Modulation of in:out and out:out conformations in [: X. X ′. X ′′] phosphatranes by Lewis acids

A theoretical study of [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 (LA). It has been found that in:out structures are more stable in larger systems i.e. in [4.4.3]:LA and [4.4.4]:LA than in [3.3.3]:LA and [4.3.3]:LA. 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 for the [4.3.3]:F complex.Funding sources: This work was carried out with financial support from the Ministerio de Economia y Competitividad (Project No. CTQ2015-63997-C2-2-P) and Comunidad Autónoma de Madrid (S2013/MIT2841, Fotocarbon). Thanks are also given to the Irish Centre for High-End Computing (ICHEC), and CTI (CSIC) for their continued computational supportPeer Reviewe