Versatile Inclusion Behaviour of a Dinitrocalix[4]arene Having Two Ester Pendants - Preparation and X-ray crystal Structures of Complexes

Tobias Gruber (1) , Edwin Weber (1) , Wilhelm Seichter (1, 2) , Petra Bombicz (3) , Ingeborg Csöregh (1, 4)

1 Institut für Organische Chemie [Freiberg]
2 TU Bergakademie Freiberg - Technishe Universität Bergakademie Freiberg
3 Structural Chemistry
4 Structural Chemistry

An upper-rim dinitro-substituted calix[4]arene possessing two lower-rim ethyl ester pendant groups (1) has been shown to form solid inclusion compounds with acetone (1:1) (1a), DMF (1:1) (1b), DMSO (1:1) (1c) and n-BuOH (2:1) (1d). X-ray crystal structures of the four complexes 1a-d are reported and comparatively discussed, including isostructurality calculations. Although the solid-state conformation of the dintirocalix[4]arene moiety, stabilized by two intramolecular O-H...O bonds, is maintained in the four inclusion compounds, and all four co-crystals have similar unit cell dimensions and identical space group symmetries, only three of them (1a-c) are homostructural. Depending on the nature of the guest molecule, either the upper or the lower-rim site of the calixarene is involved in the complexation, demonstrating either cavitate- or clathrate-type of supramolecular interactions, respectively. Moreover, due to the different guest recognition modes, the calixarene host in 1d is rotated through a non-crystallographic virtual rotation of 180 within the unit cell, in relation to the host molecules in each of the other three homostructural compounds 1a-c, thus giving rise to supramolecular morphotropism - to our knowledge the first case ever described.

Mots clés: Physical Sciences

Tobias Gruber, Edwin Weber, Wilhelm Seichter, Petra Bombicz, Ingeborg Csöregh. Versatile Inclusion Behaviour of a Dinitrocalix[4]arene Having Two Ester Pendants - Preparation and X-ray crystal Structures of Complexes. Supramolecular Chemistry, 2006, 18 (06), pp.537-547. ⟨10.1080/10610270600847040⟩. ⟨hal-00513481⟩