Columnar Organization of Head-to-Tail Self-Assembled Pt₄ Rings

Abstract

Coordination of Pt(2+) to a family of tunable Schiff base proligands directs the 12-component self-assembly of disk-shaped Pt(4) rings in a head-to-tail fashion. Aggregation of these S(4) symmetric Pt(4) macrocycles into columnar architectures was investigated by dynamic and static light scattering, NMR spectroscopy, powder X-ray diffraction, and transmission electron microscopy. Data from these experiments support the formation of columnar architectures for all of the structures studied except when bulky tris(4-tert-butylphenyl)methyl substituents were present. In this case, aggregation was limited to dimers in CHCl(3) (K(dim) = 3200 +/- 200 L mol(-1) at 25 degrees C) and a thermodynamic analysis revealed that dimerization is an entropy driven process. Columnar architectures of Pt(4) rings with branched 2-hexyldecyl substituents organize into lyotropic mesophases in nonpolar organic solvents. These new self-assembled supramolecules are promising candidates to access nanotubes with multiple linear arrays of Pt(2+) ions.

Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons

“…Therefore, we designed small molecular building blocks whose self-assembly, electrochemical and magnetic properties may be easily fine-tuned with the ultimate aim to form interconnected networks at the nano/microscale level. To meet this challenging task, we set out to use mono-and bimetallic complexes based on readily available Schiff base ligands, which show structural modularity and thus easy fine tuning of their self-assembly properties [26][27][28] . In a recent contribution 29 , we reported on the extremely strong self-assembly behaviour of bimetallic bis-Schiff base complexes incorporating aldimine fragments.…”

Polymerization of a divalent/tetravalent metal-storing atom-mimicking dendrimer

“…Additionally, the Kratky plot of the MALS measurement had a linear slope that suggests formation of an anisotropic chain (fig. S20) ( 36 – 39 ). The dynamic light-scattering (DLS) measurement at a similar concentration (fig.…”

Sterically‐Limited Self‐Assembly of Pt4 Macrocycles into Discrete Non‐covalent Nanotubes: Porous Supramolecular Tetramers and Hexamers

“…[17] We recently reported the head-to-tail self-assembly of Pt 4 macrocycles that organize into non-covalent nanotubes and further self-assemble into nematic and columnar lyotropic mesophases. [18] Here, we describe a method for controlling Abstract: We report a template-free strategy based on steric repulsion for the isolation of discrete columnar aggregates of macrocycles. Specifically, introduction of sterically-demanding trityl-derived substituents at the periphery of Pt 4 Schiff base macrocycles limits the otherwise infinite one-dimensional columnar aggregation to discrete tetrameric and hexameric assemblies.…”