A Molecular Solomon Link

Pentecost, Cari D.; Chichak, Kelly S.; Peters, Andrea J.; Cave, Gareth W. V.; Cantrill, Stuart; Stoddart, J. Fraser

doi:10.1002/anie.200603521

Cited by 251 publications

(122 citation statements)

References 64 publications

Supporting

Mentioning

117

Contrasting

Unclassified

Order By: Relevance

“…M echanically interlocked and knotted compounds, such as rotaxanes (1)(2)(3)(4)(5), catenanes (6-10), suitanes (11,12), trefoil knots (13)(14)(15)(16)(17), Borromean rings (18)(19)(20), and Solomon knots (21), represent challenging synthetic goals that have nevertheless been realized. These molecular compounds are usually synthesized by a template-directed approach (22) that depends on molecular recognition and self-assembly processes.…”

mentioning

confidence: 99%

Efficient production of [ n ]rotaxanes by using template-directed clipping reactions

Leung

Stoddart

2007

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

116

View full text Add to dashboard Cite

In this article, we report on the efficient synthesis of well defined, homogeneous [n]rotaxanes (n up to 11) by a template-directed thermodynamic clipping approach. By employing dynamic covalent chemistry in the form of reversible imine bond formation, [ dynamic covalent chemistry ͉ molecular recognition ͉ polyrotaxanes ͉ self-assembly ͉ template-directed synthesis M echanically interlocked and knotted compounds, such as rotaxanes (1-5), catenanes (6-10), suitanes (11, 12), trefoil knots (13-17), , and Solomon knots (21), represent challenging synthetic goals that have nevertheless been realized. These molecular compounds are usually synthesized by a template-directed approach (22) that depends on molecular recognition and self-assembly processes. Recently, their potential applications as molecular switches for nanoelectronics (23, 24) and molecular actuators for constructing artificial muscles (25), for fabricating smart surface materials (26), and for controlling the nanoscale release of molecules trapped in mesoporous silica (27)(28)(29) were demonstrated. Polyrotaxanes and well defined, homogeneous oligorotaxanes, in which the recognition sites on a dumbbell (an axle terminated by bulky stoppers) are encircled by large rings or macrocycles (wheels) by dint of molecular recognition, have become (30-36) one of the most intensively investigated subjects in mechanical chemistry. A general synthetic method for making rotaxanes, namely, the ''threading-followed-by-stoppering'' approach (Fig. 1, method A), involves (30-32) several macrocycles. First, the macrocycles are threaded onto oligomeric or polymeric axles carrying recognition sites at prescribed intervals along the axles to form pseudorotaxanes, then both ends of the axles are stoppered with bulky groups. Although this approach is relatively simple, it does not provide complete control over the number of threaded macrocycles, that is, the rings or beads are often not threaded onto all of the available recognition sites on the axles. Alternatively, a template-directed ''clipping'' approach (Fig. 1, method B), in which the macrocycles are formed from acyclic precursors in the presence of templating recognition sites on the dumbbells, has provided (33-36) a versatile means for the construction of some lower-order rotaxanes. Nonetheless, the efficient synthesis of well defined, homogeneous, higher-order polyrotaxanes continues to be a challenge to synthetic chemists.Recently, dynamic covalent chemistry (37-40), exemplified by reversible imine formation (41, 42), metal-ligand exchange (43), and olefin metathesis (44, 45), has been demonstrated to be an effective tool for the preparation of various exotic mechanically interlocked molecular compounds. It has been found that, in the presence of an appropriate template, one of the possible compounds in the dynamic library, after mixing the different components, can be amplified to give the thermodynamically most stable product. We have reported (see refs. 46-49) an example of such a template-directed synthesis of ...

show abstract

mentioning

confidence: 99%

Efficient production of [ n ]rotaxanes by using template-directed clipping reactions

Leung

Stoddart

2007

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

116

View full text Add to dashboard Cite

show abstract

“…This example provides an alternative route to the efficient synthesis of various catenanes. Doubly interlocked [2]catenanes, Solomon links, are fascinating synthetic targets because their synthesis is more difficult than that of simple [2]catenanes (Hopf links) [129]. A Solomon link has four crossings, whereas a Hopf link has two crossings.…”

Section: Catenanesmentioning

confidence: 99%

Three-Dimensional Aromatic Networks

Toyota

Iwanaga

2012

Topics in Current Chemistry

View full text Add to dashboard Cite

Three-dimensional (3D) networks consisting of aromatic units and linkers are reviewed from various aspects. To understand principles for the construction of such compounds, we generalize the roles of building units, the synthetic approaches, and the classification of networks. As fundamental compounds, cyclophanes with large aromatic units and aromatic macrocycles with linear acetylene linkers are highlighted in terms of transannular interactions between aromatic units, conformational preference, and resolution of chiral derivatives. Polycyclic cage compounds are constructed from building units by linkages via covalent bonds, metal-coordination bonds, or hydrogen bonds. Large cage networks often include a wide range of guest species in their cavity to afford novel inclusion compounds. Topological isomers consisting of two or more macrocycles are formed by cyclization of preorganized species. Some complicated topological networks are constructed by self-assembly of simple building units.

show abstract

“…[2]-catenanes can be doubly (Ibukuro et al, 1999;Pentecost et al, 2006) or triply or manifold interwoven. Such mechanical bonds with the additional intrinsic intertwinings I propose to call the tight ones, not to mix them with the multiple mechanical bonds (Vysotsky, 2009), since the last ones appear within the structures having the possibility 1) to be disconnected only once; 2) having more than two covalent units, which are mechanically bound together.…”

Section: Normal and Tight Mechanical Bondsmentioning

confidence: 99%

Classification of the Mechanical Bonds

Vysotsky¹

2011

IJC

View full text Add to dashboard Cite

The analysis of suit[2]-, suit [3]ane and tetrafould [2]-rotaxanes on the bases of calix[4]-arene with the help of the "mechanical disconnection operation" show that these structures possess only one mechanical bond, which is suggested to be called bi-, tri-and tetrafurcated one, respectively, since such structures bear two, three and four divergent mechanical entanglements. In the same time, introduction of the external bulky groups to these structures transforms such unique mechanical bonds into several single ones. There can be several different invariants which have only one mechanical bond, but possess different number of the intrinsic mechanical entanglements like, for example, in [2]-catenane and doubly braided [2]-catenane. The mechanical bond in the last case is proposed to be called the tight one. The constrictive bonds in carceplexes are classified as the spherical mechanical bonds. Thus, the whole classification of the mechanical bonds (together with the previously proposed ones), is presented.

show abstract

A Molecular Solomon Link

Abstract: Knots galore: With a judicious choice of ions and solvents, it is possible to amplify a molecular Solomon link by kinetically controlled crystallization from a dynamic combinatorial library of molecular knots (see scheme).

Cited by 251 publications

References 64 publications

Efficient production of [ n ]rotaxanes by using template-directed clipping reactions

Efficient production of [ n ]rotaxanes by using template-directed clipping reactions

Three-Dimensional Aromatic Networks

Classification of the Mechanical Bonds

Contact Info

Product

Resources

About