Size selective self-sorting in coordination-driven self-assembly of finite ensembles

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Chemical Engineering

Background:

• Coordination-driven self-assembly is a powerful method for constructing complex molecular architectures.
• Controlling the size and shape of self-assembled structures from mixtures remains a significant challenge.

Purpose of the Study:

• To demonstrate size-selective self-sorting in the formation of 2-D polygons and 3-D cages.
• To investigate the role of donor building block size in directing self-assembly.
• To achieve the formation of discrete supramolecular products from complex mixtures.

Main Methods:

• Utilized coordination-driven self-assembly with organoplatinum acceptors and dipyridyl linkers.
• Employed mixtures of molecular "clips" or organoplatinum acceptors with varying linker lengths.
• Characterized self-assembled structures using Nuclear Magnetic Resonance (NMR) spectroscopy and electrospray ionization mass spectrometry (ESI-MS).

Main Results:

• Achieved spontaneous formation of two types of 2-D polygons (rectangular and triangular) of different sizes via self-sorting.
• Successfully synthesized two distinct 3-D supramolecular cages of different sizes by mixing a ditopic acceptor with two different sized tritopic donors.
• Demonstrated that self-sorting is directed by donor building block size and a self-correction mechanism.

Conclusions:

• Size-selective self-sorting is an effective strategy for controlling the outcome of coordination-driven self-assembly.
• The dynamic and thermodynamically driven nature of the process allows for the formation of discrete, well-defined supramolecular structures.
• This approach offers a pathway to precisely engineer complex molecular architectures from intricate mixtures.