Russian-Doll-Like Molecular Cubes

Abstract

Nanosized cage-within-cage compounds represent a synergistic molecular self-assembling form of three-dimensional architecture that has received particular research focus. Building multilayered ultralarge cages to simulate complicated virus capsids is believed to be a tough synthetic challenge. Here, we synthesize two large double-shell supramolecular cages by facile self-assembly of presynthesized metal−organic hexatopic terpyridine ligands with metal ions. Differing from the mixture of prisms formed from the inner tritopic ligand, the redesigned metal−organic hexatopic ligands bearing high geometric constraints that led to the exclusive formation of discrete double-shell structures. These two unique nested cages are composed of inner cubes (5.1 nm) and outer huge truncated cubes (12.0 and 13.2 nm) with six large bowl-shape subcages distributed on six faces. The results with molecular weights of 75 232 and 77 667 Da were among the largest synthetic cage-in-cage supramolecules reported to date. The composition, size and shape were unambiguously characterized by a combination of 1 H NMR, DOSY, ESI-MS, TWIM-MS, TEM, AFM, and SAXS. This work provides an interesting model for functional recognition, delivery, and detection of various guest molecules in the field of supramolecular materials.

Multidimensional Mass Spectrometry Assisted Metallo-Supramolecular Chemistry

“…97 Such a new strategy has been intensively applied in building up a great number of metallo-supramolecular architectures, including supramolecular nut, 98 pentagram and hexagram stars, 99 Sierpiński triangles (Pascal triangles), 21,100 snowflakes, 87 giant cubes, etc. 34 Page 23 of 58 CCS Chemistry…”

“…1 Among various noncovalent driving forces, metal-ligand coordination plays a vital role in the self-assembly of metallosupramolecules with both structural and functional sophistication, benefitting from the high directionality and predictable feature of coordination bonds. [2][3][4][5][6] As a result, metallo-supramolecular chemistry has witnessed an explosion in building up a myriad of artificial supramolecular architectures, including polygons, [7][8][9][10][11] knots, [12][13][14][15] links, [16][17][18][19] fractals, [20][21][22] as well as Platonic, [23][24][25][26][27] Archimedean, [28][29][30][31][32][33][34] and Goldenberg polyhedrons, 35,36 etc. And these complexes show great potentials among different fields, including catalysis, [37][38][39][40][41][42][43][44][45][46] nano-elect...…”

Terpyridine‐Based 3D Discrete Metallosupramolecular Architectures

“…Very recently the Wang group constructed huge double‐shell metallosupramolecular cages by the self‐assembly of pre‐synthesized metallo‐organic hexatopic tpy ligands ( L30 and L31 ) with Zn(II) ( Figure ). [ 100 ] The use of rationally designed metallo‐organic hexatopic ligands that were prepared according to the stepwise synthetic approach could effectively prevent the generation of undesired prisms. The obtained Russian‐doll‐like cubes S43 and S44 had a molecular weight of 77 kDa and possessed a size up to 13.2 nm, as evidenced by a series of characterization techniques including NMR, ESI‐MS, TWIM‐MS, SAXS, TEM, and AFM.…”

Tetratopic Terpyridine Building Unit as a Precursor to Wheel-Like Metallo-Supramolecules

“…Self-assembly is a bottom-up approach to construct architectures with distinct sizes and shapes in the supramolecular fields. , The construction of a variety of supramolecular systems is expected to produce functional materials, which is still an important topic in the field of coordination chemistry due to vast potential applications, such as photo/electric chemistry, − catalysis, − sensing, − and many other fields. − The metal-directed self-assembly of many attractive architectures, such as two-dimensional (2D) supramolecular polygons, − ring-in-rings, , knots, − and three-dimensional (3D) nanocages, − requires efficient synthetic methods for multitopic ligand preparation. − In the last few decades, supramolecular chemists have developed a class of “molecular library” and “combinatorial library,” which enable one to think about how best to implement the geometry of particular molecular architectures. When using a single angular orientation building block, self-assembly generally generates macrocyclic objects which represent oligomers (n-mers). ,, In addition, the multicomponent self-assembly based on multitopic ligands could result in interesting architectures with increasing complexity and functionality; however, the control of the purity and validity of target products in a multicomponent self-assembly system is especially challenging since each component was able to influence the ultimate results. − …”