Building inorganic supramolecular architectures using principles adopted from the organic solid state

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Crystallography

Background:

• Developing predictable methods for constructing coordination complexes into specific architectures is crucial.
• Ligands that can simultaneously coordinate metals and form hydrogen bonds offer potential for controlled supramolecular assembly.

Purpose of the Study:

• To present a versatile strategy for assembling coordination complexes into architectures with defined dimensionality.
• To investigate the use of ligands with simultaneous metal coordination and self-complementary hydrogen bonding for reproducible supramolecular synthesis.

Main Methods:

• Synthesis of cadmium(II) coordination polymers using three specific ligands: 2(1H)-pyrazinone, 4(3H)-pyrimidinone, and 4(3H)-quinazolinone.
• Crystallographic characterization of nine resulting coordination compounds.
• Analysis of intermolecular N-H⋯O hydrogen bonds driving assembly.
• Computational analysis using molecular electrostatic potential surfaces to rationalize molecular recognition.

Main Results:

• The chosen ligands consistently provided the necessary synthetic vectors for Cd(II) coordination polymers.
• Supramolecular synthesis was reproducible and insensitive to steric/geometric demands of counterions.
• Directional N-H⋯O hydrogen bonds drove the assembly of building blocks into predictable topologies.
• The synthetic protocol proved robust, yielding the same structural outcome from solution or liquid-assisted grinding.

Conclusions:

• A transferable and practical strategy for the assembly of coordination complexes into specific dimensional architectures has been established.
• The use of ligands with dual functionality (metal coordination and hydrogen bonding) enables predictable and robust supramolecular synthesis.
• Understanding molecular recognition events through electrostatic potential surfaces aids in rationalizing the observed structures.