Effect of Inclining Strain on the Crystal Lattice along an Extended Series of Lanthanide Hydroxysulfates Ln(OH)SO4 (Ln = Pr鈭扽b, except Pm)

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• 作者：Ralph A. Zehnder ; Christopher S. Wilson ; Hunter T. Christy ; Kenneth S. Harris ; Varun Chauhan ; Victor Schutz ; Matthew Sullivan ; Matthias Zeller ; Frank R. Fronczek ; Jacob A. Myers ; Kyle Dammann ; James Duck ; Peter M. Smith ; Antony Okuma ; Kristin Johnson ; Robert Sovesky ; Cameron Stroudt ; Robert A. Renn
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：February 7, 2011
• 年：2011
• 卷：50
• 期：3
• 页码：836-846
• 全文大小：1172K
• 年卷期：v.50,no.3(February 7, 2011)
• ISSN：1520-510X

文摘

A series of trivalent lanthanide hydroxysulfates, Ln(OH)SO₄, (Ln = Pr through Yb, except radioactive Pm) has been synthesized via hydrothermal methods from Ln₂(SO₄)₃路8H₂O by reaction with aqueous NaOH at 170 掳C in Teflon lined Parr steel autoclaves, and were characterized by single crystal X-ray diffraction and FT-IR spectroscopy. Two types of arrangements were found in the solid state. The lighter (Ln = Pr鈭扤d, Sm鈭扜d) and heavier lanthanide(III) hydroxysulfates (Tb鈭扽b) are each isostructural. Both structure types exhibit the monoclinic space group P2₁/n, but the unit cell content is doubled with two crystallographically distinct LnO₈ polyhedra for the heavier lanthanide compounds. The lighter complexes maintain the coordination number 9, forming a three-dimensional extended lattice. The heavier counterparts exhibit the coordination number 8, and arrange as infinite columns of two crystallographically different LnO₈ polyhedra, while extending along the 鈥?i>c鈥?axis. These columns of LnO₈ polyhedra are surrounded and separated by six columns of sulfate ions, also elongating in the 鈥渃鈥?direction. The rigid sulfate entities seem to obstruct the closing in of the lighter LnO₉ polyhedra, and show an inclining degree of torsion into the 鈥?i>ac鈥?layers. The crystal lattice of the lighter 4f complexes can sufficiently withstand the tension buildup, caused by the decreasing Ln³⁺ radius, up to Gd(OH)SO₄. The energy profile of this structural arrangement then seems to exceed levels at which this structure type is favorable. The lattice arrangement of the heavier Ln-analogues seems to offer a lower energy profile. This appears to be the preferred arrangement for the heavier lanthanide hydroxysulfates, whose crystal lattice exhibits more flexibility, as the coordination sphere of these analogues is less crowded. The IR absorbance frequencies of the hydroxide ligands correlate as a function of the Ln³⁺ ionic radius. This corresponds well with the X-ray single crystal analysis data.