Resorcarene-Based Nanoarchitectures: Metal-Directed Assembly of a Molecular Loop and Tetrahedron

Abstract

Large cavities and portals are present in the nanoscale molecular architectures formed from dithiocarbamate-functionalized resorcarene ligands and zinc(II) or copper(III) ions. With Zn(II) a molecular loop based on a triangle of resorcarene cups is prepared-the cavity is circular (shown on the left). A molecular cage based on a distorted tetrahedron of four resorcarene ligands assembled by eight Cu(III) ions contains triangular-shaped portals suitable for guest passage (shown on the right).

A Structural Survey of Poly-Functional Dithiocarbamate Ligands and the Aggregation Patterns They Sustain

“…There is an isomorphous relationship between 43 and 44. The tetrakis dithiocarbamate ligand based on four resorcarene ligands, L 11 , in neutral Zn6(L 11 )3 in 43 [45] was observed previously in the [Cu8(L 11 )4] 8+ octa-cation of 27, as shown in Figure 6c. However, in 43, a different arrangement in the hexa-nuclear cluster is noted.…”

“…The core of the cluster is a distorted Cu 4 tetrahedron disposed about a 2-fold axis of symmetry. The final copper structure to be described reverts to square-planar copper(III) centres in octanuclear [Cu 8 (L 11 ) 4 ] 8+ of (27), which were developed for host-guest chemistry [45]. The octacationic species has S 4 symmetry and features four resorcarene ligands, each functionalised with four dithiocarbamate residues, with each residue chelating a copper(III) centre, as detailed in Figure 6b.…”

Copper Dithiocarbamates: Coordination Chemistry and Applications in Materials Science, Biosciences and Beyond

“…As discussed in the preceding section, [Cu(S2CNR2)2] have a relatively low oxidation potential [78]; hence, the addition of a range of oxidising agents results in the formation of the analogous Cu(III) complexes. Common oxidants used are I2 [79][80][81], The addition of CuCl 2 to [Cu(S 2 CNR 2 ) 2 ] leads to ligand redistribution and the formation of dimeric [Cu(S 2 CNR 2 )(µ-Cl)] 2 [65][66][67], a crystal structure of [Cu(S 2 CNEt 2 )(µ-Cl)] 2 confirming its identity. It consists of weakly associated dimers being held together by intermolecular Cu-C1 (2.874 Å) and Cu-S (2.882 Å) interactions [65].…”

“…As discussed in the preceding section, [Cu(S 2 CNR 2 ) 2 ] have a relatively low oxidation potential [78]; hence, the addition of a range of oxidising agents results in the formation of the analogous Cu(III) complexes. Common oxidants used are I 2 [79][80][81], (NO)BF 4 [82], InI 3 [83] ] is very fast (k e = 3 × 10 8 M −1 •sec −1 at 298 K). This has prompted a mechanism to be put forward that invokes the formation of an iodide-bridged intermediate, in which electron-density is delocalised across both copper centres and the bridging iodine(s).…”

Site-Specific Metal Chelation Facilitates the Unveiling of Hidden Coordination Sites in an FeII/FeIII-Seamed Pyrogallol[4]arene Nanocapsule

“…The design of metal-organic supramolecular structures with well-defined shapes and dimensions continues to attract intense interest, a primary reason being their ability to mimic biologically active sites. [1][2][3][4][5][6][7][8] These inorganic-organic hybrids are typically formed by the metal-directed assembly of suitably functionalized organic ligands, [9][10][11][12][13][14][15][16][17] and recent years have witnessed the synthesis of such species with paramagnetic metal ions; this is a popular strategy due to the inherent potential for one to control or influence the resulting magnetic properties of a system. 9,[18][19][20][21][22][23][24] Our efforts to synthesize such supramolecular hybrids primarily utilize C-alkylpyrogallol [4]arenes (PgCn, where n is the number of carbon atoms in pendant alkyl chains) as organic ligands.…”