Modular Cavity‐Tunable Self‐Assembly of Molecular Bowls and Crowns as Structural Analogues of Calix[3]arenes

Abstract

A [3+3] modular self‐assembly gives rise to the formation of a molecular bowl or crown with syn,syn,syn conformation (see picture). These structures are analogues of calix[3]arenes and can function as anion receptors. Interestingly, an NO3− ion is found to distort from a trigonal plane into a trigonal pyramid when binding to the bottom of the molecular bowl.

Cyclic tetranuclear half-sandwich ruthenium(II) complexes with 4,7-phenanthroline and hydroxo bridges: Crystal structure, solution behaviour and binding to nucleosides

“…As shown in the figure, the environment of the Ru centres consist in a g 6 coordinated p-cymene, two N donor atoms from two bridging 4,7-phenanthroline heterocycles and two O donor atoms from two bridging hydroxide anions. The 4,7-phenanthroline ligands bind in the expected N 4 ,N 7 exobidentate bridging mode [9,46] with a concomitant RuÁ Á ÁRu separation of 8.02 Å which defines the longer side of a molecular rectangle of the tetranuclear cations. The two phen ligands stack within the tetranuclear complexes adopting an eclipsed conformation with a mean separation of $3.5 Å between the two aromatic rings.…”

Self‐Assembly of Water‐Soluble Platinum(II)‐Based Metallacalixarenes and Tuning Their Conformational Interconversion via Synergistic Effects between Solvents and Anions

“…Elemental analyses calcd (%) for C 42 H 56 N 16 O 12 Pt 2 :C ,3 6.90;H ,4 .13;N ,1 6.39. Found:C ,3 6.85;H ,4 .16;N ,1 6.44 20,136.86,129.43,128.53,127.13,117.53,110.55,64.45,52.28,51.90,51.16 ppm. For 53, 138.47, 131.07, 127.40, 126.64, 117.33, 111.31, 64.68, 55.61, 52.41, 50 ,36.90;H ,4 .13;N ,1 6.39.…”

“…Amongt hem, some cages and capsules were found to have potentiali ne ncapsulation and cavity-oriented reactions in aqueous media. [19] Since 2003, using metal-directed self-assembly strategies,w es uccessfully synthesized water-soluble Pd II or Pt II -based molecular containers such as metallacalixarene [20] that show promise in anion complexation and sensing, guest encapsulation,a nd so forth. Based upon rational design principles of coordination motifs, [21][22][23] subtle variations in ligand design such as the flexibility [24] were focused, which showed importance not only in affecting the overall structures formed but also for defining the physicochemical characteristics of the resultingc avities.…”

Anion coordination complex [Cl⊂Pt(bpt)4]Cl (bpt=N,N′-bis(3-pyridylmethyl)-2-thiourea)

“…So far, great efforts have been made in the design and synthesis of molecular hosts (artificial receptors) for anionic species [3][4][5][6][10][11][12] . Recently we have reported self-assembly of molecular bowls, crowns, baskets and hats [13][14][15] . Those positive-charged coordination hosts featured with cone conformation are capable of binding mineral anions through electrostatic interactions.…”