G. Sánchez-Sanz, C. Trujillo, I. Alkorta and J. Elguero
Modulation of in:out and out:out conformations in [X.X'.X"] Phosphatranes by Lewis Acids
A theoretical study of the [X.X'.X"]phosphatrane:Lewis acid complexes has been carried out in order to analyze how the in:out and out:out conformations can be modulated by the interaction with Lewis acids. It has been found that in:out structures are more stable in larger systems i.e. in [4.4.3]:X and [4.4.4]:X than in [3.3.3]:X and [4.3.3]:X. The results obtained for the relative energies in conjunction with electron density properties showed that upon complexation, in:out conformers become more stable with the increasing acidity of the corresponding Lewis acid. In fact, the binding energies found for in:out complexes are larger than those obtained for out:out complexes. The complexes with the largest relative energy favoring the in:out structure correspond to those with charged Lewis acids, followed by the complexes with ClF. In all cases, the complexes are cooperative, reaching a maximum value of 168.5 kJ·mol–1 for the [4.3.3]:F+ complex.