Yttrium carbonate hydroxide

Abstract

YOHCO3, or thorhombic, P212~2~; a = 4.809 (1), b=6 .957 (l), c=8 .466 (1) A; Z = 4 , de= 3.89 g c m -a. The final R for 737 reflections was 0.0518. The carbonate-group distances and angles are C-O(1) 1.288 (9), C-O(2) 1.279 (9), C-O(3) 1-287 (8) A, O(1)-C-O(2) 122.8 (7), O(1)-C-O(3) 118-7 (6), and O(2)-C-O(3) 1183 (7) °. The carbonate ion is bidentate to two different Y atoms. The distortion in the angles of the carbonate is at tr ibuted to this bonding scheme. The Y atoms' coordinat ion is a monocapped square ant ipr ism with two hydroxyls and seven carbonate oxygens surrounding the Y. Introduction. Commercia l ly available yt t r ium carbonate powder was placed in a 9 % solution of NH4CI saturated with CO2. The solution was then heated in a hydrothermal reactor for 7 d at 360°C and 750 atm. Intensity data were collected on a Syntex P21 automated diffractometer with Mo K~ X-radiat ion and a graphite monochromator (2=0.71069 A). A set of 737 unique reflections with I > 3owas obtained with 20_< Fig. 1. Drawing of the coordination polyhedron of Y in YOHCOa. One of the bidentate carbonates projecting towards the reader has been omitted for clarity. 70 ° . An absorpt ion correction was applied, the crystal being approximated as a non-reentrant polyhedron with p = 208.5 cm -1. Transmission factors varied from 0.35 to 0.71. The structure was solved with the Patterson function and refined anisotropically with full-matrix least squares to a conventional R=0.0518. Atom coordinates and thermal parameters are listed in Table 1. Interatomic distances less than 3.0 A and angles in the carbonate ion are listed in Table 2.* * A list of structure factors has been deposited with the British Library Lending Division as Supplementary Publication No. SUP 31920 (8 pp.). Copies may be obtained through The Executive Secretary, International Union of Crystallography, 13 White Friars, Chester CH1 1NZ, England. Table 2. Bond distances (t~) and angles (0) Symmetry code (a) x, y, z (b) k x , y , k+z Y-O(1) (a) 2-430 (7) (c) 2.430 (7) (d) 2943 (8) Y-O(2) (d) 2470 (6) (d) 2463 (6) Y-O(3) (a) 2.478 (6) (d) 2616 (7) (e) 2.615 (6) Y-O(4) (d) 2.236 (6) (a) 2.252 (5) (c) k+x, k y , z (d) x , k+y, k z O(1)-O(4) (d) 2.895 (9) (c) 2-976 (9)