Coordination chemistry and structure characterization of C 18H 36O 6N 2Eu 2(NO 3) 6·H 2O

Abstract

The crystal structure of a cryptate complex of europium, C 18H 36O 6N 2Eu 2(NO 3) 6·H 2O, has been determined from three-dimensional single-crystal X-ray diffraction data collected on a computer-automated diffractometer. The compound crystallizes in the triclinic space group P l with unit cell dimensions a = 14.815(5), b = 8.828(2), c = 13.302(4) Å, α = 91.57(2), β = 92.64(3), γ = 86.90(3)° and Z = 2. The structure was solved by a heavy atom method and refined by a blocked-matrix least-squares procedure to a conventional R index of 0.029 for 5422 reflections. The molecule is composed of cations (C 18H 36O 6EuNO 3) 2+ and anions [Eu(NO 3) 5· H 2O] 2−. In the cation, the europium(III) ion enclosed in a [2.2.2] molecule is coordinated with eight oxygen and two nitrogen atoms, forming a 10-coordinate complex ion (cryptate), while the other europium(III) ion is bonded to eleven oxygen atoms in the anion.