
%0 Journal Article
%A Kepert, David L. 
%A Junk, Peter C. 
%A Skelton, Brian W. 
%A White, Allan H. 
%T Structural Systematics of Rare Earth Complexes. XIII (&#8216;Maximally&#8217;) Hydrated (Heavy) Rare Earth Nitrates
%J Australian Journal of Chemistry
%D 1999/08/05
%V 52
%N 6
%P 497-506
%K 
%R https://doi.org/10.1071/CH98044
%U https://www.publish.csiro.au/paper/CH98044 
%X Room-temperature single-crystal X-ray structure determinations are known for a number of &#8216;maximally hydrated&quot; nitrates of, in particular, the lighter lanthanoid elements; in all cases, all nitrates coordinate as O,O&#8242;-bidentate ligands so that the series may be represented at the outset as Ln(O2NO)3.x H2O. Two distinct triclinic P 1 hexahydrate phases of similar cell dimensions are recognized, the most distinctive distinguishing feature being that in the La, Ce phase the 11-coordinate Ln is surrounded by three O,O&#8242;-bidentate nitrate and five O-unidentate water molecule ligands; the domain of the other, with four coordinated water molecules, extends from Ln = Pr to Ln = Dy (inclusive of Y). At local ambience, we have crystallized heavier members of the series as pentahydrates, isomorphous with the previously characterized Ln = Eu example, also containing a molecule of the form &#91;Ln(O2NO)3(OH2)4&#93; (with a molecule of water of crystallization), but a different stereoisomer to that found in the Ln = Pr(-)Dy array. Structure determinations are recorded for Ln = Dy, Er, Yb, conventional R on &#124;F&#124; 0&#183;042, 0&#183;034, 0&#183;029 for No = 3858, 3980, 3935 independent &#8216;observed&#8217; (I &#62; 3&#963;(I)) diffractometer reflections. For Ln = Lu a new tetrahydrate phase is described, monoclinic P21/n, a 7&#183;379(7), b 10&#183;364(5), c 14&#183;26(1) &#197;, &#946; 96&#183;09(7)&#176;, Z = 4, R 0&#183;048 for No 2324, together with a new triclinic P 1 trihydrate, a 12&#183;591(4), b 12&#183;144(3), c 7&#183;355(2) &#197;, &#945; 80&#183;22(2), &#946; 77&#183;68(3), &#947; 62&#183;30(2)&#176;, Z = 4, R 0&#183;051 for No 4552. In both of the latter, Lu is nine-coordinate, with three bidentate nitrate groups and three coordinated water molecules; remarkably, the two independent molecules of the asymmetric unit in the triclinic phase are distinct isomers, one having the water molecules fac, derivative of the 10-coordinate array of the Pr(-)Yb series with quasi-3 symmetry, while the other, like that in the monoclinic phase, is mer. 
