WRAPPING OXOMETALATES WITH MACROCYCLIC LIGANDS - THE DECAVANADATE-CRYPTAND SYSTEM

Co-crystallisation of tetmethylammonium vanadate and cryptand (C22n) a t pH 5.5 in tetramethoxysilane gel yielded the centro-symmetric sandwi ch compounds [C22n(H+)(2)](2)[H2V10O28] (n = 1 (1); 2 (2)). The proton ation site in dihydrogendecavanadate is mu(3)-O (1) or mu(2)-O (2). In the cryptands. the protons are located at the nitrogen atoms. Cations and anion are mainly connected by electrostatic interaction. In addit ion, in the case of 1, there is a hydrogen bond between the anionic pr otonation site and the cryptand oxygen of one of the diether bridges ( C) 1998 Elsevier Science S.A. All rights reserved.