A molecule based on polyoxometalate acid and crown ether: synthesis and characterization of [(H3O)(C20H24O6)](2)[HPMO12O40]center dot C20H24O6 center dot 3MeCN center dot H2O (C20H24O6 = dibenzo-18-crown-6)

摘要

The new molecule based on 12-molybdophosphate acid and dibenzo-18-crown-6, [(H3O)(C20H24O6)](2)[HPMo12O40]-C(20)H(24)O(6)(.)3MeCN(.)H(2)O 1, was synthesized in acetonitrile and characterized by elemental analyses, IR, H-1 NMR, electrospray mass spectra and single crystal X-ray diffraction, indicating that it contains [(H3O)(dibenzo-18-crown-6)](+) cations, where oxonium. ions are out of the planes defined by crown ether oxygen atoms, and disordered PMo12O403- anions with alpha-Keggin structure where the crystal has high lattice energy so that it is difficult to dissolve it. The crystallographic disorder averages Mo-Mo distances and Mo-O-b/c-Mo angles between the M-3 triplets and within the A triplet. The interactions between crown ether molecules and oxonium ions are hydrogen-bonding with the O(crown ether)-OH3+ distances of 2.510(10)-2.783(7) Angstrom. The interactions between [(H3O)(dibenzo-18-crown-6)](+) cations and PMo12O403- anions are dominantly electrostatic. The electrical conductivity is <10(-7) S.cm(-1). (C) 2002 Elsevier Science B.V. All rights reserved. [References: 31]