Self-assembly of a supramolecular hexagram and a supramolecular pentagram

Abstract

Five- and six-pointed star structures occur frequently in nature as flowers, snow-flakes, leaves and so on. These star-shaped patterns are also frequently used in both functional and artistic man-made architectures. Here following a stepwise synthesis and self-assembly approach, pentagonal and hexagonal metallosupramolecules possessing star-shaped motifs were prepared based on the careful design of metallo-organic ligands (MOLs). In the MOL design and preparation, robust ruthenium–terpyridyl complexes were employed to construct brominated metallo-organic intermediates, followed by a Suzuki coupling reaction to achieve the required ensemble. Ligand LA (VRu2+X, V=bisterpyridine, X=tetraterpyridine, Ru=Ruthenium) was initially used for the self-assembly of an anticipated hexagram upon reaction with Cd2+ or Fe2+; however, unexpected pentagonal structures were formed, that is, [Cd5LA5]30+ and [Fe5LA5]30+. In our redesign, LB [V(Ru2+X)2] was synthesized and treated with 60° V-shaped bisterpyridine (V) and Cd2+ to create hexagonal hexagram [Cd12V3LB3]36+ along with traces of the triangle [Cd3V3]6+. Finally, a pure supramolecular hexagram [Fe12V3LB3]36+ was successfully isolated in a high yield using Fe2+ with a higher assembly temperature.

Multicomponent Self‐Assembly of Metallo‐Supramolecular Macrocycles and Cages through Dynamic Heteroleptic Terpyridine Complexation

“…Although the <tpy‐Fe II /Ru II ‐tpy>‐based metallo‐ligand approach has been ubiquitously utilized in construction of metallo‐supramolecules,–,, the resultant complexes emit practically nothing at room temperature because of the short lifetime of the metal‐to‐ligand charge transfer (MLCT) excited states . In contrast, <tpy‐Zn II /Cd II ‐tpy>‐based derivatives preserve the ligand‐based luminescence owing to the filled d 10 shell of the metal ions .…”

Constructing High‐Generation Sierpiński Triangles by Molecular Puzzling

“…Coordination‐driven supramolecular chemistry in solution may provide an alternative approach to obtain different generations of Sierpiński triangles in a precisely controlled manner. Newkome and co‐workers reported the terpyridine (tpy) based molecular Sierpiński metallo‐triangle G2, which was assembled based on a 60°‐oriented bis(terpyridine) V with a 60° bite angle, 1,2,3,4‐tetra(terpyridine) K , and Cd II .…”

Multi‐Component Spirane Assemblies

“…Spirane‐like structures are contained as a submotif in the amazing hexagram and pentagram assemblies of Newkome . An intricate and impressive trispirane assembly was made equally by Newkome using complexation of ruthenium(II) and terpyridine in a stepwise approach inspiring many related architectures . However, following the nomenclature in its strictest interpretation, spiranes are twisted structures ( spīra , gr.…”