Interrogating the Interplay between Hydrogen and Halogen Bonding in Graphitic Carbon Nitride Building Blocks

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Computational Chemistry

Background:

• Graphitic carbon nitride (g-C3N4) is a versatile material with potential in self-assembly.
• Halogen bonding is a key non-covalent interaction for molecular recognition and materials design.
• Understanding the assembly of g-C3N4-based systems is crucial for developing novel functional materials.

Purpose of the Study:

• To computationally evaluate two novel g-C3N4 molecular building blocks for halogen bond-driven assembly.
• To investigate the formation and characteristics of donor-acceptor complexes involving these g-C3N4 units.
• To analyze the role of intermolecular hydrogen bonding in these complexes.

Main Methods:

• Computational quantum chemistry calculations were employed.
• Analysis of halogen bond formation sites and complex stoichiometry (1:1, 2:1, 3:1).
• Investigation of intermolecular hydrogen bonding, binding energies, and vibrational frequencies.

Main Results:

• Two g-C3N4 acceptors with three unique halogen bond sites were identified.
• Formation of 1:1, 2:1, and 3:1 donor-acceptor complexes was observed.
• Intermolecular hydrogen bonding was prominent with iodine-based donors, leading to significant binding energies up to -26.5 kcal mol⁻¹.
• Vibrational frequencies were analyzed and compared to related systems.

Conclusions:

• The designed g-C3N4 building blocks effectively participate in halogen bond-driven self-assembly.
• The interplay of halogen and hydrogen bonding dictates complex stability and structure.
• These findings provide insights into designing advanced supramolecular architectures using g-C3N4.