ISSN:
0044-2313
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
New Compounds of the M3Ln10O18-Type (M = Ba + Ca; Ln = Sc + Yb, Ho + Y, La + Y). A Contribution about the Occupation of the Octahedra Network and Tunnel StructureThe compounds (I): BaCa2Sc5Yb5O18, (II): BaCa2Ho5Y5O18 and (III): BaCa2La5Y5O18 were prepared and investigated by single crystal X-ray technique. I-III crystallizes in the space group C66—P63, Z = 2. I: a = 17.138; c = 3.217 Å; II: a = 17.765; c = 3.377 Å; III: a = 18.000; c = 3.446 Å. The biggest tunnels of the [Ln9O18]6- network are occupied by Ba2+ the smaller one by Ca2+ and Ln3+ in statistical distribution. Ln3+ on the tunnel positions are I: Yb3+, II: Ho3+ and III: La3+. Considering the comparable radii of Ho3+ and Y3+ the f-orbitals of Ho3+ probable the reason of occupying the tunnel positions with rare earth elements.
Notes:
Die Oxide (I) BaCa2Sc5Yb5O18, (II) BaCa2Ho5Y5O18 und (III) BaCa2La5Y5O18 wurden einkristallin dargestellt und mit Röntgenmethoden untersucht. Sie kristallisieren in der Raumgruppe C66—P63 mit Z = 2. I: a = 17,138; c = 3,217 Å; II: a = 17,765; c = 3,377 Å; III: a = 18,000; c = 3,446 Å. Ba2+ besetzt die großen, Ca2+ mit Ln3+ die kleinen Tunnel des [Ln9O18]6--Oktaedergerüsts. Ln3+ auf Tunnelpositionen ist in I: Yb3+, in II: Ho3+ und in III: La3+. Bei Radiengleichheit von Ho3+ und Y3+ entscheiden vermutlich die f-Orbitale zugunsten der Tunnelbesetzung.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19905890110
