MOFs – Chemical Crystallography

Structure of the Month – November 2012

Nov 012012

Presented by: Vanessa E. Fairbank & Dr. Amber L. Thompson
Research Leader: Dr. Andrew L. Goodwin
Published: Physical Review B

Cubic Cd(CN)₂ shows the strongest known isotropic negative thermal expansion (NTE; volume contraction on heating). Variable-temperature single-crystal X‑ray diffraction suggests there is temperature-dependent off-centering of Cd²⁺ ions that has the effect of increasing the cadmium coordination volume at low temperatures, providing an alternate mechanism for NTE in this material. These displacements are evident in the residual electron density and the highly-structured diffuse scattering in the experimental X-ray diffraction patterns. Using Monte Carlo simulations, we have interpreted these patterns in terms of a basic set of “ice-rules” that establish a mapping between the dynamics of Cd(CN)₂and proton ordering in cubic ice VII.

Structure of the Month – November 2012

Mr. Conor P. Rowley

Oct 102012

Conor is spending most of his Part II year in Australia with the Cameron Kepert’s Research Group at the University of Sydney. He is working on the in situ analysis of CO₂ adsorption in metal-organic frameworks. This involves a specially designed setup allowing the use of single crystal X-ray diffraction to ascertain structural information on CO₂ binding in these frameworks. When not in the lab, Conor can be found learning to surf on Bondi Beach.

BCA Spring Meeting 2012

Apr 202012

The 2012 Meeting of the British Crystallographic Association was held at Warwick University. Oxford was very well represented this year with Kirsten Christensen chairing the Programme Committee and prizes being awarded to Joe Paddison, Nick Funnell and Emma McKinley.

Other contributions from Oxford include:

Karim J. Sutton, Kirsten E. Christensen, Amber L. Thompson & Richard I. Cooper
Exploiting the Tunable Wavelength Capabilities of I19 (Poster & Oral Presentation)

Callum A. Young & Andrew L. Goodwin
An Examination of the Low Temperature Structure of Fe₃O₄ Using Reverse Monte Carlo Refinements (Oral Presentation)

Andrew L. Goodwin
Frameworks, Flexibility and Frustration (Oral Presentation)

Kirsten E. Christensen, Amber L. Thompson & Arwen R Pearson
Discussion Forum: From Small Molecules to Proteins: Bridging the Gap

Emma J. McKinley, Kirsten E. Christensen & Amber L. Thompson
Investigation of the Transient Modulated Phase of Barluenga’s Reagent (Poster)

Andrew B. Cairns, Amber L. Thompson, Andrew L, Goodwin, Matthew G. Tucker & Julien Haines
Anomalous Compression of Cyanide Frameworks: Mechanisms for Extreme Negative Response (Poster)

Callum A. Young, Edward Dixon, Michael A. Hayward & Andrew L. Goodwin
Apical Oxygen Bonding in YBCO – A Reverse Monte Carlo Approach (Poster)

Ines E. Collings, Andrew B. Cairns, Amber L. Thompson, Andrew L, Goodwin, Philip Pattison, Julien Haines, Matthew G. Tucker, Julia E. Parker & Chiu C. Tang
Transferable Mechanics in Molecular Framework Materials (Poster)

Joseph A. M. Paddison, Andrew L. Goodwin, Ross Stewart, Pascal Manuel, Matthias J. Gutmann, David A. Keen, Matthew G. Tucker, Andrew Wildes & Brian Rainford
Frustration and Magnetic Diffuse Scattering in β-Mn_0.8Co_0.2 and MnO: A Reverse Monte Carlo Study (Poster)

Matthew Cliffe & Andrew L. Goodwin
Disorder and Defects in Zirconium MOFs (Poster)

Nicholas P. Funnell, Martin T. Dove Andrew L. Goodwin Simon Parsons & Matthew G. Tucker
How Molecules Prepare to Undergo a Transition: The Onset of Disorder in Solid Cyclohexane (Poster).

Karim speaks to the Young Crystallographers

Emma, Richard and Ines go to the conference dinner

Ines and Emma

This time Karim brought his Dad…

Callum and Emma at Dinner

Kirsten presents Nick with his prize

Emma receives her prize

Contemplating Fourier Transforms…

Structure of the Month – September 2011

Sep 012011

Presented by: Andrew B. Cairns & Dr. Amber L. Thompson
Research Leader: Dr. Andrew L. Goodwin
Published: Journal of the American Chemical Society (cover article)

Negative Linear Compressibility (NLC) is where a material unusually expands in one direction under increasing pressure. Potassium manganese dicyanoargentate exhibits the largest NLC over an extended range of any known material: ‑12.0(8) TPa^–1. The structural features are both beautiful and unique to cause this effect. [MnN₆] octahedra are connected via almost linear ‘floppy’ NC–Ag–CN units, with K⁺ ions positioned above and below alternating Ag₃ Kagome triangles (top). The lattice framework is made up of three independent interpenetrated a-Polonium nets (bottom right), with only weak argentophilic interactions between the nets. Variable temperature SCXRD was carried out in Oxford and the variable pressure work was the first pressure experiment carried out on WISH at ISIS.

Structure of the Month – September 2011

Mr. Shahzad Sharif

Jul 282011

Sharif is a Research Officer in the Materials Chemistry Laboratory at the GC University, Lahore. He is doing a Ph.D. in Lanthanide Coordination Polymers under the supervision of Prof. Dr Islam Ullah Khan, studying their Magnetic, Luminescent and MOF behaviour. Sharif is visiting Chem. Cryst. for six months under an IRSIP (HEC) scholarship to learn more about Crystallography and Materials Chemistry.