We investigated the threading of bis(benzimidazolium) methane moieties with DB24C8 at 35°C (room temperature) and found a high degree of association. The presence of threaded complexes was determined by 1H NMR and also supported by high resolution mass spectrometry and B3LYP/6- 31G**++calculations. A 2D NMR study was done to elucidate the host-guest geometry and the molecular interactions present. The variable temperature NMR experiment was done over a temperature range of 243-323 K. The threading was stable and visible even at 323 K. Acid-base equilibrium established the reversibility of the process. DFT optimized structures establish that two H-bonded links are present between O 1⋯O 4′ and O 3⋯O 2′ across the dibenzo axis of the crown.
All Science Journal Classification (ASJC) codes
- Drug Discovery
- Organic Chemistry