Theoretical design and simulation of supramolecular polymer unit based on multiple hydrogen bonds

Area of Science:

• Computational chemistry
• Molecular modeling
• Supramolecular chemistry

Background:

• Deazapterin derivatives are heterocyclic ureas with potential biological applications.
• Understanding the self-assembly and stability of deazapterin dimers is crucial for their application.
• Protomeric conformers (b, c) of deazapterin offer diverse structural possibilities for dimer formation.

Purpose of the Study:

• To investigate the stability and structural characteristics of deazapterin dimers.
• To explore the influence of substituents and solvent effects on dimer formation.
• To assess the potential of deazapterin dimers for experimental applications.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to study dimer stability.
• Topological analyses were used to identify intermolecular and intramolecular hydrogen bonds.
• Frequency investigations examined vibrational shifts of hydrogen bonds.
• Solvent effect computations simulated dimerization in various solvent polarities.
• UV-visible spectral differences between monomers and dimers were analyzed.

Main Results:

• The homodimer of deazapterin conformer b exhibited superior stability compared to other configurations.
• Both intermolecular and intramolecular hydrogen bonds were confirmed through topological analyses.
• Hydrogen bonds displayed significant red shifts in stretching vibrational frequencies.
• Electron-donating substituents enhanced the free energy of dimer formation.
• Dimerization is favored in weakly polar solvents like toluene and chloroform.
• UV-visible spectra showed distinct absorption wavelength differences between monomers and dimers.

Conclusions:

• Deazapterin conformer b homodimers are particularly stable.
• The presence and nature of hydrogen bonds significantly influence dimer stability and properties.
• Substituent effects and solvent polarity play key roles in deazapterin dimerization.
• Deazapterin dimers show potential for experimental identification of intermolecular hydrogen bonds and association constants.