Molecular Russian dolls

Abstract

The host-guest recognition between two macrocycles to form hierarchical non-intertwined ring-in-ring assemblies remains an interesting and challenging target in noncovalent synthesis. Herein, we report the design and characterization of a box-in-box assembly on the basis of host-guest radical-pairing interactions between two rigid diradical dicationic cyclophanes. One striking feature of the box-in-box complex is its ability to host various 1,4-disubstituted benzene derivatives inside as a third component in the cavity of the smaller of the two diradical dicationic cyclophanes to produce hierarchical Russian doll like assemblies. These results highlight the utility of matching the dimensions of two different cyclophanes as an efficient approach for developing new hybrid supramolecular assemblies with radical-paired ring-in-ring complexes and smaller neutral guest molecules.

Solvent‐Induced Cluster‐to‐Cluster Transformation of Homoleptic Gold(I) Thiolates between Catenane and Ring‐in‐Ring Structures

“…Complexes composed of two or multiple rings interlocked or held together by noncovalent interactions have intrigued supramolecular chemists for decades not only for their unique and fascinating structures, but also for their potential applications in catalysis and molecular machines . In the systems comprising two rings, [2]catenanes featuring interlocked rings (Figure a) have been well explored, whereas the ring‐in‐ring complexes, in which one macrocycle threads through another with their mean planes roughly orthogonal to each other (Figure b), or two different‐sized macrocycles are essentially parallel/coplanar or adopt other orientations forming Russian dolls, a gyroscane, or a ring‐in‐ring rotaxane, remain challenging goals in noncovalent synthesis . Ring‐in‐ring complexes are also key intermediates for the preparation of molecular Borromean rings .…”

“…Ring‐in‐ring complexes are also key intermediates for the preparation of molecular Borromean rings . Up to now, a number of ring‐in‐ring complexes consisting of organic macrocycles– held together by hydrogen bonding (Figure c), donor–acceptor, or host–guest– interactions have been reported, together with some examples of ring‐in‐ring metal complexes, in which the two noninterlocked rings were constructed or held together by metal–ligand coordination bonds (such as M–N (M=Cu, Pd, Ru, Ir, Pt, Zn) and M–O bonds (M=Ru, Ir), for example, Figure d–f) or held together by π–π stacking (Figure d,f) or hydrophobic interactions…”

Evaluation of DFT Methods and Implicit Solvation Models for Anion‐Binding Host‐Guest Systems

“…[3] Supramolecular chemistry draws inspiration from Nature's precise use of noncovalent interactions to control chemical structure and reactivity in molecular recognition, templatedirected synthesis, biomimetics, and selfassembly. [2,[4][5][6][7][8][9] Pioneering work by Cram, [10,11] Lehn, [12][13][14][15] and Pederson [16,17] examined the chemistry of simple molecular hosts such as crown ethers, cryptands, and cavitands, and paved the way for the development of more complex and refined structures. In addition, François Diederich's work on host-guest complexation with synthetic cyclophane receptors in a variety of solvents, including aqueous, played a pivotal role in understanding the important features of molecular recognition such as hydrophobic effect, complementarity, and preorganization.…”

Computational screening for nested organic cage complexes

“…of macrocycle-in-a-macrocycle complexes, [10][11][12][13] including Russian doll concentric porphyrin nanorings, 14 and fullerene/macrocycle complexes. 15,16 Some metal-organic nested cage complexes have been reported; 17 perhaps the most relevant are those complexes that involve the encapsulation of a small organic cage within a metal-organic cage, 18,19 or the formation of multi-layered DNA nanocages.…”