (for a related structure see ref.2). Such compounds had hardly been ignored before then: As early as 1982, their curvature and functional groups provided the skeleton of the first cavitand (3) and subsequently, from two such units, the carcerands (4, 5) and hydrogen-bonded capsules (6-9) were prepared. The single resorcinarene unit has recognition capabilities in its own right. In 1988 Aoyama (10, 11) described the formation of stoichiometric, 1:1 complexes of 1b with dicarboxylic acids, ribose, and even with terpenes, and steroids in organic solution (12). Later, Aoki (13), Rissanen and coworkers (14), and others (ref. 15; a related structure including disordered solvent was obtained from 1d) found dimeric capsules of 1c with alkyl ammonium guests in the solid state. But when the structure of 1a revealed it to be a spectacular, spherical hexamer, surrounding an enormous cavity, it became apparent that encapsulation of much larger guests and alternate stoichiometries might be possible with this host. To our knowledge, no such complexes have been described in solution, and we introduce them here. Materials and MethodsThe resorcinarenes 1b and 1d were prepared by known procedures (16). The quaternary ammonium and phosphonium guests were purchased from Aldrich and Fluka and used without further purification. The stock solutions of 1b in commercial CDCl 3 were saturated by shaking with H 2 O before the complexation studies. All NMR spectra [one-dimensional 1 H-, 19 F-, 31 P-, two-dimensional rotating-frame Overhauser effect spectroscopy (ROESY)] were recorded with Bruker DRX 600-MHz spectrometer by using the solvent signal as internal reference. Results and DiscussionThe earlier finding that quaternary ammonium guests are useful for the detection of other capsular hosts in the gas phase by electrospray ionization-MS (17) was applied to the characterization of assemblies from Scheme 1. These salts act as ionic labels for MS but show high affinity for deep cavitands even in aqueous solution (18). The bonds that coat the inner surfaces of structures 1 provide a thin layer of negative charge that is complementary to quaternary ammonium salts. It seemed likely that the cation-interactions could be recruited to generate and stabilize assemblies of...

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“…While a number of reports exist on the behavior of cavity-containing supramolecular coordination complexes as hosts for atomic or molecular guests, [63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79] only a small number have additionally described bindingsignal transduction behavior such that the assemblies can function as chemical sensors. 30,[80][81][82][83][84][85][86][87] Even fewer have focused on such behavior in the solid state.…”

Section: Applications: Chemical Sensingmentioning

confidence: 99%

Supramolecular Coordination Chemistry and Functional Microporous Molecular Materials

Dinolfo¹,

2001

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An enormous number and variety of discrete, isolable, supramolecular-coordinationchemistry-based assemblies featuring well-defined nanoscale cavities have been designed, synthesized, and characterized over the past decade. A small number of these have subsequently been used as building blocks for microporous materials and now comprise an important component of an emerging chemistry of microporous molecular materials. The extant materials typically have displayed large void volumes, high internal surface areas, and the ability to withstand the systematic removal of solvent. These and other properties (chemical tailorability, alignment of cavities to form extended channels, good processability, etc.) suggest a number of potentially very exciting applications involving selective molecular transport, sensing, or chemical transformationswith many of these now supported by proofof-concept experiments.

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Molecular Paneling via Coordination: Guest-Controlled Assembly of Open Cone and Tetrahedron Structures from Eight Metals and Four Ligands

Cited by 134 publications

References 17 publications

Capsules and Star‐Burst Polyhedra: An [Ag₂L₂] Capsule and a Tetrahedral [Ag₄L₄] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands

Capsules and Star‐Burst Polyhedra: An [Ag₂L₂] Capsule and a Tetrahedral [Ag₄L₄] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands

Reversible encapsulation by self-assembling resorcinarene subunits

Supramolecular Coordination Chemistry and Functional Microporous Molecular Materials

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Molecular Paneling via Coordination: Guest-Controlled Assembly of Open Cone and Tetrahedron Structures from Eight Metals and Four Ligands

Cited by 134 publications

References 17 publications

Capsules and Star‐Burst Polyhedra: An [Ag2L2] Capsule and a Tetrahedral [Ag4L4] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands

Capsules and Star‐Burst Polyhedra: An [Ag2L2] Capsule and a Tetrahedral [Ag4L4] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands

Reversible encapsulation by self-assembling resorcinarene subunits

Supramolecular Coordination Chemistry and Functional Microporous Molecular Materials

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Product

Resources

About

Capsules and Star‐Burst Polyhedra: An [Ag₂L₂] Capsule and a Tetrahedral [Ag₄L₄] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands

Capsules and Star‐Burst Polyhedra: An [Ag₂L₂] Capsule and a Tetrahedral [Ag₄L₄] Metallosupramolecular Prism with Cyclotriveratrylene‐Type Ligands