Studies on crown ether complexes—XXVIII. Synthesis, characterization and structure of the complexes of heavier lanthanide nitrates (Gd-Lu) with dibenzo-24-crown-8

Abstract

The heavier lanthanide nitrate complexes with dibenzo-24-crown-8 (DB24C8) have been prepared in acetonitrile. These new complexes with the general formula [Ln(NO 3) 3(OH 2) 3]·(DB24C8) (Ln = Gd-Lu) have been characterized by means of elemental analysis, IR spectra, 1H NMR spectra and conductivity measurements. The crystal and molecular structure of [Gd(NO 3) 3(OH 2) 3]·(DB24C8) has been determined by single-crystal X-ray diffraction. The gadolinium(III) ion is coordinated to the six oxygen atoms of three bidentate nitrate groups and three water molecules. The crown ether molecule is hydrogen bonded to these three water molecules. The average GdO(nitrate) and GdO(water) distances are 2.464(4) and 2.388(3) Å, respectively. The average O(water)⋯O(crown ether) separation is 2.787 Å. The coordination polyhedron is a distorted tricapped trigonal prism.