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Observation and isolation of layered and framework ytterbium hydroxide phases using in situ energy-dispersive X-ray diffraction

McIntyre, Laura J.; Prior, Timothy J.; Fogg, Andrew M.

Authors

Laura J. McIntyre

Andrew M. Fogg



Abstract

In situ energy-dispersive X-ray diffraction has been used to investigate the synthesis of the recently reported lanthanide hydroxynitrate phases, Ln 2 (OH) 5 NO 3 ·1.5H 2 O (Ln = Y, Er, Yb). Through control of the reaction temperature, three distinct layered phases with differing degrees of hydration (x = 1 (1), 1.5 (2), and 2 (3)) were observed in the Yb synthesis and subsequently isolated. Only the phase with x = 1.5 was observed for the reactions with Y and Er. The crystal structures of Yb 2 (OH) 5 NO 3 2H 2 O (2) and Yb 2 (OH) 5 NO 3 H 2 O (3) were determined in a single-crystal diffraction study and represent the first crystal structures of the new lanthanide hydroxynitrate phases. Both Yb 2 (OH) 5 NO 3 ·2H 2 O and Yb 2 (OH) 5 NO 3 ·H 2 O adopt orthorhombic structures in which the nitrate anion is coordinated to the Yb 3+ cations within the hydroxide layer and are largely resistant to anion exchange. This is in contrast to the Ln 2 (OH) 5 NO 3 ·1.5H 2 O phases, which undergo facile anion exchange reactions at room temperature, indicating that the nitrate resides in the interlayer gallery. At temperatures above 200 °C, the three layered phases were determined to be intermediates in the synthesis of Yb 4 O(OH) 9 NO 3 (4), which has a framework structure with the uncoordinated nitrate anions located in one-dimensional channels. The in situ diffraction technique has allowed for a detailed kinetic and mechanistic investigation of the synthesis and revealed that the layered ytterbium hydroxynitrate phases form via a two-dimensional phase boundary-controlled growth mechanism. It was also possible to estimate the activation energies for the hydrothermal synthesis of Yb 2 (OH) 5 NO 3 ·H 2 O and Yb 2 (OH) 5 NO 3 ·2H 2 O from basic solution, as +29 and +67 kJ/mol, respectively. © 2010 American Chemical Society.

Citation

McIntyre, L. J., Prior, T. J., & Fogg, A. M. (2010). Observation and isolation of layered and framework ytterbium hydroxide phases using in situ energy-dispersive X-ray diffraction. Chemistry of materials : a publication of the American Chemical Society, 22(8), 2635-2645. https://doi.org/10.1021/cm1000208

Journal Article Type Article
Online Publication Date Mar 4, 2010
Publication Date Apr 27, 2010
Deposit Date Nov 13, 2014
Publicly Available Date
Journal Chemistry Of Materials
Print ISSN 0897-4756
Electronic ISSN 1520-5002
Publisher American Chemical Society
Peer Reviewed Peer Reviewed
Volume 22
Issue 8
Pages 2635-2645
DOI https://doi.org/10.1021/cm1000208
Keywords Materials Chemistry; General Chemistry; General Chemical Engineering
Public URL https://hull-repository.worktribe.com/output/460707
Publisher URL https://pubs.acs.org/doi/abs/10.1021/cm1000208