Ammonia uptake and release in the MnX₂–NH₃ (X = Cl, Br) systems and structure of the Mn(NH₃)nX₂ (n = 6, 2) ammines

Reardon, H., Hanlon, J. M., Grant, M., Fullbrook, I. and Gregory, D. H. (2012) Ammonia uptake and release in the MnX₂–NH₃ (X = Cl, Br) systems and structure of the Mn(NH₃)nX₂ (n = 6, 2) ammines. Crystals, 2(4), pp. 193-212. (doi:10.3390/cryst2020193)

Abstract

Hexa-ammine complexes, Mn(NH₃)₆X₂ (X = Cl, Br), have been synthesized by ammoniation of the corresponding transition metal halide and characterized by Powder X-ray diffraction (PXRD) and Raman spectroscopy. The hexa-ammine complexes are isostructural (Cubic,Fm-3m, Z = 4; a = 10.2742(6) Å and 10.527(1) Å for X = Cl, Br respectively). Temperature programmed desorption (TPD) demonstrated that ammonia release from Mn(NH₃)₆X₂ complexes occurred in three stages corresponding to the release of 4, 1 and 1 NH₃ equivalents respectively. The chloride and bromide both exhibit a deammoniation onset temperature below 323 K. The di-ammoniates from the first desorption step were isolated during TPD measurements and their crystal structures determined by Rietveld refinement against PXRD data (X = Cl: orthorhombicCmmm, a = 8.1991(9) Å, b = 8.2498(7) Å, c = 3.8212(4) Å, Z = 2; X = Br: orthorhombic Pbam, a = 6.0109(5) Å, b = 12.022(1) Å, c = 4.0230(2) Å, Z= 2).

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Reardon, Miss Hazel and Hanlon, Dr James and Fullbrook, Miss Imogen and Gregory, Professor Duncan
• Authors: Reardon, H., Hanlon, J. M., Grant, M., Fullbrook, I., and Gregory, D. H.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Crystals
• Publisher: MDPI
• ISSN: 2073-4352
• ISSN (Online): 2073-4352
• Copyright Holders: Copyright © 2012 The Authors
• First Published: First published in Crystals 2(4):193-212
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
44653	1	SUPERGEN programme renewal	Duncan Gregory	Engineering & Physical Sciences Research Council (EPSRC)	EP/E040071/1	CHEM - CHEMISTRY
55770	1	Crossing Boundaries in Energy Storage	Duncan Gregory	Engineering & Physical Sciences Research Council (EPSRC)	EP/I022570/1	CHEM - CHEMISTRY