Jean-Paul Declercq

Supramolecular Assemblies of Phosphorylated Cavitands

The recent results in the chemistry of cavitands have proved that they are very efficient molecular receptors and potential precursors of molecular devices. In this context, we have investigated the synthesis and binding properties of phosphorylated cavitands. The stereoselective synthesis and the structural studies of the new compounds showed that these bowl-shaped molecules possess a well defined aromatic cavity surrounded by four phosphoryl groups (P=O or P=S). They are very efficient ligands for metal and organic cations. They are able to encapsulate cationic species by cooperative effect of the preorganized aromatic cavity and the four phosphorylated groups. Moreover, the upper and lower rim functionalitics can lead to the formation of molecular capsules and supramolecular assemblies whose properties and structures have been investigated by X-ray diffraction and NMR studies in solution.

A (2R,5S)‐2‐o‐anisyl‐3‐oxa‐1‐aza‐2‐phosphabicyclo[3.3.0]octane–borane complex

(2R,5S)-2-(2-Methoxyphenyl)-3-oxa-1-aza-2-phos-phabicyclo[3.3.0]octane(P-B)borane, C12H19BNO2P, is one of a series of new chiral oxazaphospholidine-borane complexes used as catalysts in the enantioselective borane reduction of ketones. The structure and the absolute configuration about the P atom were determined.

Structures of two crown-ether derivatives of 9-acridone

(I) N-Methyl-2,5,8,11,14,17,20-heptaoxa-25-azatetracyclo[19.7.5.0(24,32),0(26,30)]tritriaconta-1 (29),-21(33),22,24(32),26(30),27-hexaen-31-one trihydrate, C26H33NO8.3H2O, M(r) = 541.6, triclinic, P1BAR, a = 7.389 (1), b = 13.255 (1), c = 14.448 (2) angstrom, alpha = 88.60 (1), beta = 78.58 (1), gamma = 81.48 (1)-degrees, V = 1371.7 (2) angstrom 3, Z = 2, D(x) = 1.31 g cm-3, lambda(Cu K-alpha) = 1.54178 angstrom, mu = 8.68 cm-1, F(000) = 580, T = 291 K, R = 0.047 for 3376 observed reflections. (II) N-Methyl-2,5,8,11,14,17-hexaoxa-22-azatetracylco[16.7.5.0.(21,29).0(23,27)]triaconta-1 (26), 18(30), 19,-21(29),23(27),24-hexaen-28-one, C24H29NO7, M(r) = 443.5, triclinic, P1BAR, a = 8.426 (2), b = 11.420 (2), c = 11.739 (4) angstrom, alpha = 87.20 (3), beta = 79.33 (3), gamma = 77.88 (2)-degrees, V = 1085.3 (5) angstrom 3, Z = 2, D(x) = 1.36 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 1.08 cm-1, F(000) = 472, T = 291 K, R = 0.039 for 3229 observed reflections. In these substituted acridone derivatives one molecule contains both a crown ether moiety with its complexing capabilities and a heterocyclic N atom able to modify these properties. In the two compounds, the crown ether chain is nearly perpendicular to the acridinic skeleton which is planar. In (I) the water molecules take part in hydrogen bonds with the crown ether [O37...O11 = 3.03 (1), O35...O36 = 2.81 (1) angstrom] and with each other [O36...O37 = 2.93 (1), O38...O36 = 2.84 (1), O38...O37 (x + 1, y, z) = 2.89 (1) and O38...O37 (1 - x, 1 - y, 1 - z) = 2.88 (1) angstrom]. The bond lengths suggest partial localization of double bonds in the benzene rings.