Amber L. Thompson

Mar 162011
 

As part of Age Concern, an EPSRC-funded exploration into the world of modern crystallography, Dave is developing a fast, live, configurable chemical structure matching algorithm to identify discrepancies between an expected structure and a real crystallographic structure. Implemented in his software “matchbOx”, Dave is augmenting the software capabilities to automatically handle certain cases of crystal disorder, whilst enjoying the best music the 80s has to offer. When not advancing the boundaries of science, Dave enjoys weight-training, making music and working on pet programming projects.

Mar 162011
 

Mr. Keith R. J. WatersKeith is our part time X-ray technician.  He has responsibility for initial Health and Safety training as well as basic instrument and infrastructure maintenance.  In his spare time he works in the IT Support team.

Feb 152011
 

CrystEngComm (2011), 13(8) 2923-2929.    [ doi:10.1039/c0ce00709a ]

A series of racemic or stereochemically labile chiral borate anions based on the 2,20-biphenol motif was
investigated. All borates were homochiral in the solid state, although in some cases the heterochiral
diastereomers were computed to be thermodynamically preferred (DFT). The crystallographic
preference for the homochiral diastereomer was attributed to its lower bulk, higher molecular
symmetry, and the therewith associated better packing ability.

Feb 012011
 

Presented by:  Dr. Andrew D. Schwarz & Liban M. A. Saleh
Research Leader:  Prof. Philip Mountford & Prof. Simon Aldridge
Published:  Journal of the American Chemical Society

Transition-metal boryl compounds (L)M(BX2)x, containing 2‑center, 2‑electron σ‑bonds have been a topic of outstanding interest due to pivotal roles in a variety of catalytic and stoichiometric transformations, e.g. hydroboration and diboration of C–C π-bonds, and functionalization of alkane and arene C‑H bonds. To date, virtually all boryl complexes have been prepared either by B‑X (X = H or halogen) or B‑B oxidative addition to a low oxidation state (L)M species, or by nucleophilic attack of a [(L)M]‑ anion on a XBR2 or related source of the boryl moiety. However, utilisation of the nucleophilic Li{B(NArCH)2}(THF)2 (Ar = 2,6‑C6H3iPr2), allows access to rare earth metal boryl compounds.  Data were collected on a small colourless crystal (0.05 × 0.05 × 0.05 mm) using the new Oxford Diffraction (Agilent) SuperNova diffractometers and copper radiation.

Structure of the Month - February 2011

Structure of the Month – February 2011


Jan 012011
 

Presented by:  Nicholas H. Evans & Christopher J. Serpell
Research Leader:  Prof. Paul D. Beer
Published: Angewandte Chemie International Edition

Catenanes and rotaxanes are highly attractive targets for the supramolecular chemist due to their potential uses as molecular machines or as selective hosts for ionic and molecular guests. This molecule was synthesised via chloride anion templation and crystals grown by slow diffusion of diisopropyl ether into a chloroform/catenane solution.  Data were collected on I19 at Diamond.  This first handcuff catenane structure provided proof of the topology, also revealing potential further uses: the degree of slack in the large macrocycle could allow controlled rotation within the handcuff, and the large number of oxygen atoms in the cavity formed by the handcuff linker and large macrocycle could be used to bind cations.

Structure of the Month - January 2011

Structure of the Month - January 2011

Dec 012010
 

Presented by:  Dr. Adrian B. Chaplin
Research Leader:  Prof. Andrew S. Weller
Published:  Journal of the American Chemical Society

Making and breaking C–C bonds in the solid state:  The structure of [Ir(BINOR‑S)(PiPr3)][BArF4] over the temperature range 100–250 K reveals a dynamic equilibrium between Ir(III) C–C agostic and Ir(V) bis-alkyl tautomers in the solid-state.  The solid-state dynamic behaviour is shown in the reaction scheme (a), with populations determined using X-ray diffraction (b) and the Van’t Hoff plot for this process (c, R2(fit) = 0.999).The disordered model at 150 K containing (d) Ir(III) and (e) Ir(V). The combined model and thermal ellipsoid plot of the structure refined without cation disorder modelling are also shown (f & g respectively).

Structure of the Month - December 2010

Structure of the Month – December 2010

 

Nov 012010
 

Presented by:  Nicola K. S. Davis & Dr. Amber L. Thompson
Research Leader:  Prof. Harry L. Anderson
Published:  Journal of the American Chemical Society

Molecules with large planar π-systems show a strong tendancy to aggregate due to π-π interactions. This tetra-anthracene-fused porphyrin forms dimers with the molecules twisted with respect to each other. Bulky aryl groups were necessary for characterisation, but prevent the porphyrins from forming longer stacks in the crystal.  Using long alkyl chains instead could yield systems which form longer π-stacked arrays which may form discotic liquid crystals.  Furthermore, as the porphyrins stack with a near-zero horizontal offset, these have potential as light harvesting arrays since the alignment of the chromophores provides an efficient pathway for holes and electrons along the column.

Structure of the Month - November 2010

Structure of the Month – November 2010

Sep 012010
 

Presented by:  Dr. Nathan L. Kilah, Matthew D. Wise, Christopher J. Serpell, Nicholas G. White, Dr. Kirsten E. Christensen & Dr. Amber L. Thompson
Research Leader:  Prof. Paul D. Beer
Published:  Journal of the American Chemical Society

This structure represents the first use of solution phase halogen bonding to control and facilitate the anion templated assembly of an interlocked structure.  It  unambiguously confirms the interlocked nature of the system, and the vital role played by halogen bonded anion templation in its assembly.  The crystals were small and diffracted poorly, so data were collected on I19 at Diamond.  Unfortunately, they also suffered severe radiation damage, so data were collected using a single φ scan leading to a paucity of data.  Extensive disorder meant that the final refinement had a data:parameter ratio of 3.6:1 and required 4401 restraints.

Structure of the Month - September 2010

Structure of the Month – September 2010