A structural study of the interaction of dibenzyldiaza-18-crown-6 with neodymium(III) nitrate hexahydrate

The structure of the complex salt, [C26H40N2O4][Nd(NO3)(5)(H2O)] (1), was determined by single crystal X-ray diffraction. It consists of alternating layers of the anionic complex, [Nd(NO3)(5)(H2O)](2-)(,) and the cationic diprotonated [2H.azacrown] (2+). The Nd3+ complex anion is coordinated to five bidentate nitrate ligands and a water ligand to give an 11-coordinated environment. Each Nd moiety is linked to another through intermolecular hydrogen bonding to form pairs of Nd moieties. The azacrown adopts a chair conformation and the benzyl groups are attached to the nitrogen atoms in an anti position with respect to each other, above and below the plane of the macro-ring in agreement with the conformation of the uncomplexed protonated azacrown as obtained by the PM3 method. (C) 1998 Elsevier Science B.V. All rights reserved.