Host-guest interactions between octa acid and cations/nucleobases.

Area of Science:

• Supramolecular Chemistry
• Computational Chemistry
• Molecular Recognition

Background:

• Host-guest chemistry explores the interactions between host molecules and guest molecules.
• Cavitands, like octa acid (OA), are macrocyclic hosts with unique binding properties.
• Understanding these interactions is crucial for designing new materials and sensors.

Purpose of the Study:

• To investigate the host-guest interactions between octa acid (OA) and various cationic and heterocyclic guests.
• To determine the thermodynamic favorability and selectivity of these binding events.
• To elucidate the nature of noncovalent interactions governing the host-guest complexes.

Main Methods:

• Density Functional Theory (DFT) based computations were employed.
• Thermochemical analysis was performed at 298.15 K and 1 atm.
• Noncovalent interaction and energy decomposition analyses were conducted.

Main Results:

• All examined guests exhibited thermodynamically favorable binding with OA.
• OA demonstrated higher selectivity for lighter cations and specific heterocyclic moieties (adenine, guanine, TTF) over heavier ones or other heterocycles (cytosine, thymine, uracil).
• Van der Waals, electrostatic, and orbital interactions were identified as key forces in host-guest complex formation.

Conclusions:

• Octa acid (OA) is an effective host for specific cations and heterocyclic molecules.
• The binding affinity and selectivity are influenced by the nature of the guest.
• DFT calculations provide valuable insights into the electronic and spectral properties modulated by guest binding.