Detailed investigations of phase transitions and magnetic structure in Fe(iii), Mn(ii), Co(ii) and Ni(ii) 3,4,5-trihydroxybenzoate (gallate) dihydrates by neutron and X-ray diffraction

Saines, P.J. and Yeung, H.H.-M. and Hester, J.R. and Lennie, A.R. and Cheetham, A.K. (2011) Detailed investigations of phase transitions and magnetic structure in Fe(iii), Mn(ii), Co(ii) and Ni(ii) 3,4,5-trihydroxybenzoate (gallate) dihydrates by neutron and X-ray diffraction. Dalton Transactions, 40 (24). pp. 6401-6410. ISSN 14779226 (ISSN). (doi:https://doi.org/10.1039/c0dt01687j) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://www.scopus.com/inward/record.url?eid=2-s2.0...

Abstract

The effect of cation valency on the complex structures of divalent and trivalent transition metal gallates has been examined using a combination of neutron and synchrotron X-ray powder diffraction, single-crystal X-ray diffraction and XANES spectroscopy. In the divalent frameworks, M(C 7H4O5)·2H2O (M = Mn, Co and Ni), it was found that charge balance was achieved via the presence of protons on the meta-hydroxyl groups. It was also established that these compounds undergo a discontinuous phase transition at lower temperatures, which is driven by the position of the extra-framework water molecules in these materials. By contrast, in the trivalent Fe gallate, Fe(C7H3O 5)·2H2O, it was found that the stronger bonding between the meta-hydroxy oxygen and the cations leads to a weakening of the bond between this oxygen and its proton. This is turn is thought to lead to stronger hydrogen bonding with the extra-framework water. The lattice water is disordered in the Fe(iii) case, which prevents the phase transition found in the M(ii) gallates. Refinement against the neutron diffraction patterns also revealed that the relatively mild microwave synthesis of gallate frameworks in D2O led to an extensive deuteration of the ortho-hydrogen sites on the aromatic ring, which may suggest a more versatile method of deuterating aromatic organics. The antiferromagnetic structure of Co gallate has also been determined. © 2011 The Royal Society of Chemistry.

Item Type: Article
Additional information: Unmapped bibliographic data: LA - English [Field not mapped to EPrints] J2 - Dalton Trans. [Field not mapped to EPrints] AD - Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ, United Kingdom [Field not mapped to EPrints] AD - Bragg Institute, ANSTO, Locked Bag 2001, Kirrawee DC NSW 2232, Australia [Field not mapped to EPrints] AD - Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints]
Uncontrolled keywords: Antiferromagnetic structures, Aromatic rings, Cation valency, Charge balances, Complex structure, Deuterations, Dihydrates, Gallate, Lattice water, Microwave synthesis, Organics, Single crystal x-ray diffraction, Synchrotron X ray powder diffraction, Trivalent transition, Versatile methods, Water molecule, Antiferromagnetic materials, Antiferromagnetism, Aromatic compounds, Cobalt, Cobalt compounds, Crystal structure, Crystallography, Deuterium, Hydrogen, Hydrogen bonds, Iron compounds, Manganese, Manganese compounds, Neutrons, Oxygen, Phase transitions, Positive ions, Protons, X ray absorption near edge structure spectroscopy, X ray diffraction, X ray powder diffraction, Diffraction
Subjects: Q Science > QC Physics > QC173.45 Condensed Matter
Q Science > QD Chemistry > QD478 Solid State Chemistry
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Paul Saines
Date Deposited: 07 Oct 2015 10:07 UTC
Last Modified: 07 Oct 2015 10:08 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50729 (The current URI for this page, for reference purposes)
  • Depositors only (login required):