Eu3Be22N16O: A Highly Condensed Oxonitridoberyllate

The oxonitridoberyllate Eu3Be22N16O was synthesized from Eu(NH2)(2), Be3N2 and BeO in a W crucible under N-2 atmosphere in a radio-frequency furnace at 1400 degrees C. The crystal structure was solved and refined from X-ray diffraction data (C2/c (no. 15), a=20.620(2), b=8.722(6), c=17.506(2) angstrom, beta=120.782(3)degrees) and confirmed with Rietveld refinement methods as well as lattice-energy calculations (Madelung part of lattice energy, MAPLE). Eu3Be22N16O consists of a rigid network of edge-sharing BeX4 (X=N, O) tetrahedra and trigonal-planar BeN3 units resulting in a high degree of condensation kappa=1.29. The charge of the anionic network is compensated by Eu2+. Magnetic susceptibility measurements exhibit Curie-Weiss behavior above 2 K with an effective magnetic moment of 7.82 mu(B)/f.u., which is in accordance with the theoretical value for Eu-II.

Automated summary

The oxonitridoberyllate Eu3Be22N16O was synthesized at high temperature, with a crystal structure consisting of highly condensed BeX4 tetrahedra and BeN3 units, and the charge of the anionic network compensated by Eu2+. The magnetic susceptibility measurements exhibit Curie-Weiss behavior consistent with the theoretical value for Eu-II.