Author Archive

Perspective: Multi-functional magnets with Prussian blue analogs

04 Apr 2011

In this Dalton Transactions Perspective, Shin-ichi Ohkoshi and Hiroko Tokoro discuss cyano-bridged bimetal assemblies (particularly Prussian blue analogs) that demonstrate novel magnetic functionalities.  Charge-transfer phase transitions, reversible photomagnetism, second harmonic generation along with magnetization-induced second harmonic generation, ferroelectric ferromagnetism, humidity-sensitive magnetism, high ionic conductivity, and a coupling effect (termed spin-ionics) between ionic conduction and magnetic ordering within Prussian blue analogs is described.

Prussian blue analogs have been intensively studied due to (i) their flexible structure, which meet conditions for charge-transfer, photoinduced change, and absorption and desorption of water, and (ii) the strong exchange coupling of the magnetic centers through cyano-bridged ligands.

To find out more about this fascinating area, read for free until 29th April here.

Novel magnetic functionalities of Prussian blue analogs
Hiroko Tokoro and Shin-ichi Ohkoshi
Dalton Trans., 2011, Advance Article, DOI: 10.1039/C0DT01829E

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Hot Article: Precursors for supraicosahedral species

12 Mar 2011

In this new Dalton Transactions Hot Article, Macgregor, Welch, Zanello et al. report the synthesis of carboranes substituted with a range of ArF substituents.  The team also describe the results of spectroscopic, computational and (spectro)electrochemical studies for identifying the best ArF substituent to stabilise the new carboranes once reduced.

Supraicosahedral heteroborane chemistry is an area of contemporary interest. Heteroborane clusters with >12 vertices can be challenging to synthesise and can present interesting problems for computational chemists.

Supraicosahedral heteroborane chemistry is important as  such compounds could find valuable applications in a wide range of fields  from bond activation and homogeneous catalysis to medicine.

Read for free until the 1st April 2011 here.

Spectroscopic, structural, computational and (spectro)electrochemical studies of icosahedral carboranes bearing fluorinated aryl groups
Hugo Tricas, Marta Colon, David Ellis, Stuart A. Macgregor, David McKay, Georgina M. Rosair, Alan J. Welch, Ivan V. Glukhov, Fulvio Rossi, Franco Laschi and Piero Zanello
Dalton Trans., 2011, Advance Article, DOI: 10.1039/C0DT01798A

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Hot Article: Locating H-atoms in MOFs

09 Mar 2011

In this new Dalton Transactions Hot Article, Cheetham et al. use neutron powder diffraction to examine the crystal and magnetic structure of some transition metal gallates.  The team accurately determined the locations of the hydrogen atoms to gain an insight into  how the different valences are accommodated as well as getting details about their magnetic structures.

MOFs have been the focus of extensive research due to their wide variety of intriguing structures and properties.  Most of the effort has focused on their gas adsorption and catalytic capabilities.  Dense frameworks, with extended inorganic connectivity (e.g. metal–oxygen–metal), have also recieved attention recently. These materials can exhibit properties (electrical conductivity and ferromagnetism)that are associated with purely inorganic compounds, such as metal oxides.

Read more about this work for free until 29th March 2011 here.

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
Paul J. Saines, Hamish H.-M. Yeung, James R. Hester, Alistair R. Lennie and Anthony K. Cheetham
Dalton Trans., 2011, Advance Article, DOI: 10.1039/C0DT01687J

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Hot Article: Quaternary pyrochlore oxides – order from chaos?

23 Feb 2011

In this Dalton Transactions Hot Article, which is part of an upcoming themed issue on “Contributions of Inorganic Chemistry to Energy Research” Rao et al. studied the effect of simultaneous substitutions of Ca and Nb or Ta in pyrochlore-type solid solutions using XRD, FT NIR Raman spectroscopic techniques and transmission electron microscopy.  The substitutions lead to a more ordered phase being produced.

Recently, pyrochlore oxides have attracted a lot of attention.  Their chemical and structural flexibility lead to a wide range of properites such as:

  • superconductivity
  • semi-conductivity
  • ionic conductivity
  • ferromagnetism
  • luminescence

Oxide ion-conducting pyrochlores have found applications in solid oxide fuel cells as electrolytes and gas sensors. Within the last decade, the use of pyrochlore oxides for nuclear waste disposal has gained interest due to their high radiation resistance.

Read for free until 22nd March 2011 to find out more about these fascinating and versatile materials here.

Influence of disorder-to-order transition on lattice thermal expansion and oxide ion conductivity in (CaxGd1-x)2(Zr1-xMx)2O7 pyrochlore solid solutions
A. N. Radhakrishnan, P. Prabhakar Rao,* K. S. Mary Linsa, M. Deepa and Peter Koshy
Dalton Trans., 2011, Advance Article, 10.1039/c0dt01688h

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Hot Article: Magnetic horseshoes

15 Feb 2011

In this Dalton Transactions Hot Article, Richard Winpenny and colleagues report the characterisation of isolated finite chromium based horseshoe shaped chains.  The team used INS, magnetic and EPR techniques to determine the inter-chromium exchange coupling and single ion zero field splitting (ZFS) within the chain segments.

Manipulating quantum spin levels via ligands, which play no role in super-exchange, is of general interest to the practise of spin Hamilton modelling.

Interested?  Read more about these magnetic chains here.

Varying spin state composition by the choice of capping ligand in a family of molecular chains: detailed analysis of magnetic properties of chromium(III) horseshoes
Michael L. Baker, Richard E. P. Winpenny et al.
Dalton Trans., 2011, Advance Article, 10.1039/c0dt01243b

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