BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:New Experimental Techniques for Exploring Crystallization Pathways
  and Structural Properties of Solids - Kenneth D.M. Harris\, School of Che
 mistry\, Cardiff University
DTSTART:20161212T100000Z
DTEND:20161212T110000Z
UID:TALK69084@talks.cam.ac.uk
CONTACT:Duncan Johnstone
DESCRIPTION:The lecture will highlight three experimental strategies that 
 we have developed for exploring crystallization pathways and structural pr
 operties of solids: (i) in-situ solid-state NMR techniques for understandi
 ng the time-evolution of crystallization processes\, (ii) the study of X-r
 ay birefringence for spatially resolved mapping of the distribution of mol
 ecular orientations in materials\, and (iii) structure determination of or
 ganic materials when single crystals cannot be prepared.\n\nOur in-situ so
 lid-state NMR technique [1-3] for studying crystallization pathways exploi
 ts the ability of NMR to selectively detect the solid phase in heterogeneo
 us solid/liquid systems of the type that exist during crystallization from
  solution. We have shown that this technique can establish the sequence of
  solid phases formed during crystallization processes [1] and can be explo
 ited in the discovery of new polymorphs [2]. Our most recent development i
 s an in-situ NMR technique [3] that yields simultaneous information on the
  time-evolution of both the solid phase and the liquid phase during crysta
 llization. This new strategy (called "CLASSIC NMR" [3]) extends significan
 tly the scope and capability of in-situ NMR for gaining fundamental insigh
 ts on the evolution of crystallization processes.\n\nFollowing our earlier
  studies of the phenomenon of X-ray birefringence [4\,5]\, we recently rep
 orted [6] a new experimental set-up that allows spatially revolved measure
 ments of X-ray birefringence to be carried out in "imaging mode". In many 
 respects\, this technique (called X-ray Birefringence Imaging) represents 
 the X-ray analogue of the polarizing optical microscope. The lecture will 
 describe the first results obtained using this technique\, demonstrating t
 he utility and potential of X-ray Birefringence Imaging as a sensitive tec
 hnique for imaging the local orientational properties of anisotropic mater
 ials [6]. Inter alia\, the technique can be applied to characterize change
 s in molecular orientational ordering associated with solid-state phase tr
 ansitions and to determine the size\, spatial distribution and temperature
  dependence of domain structures in materials.\n\nFinally\, although singl
 e-crystal X-ray diffraction (XRD) is a very powerful technique for determi
 ning crystal structures\, the requirement for a single crystal is a limita
 tion on the scope of this technique. For materials that cannot be grown as
  suitable single crystals\, structure determination must be tackled instea
 d from powder XRD data. However\, structure determination from powder XRD 
 data is much more challenging than from single-crystal XRD data\, particul
 arly in the case of organic materials. Indeed\, as recently as the early 1
 990s\, no organic crystal structure had ever been determined directly from
  powder XRD data. Since that time\, developments in methodology (particula
 rly the direct-space strategy for structure solution [7]) are such that cr
 ystal structures of organic materials of moderate complexity can now be de
 termined relatively routinely from powder XRD data [8-10]. The lecture wil
 l give an overview of the current opportunities for carrying out structure
  determination of organic materials directly from powder XRD data\, with e
 xamples from chemical\, materials\, pharmaceutical and biological sciences
 .\n\n\n[1] C.E. Hughes\, K.D.M. Harris\, J. Phys. Chem. A\, 2008\, 112\, 6
 808.\n[2] C.E. Hughes\, P.A. Williams\, T.R. Peskett\, K.D.M. Harris\, J. 
 Phys. Chem. Lett.\, 2012\, 3\, 3176.\n[3] C.E. Hughes\, P.A. Williams\, K.
 D.M. Harris\, Angew. Chemie Int. Ed.\, 2014\, 53\, 8939.\n[4] B.A. Palmer\
 , A. Morte-Ródenas\, B.M. Kariuki\, K.D.M. Harris\, S.P. Collins\, J. Phy
 s. Chem. Lett.\, 2011\, 2\, 2346.\n[5] B.A. Palmer\, G.R. Edwards-Gau\, A.
  Morte-Ródenas\, B.M. Kariuki\, G.K. Lim\, K.D.M. Harris\, I.P. Dolbnya\,
  S.P. Collins\, J. Phys. Chem. Lett.\, 2012\, 3\, 3216.\n[6] B.A. Palmer\,
  G.R. Edwards-Gau\, B.M. Kariuki\, K.D.M. Harris\, I.P. Dolbnya\, S.P. Col
 lins\, Science\, 2014\, 344\, 1013.\n[7] K.D.M. Harris\, M. Tremayne\, P. 
 Lightfoot\, P.G. Bruce\, J. Am. Chem. Soc.\, 1994\, 116\, 3543.\n[8] K.D.M
 . Harris\, Top. Curr. Chem.\, 2012\, 315\, 133.\n[9] K. Fujii\, M.T. Young
 \, K.D.M. Harris\, J. Struct. Biol.\, 2011\, 174\, 461.\n[10] P.A. William
 s\, C.E. Hughes\, K.D.M. Harris\, Angew. Chemie Int. Ed.\, 2015\, 54\, 397
 3.
LOCATION:Goldsmiths 1\, Lecture room\, Dept. of Materials Science and Meta
 llurgy
END:VEVENT
END:VCALENDAR