Unexpected Behaviour in Derivatives of Barluenga's Reagent

Aug 302018
 

Chemical Communications 2018, 54, 9849 – 9852 [doi:10.1039/C8CC05430D]

For the collidine analogues of Barluenga’s Reagent (IPy2BF4) reported, a flat cation is necessary for the generation of a modulated phase, in keeping with the “Ratchet Model” theory [Kim et al., Crystal Growth & Design, 2014, 14, 6294]. Attempts to study “diffuse modulation” in Br(Coll)2ClO4 have shown that these non-Bragg features disappear very rapidly on exposure to synchrotron radiation, an effect thought to be caused by the radiation damage disrupting the lattice vibrations that cause the modulation.

 

Radiation Damage

Prizes at the BCA Spring Meeting

Apr 052018
 

Kiaora Tolmie recieving the CCG Poster PrizeThe 2018 Meeting of the British Crystallographic Association was held at Warwick University where Chem. Cryst. was well represented.  The meeting started with the Young Crystallographers Satellite meeting, during which Lewis Morgan’s oral presentation was so “eggsellent” that he won the Industrial Group Prize for the best talk, and with it, the dubious honour of presenting it again as a plenary in the main meeting.

At the conference dinner Kiaora Tolmie received a CCG CrystEngComm poster prize for her poster on hard-to-crystallize materials, and James Bird was awarded the YCG I’m-a-scientist-get-me-out-of here prize for the poster presenter who most clearly and enthusiastically communicated their results.

Congratulations to all three winners!

 

Lewis Morgan delivering his prize-winning presentation at the BCA Spring Meeting 2018

Lewis Morgan delivering his prize-winning presentation

 

A full list of the presentations from Chem. Cryst.:

George A. Sackman & Richard I. Cooper
Distinguishing Disorder: A Molecular Dynamics Approach (Poster Presentation)

Kiaora L. M. Tolmie & Richard I. Cooper
Structure Determination of Hard-to-Crystallize Materials (Poster Presentation)

Lewis C. F. Morgan, Jack N. Blandy, Claire A. Murray, Kirsten E. Christensen & Amber L. Thompson
Improving Our Understanding of Modulation in Molecular Materials (Poster & Oral Presentation)

James M. Bird & Richard I. Cooper
A Comparison of Molecular Dynamics Techniques for Simulation of Thermal Disorder in Molecular Crystals (Poster Presentation)

Oliver J. A. Bar & Richard I. Cooper
A Study of Phase Transitions in Organic and Metal-organic Inclusion Complexes through Molecular Dynamics Simulation (Poster Presentation)

Richard I. Cooper
CrysPy: CRYSTALS in Python (Poster Presentation)

Amber L. Thompson
When are Bad Data Good Data? (Keynote Oral Presentation)

Toward the Understanding of Modulation in Molecular Materials: Barluenga's Reagent and its Analogues

Oct 302014
 

Crystal Growth & Design (2014). 14 (12), 6294–6301. [ doi:10.1021/cg500983s ]

ratchetInvestigations into the phase transition of Barluenga’s reagent revealed a transient incommensurately modulated phase. To understand the origin of the modulated phase and the chemistry that can affect it, analogues of Barluenga’s reagent were synthesized and studied. In this context, the halogen and anion can easily be exchanged. Studying different analogues led to the development of the Ratchet Model to describe the behavior in the solid state leading to a better understanding of modulation in this class of molecular crystal structure.

Publisher’s copy

 

Dr. Kirsten E. Christensen

Oct 072011
 

Photo of Kirsten ChristensenKirsten’s research is focused on several areas that will establish a fundamental understanding of modulation in molecular materials e.g. their formation and properties. This knowledge can be put to immediate use in Crystal Engineering, and will also affect research in pharmaceuticals, developments in molecular modelling and crystal packing predictions.

See Kirsten’s Departmental web-page for further information.