Complex formation of Cucurbit[6]uril with DABCO and DABCO derivatives: An experimental and DFT study

The complex formation of Cucurbit[6]uril with DABCO and DABCO derivatives in solution has been studied using calorimetric titrations. For a better understanding of factors influencing the complex formation, several DABCO derivatives have been synthesized. All compounds have been characterized. Inclusion complex formation could not be observed. Even with dumbbell derivatives of DABCO threading through the Cucurbit[6]uril cavity does not occur. As a result, no rotaxanes have been formed in solution. These results are in accordance with DFT calculations.