Thank you Tim, I had the same impression. I am afraid that our chemists will have to wait a little longer before they routinely can get absolute configurations from electron diffraction.
Best Herman -----Ursprüngliche Nachricht----- Von: Tim Gruene <tim.gru...@univie.ac.at> Gesendet: Montag, 20. Juli 2020 14:21 An: Schreuder, Herman /DE <herman.schreu...@sanofi.com> Cc: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> Betreff: Re: [EXTERNAL] chirality with electron diffraction EXTERNAL : Real sender is tim.gru...@univie.ac.at Dear Herman, no, I don't think this is routine, yet! First of all, instrument manufacturers need to catch up. What's on the market is quite behind what is possible - although, I don't have the instrument I'd love to have, but at least the meta data transfer to the image headers only works when you work with a native CCD camera (stone age, I know), not with a hybrid pixel detector. Secondly, Lukas Palatinus' software is, as far as I know, not yet compatible with the rotation method, i.e. when you use XDS or DIALS or mosflm, etc, you cannot use his software for dynamic refinement. I also understand that dynamic refinement is quite time consuming. Lukas is working on this, though. Best wishes, Tim On Mon, 20 Jul 2020 10:36:49 +0000 "Schreuder, Herman /DE" <herman.schreu...@sanofi.com> wrote: > Hi Tim, > > thank you for your reply. The 1998 Schenk paper is "new" to me, I had > seen this one: > https://science.sciencemag.org/content/sci/364/6441/667.full.pdf The > background of my question was about the status in practice: Is it > possible to routinely determine the absolute configuration of small > molecules by electron diffraction, or is it something that in theory > can be done, but only difficult in practice? > > Best, > Herman > > > > -----Ursprüngliche Nachricht----- > Von: Tim Gruene <tim.gru...@univie.ac.at> > Gesendet: Montag, 20. Juli 2020 11:03 > An: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK>; Schreuder, Herman /DE > <herman.schreu...@sanofi.com> Betreff: [EXTERNAL] chirality with > electron diffraction > > EXTERNAL : Real sender is tim.gru...@univie.ac.at > > > > Dear Herman, > > The absolute configuration can be determined, although very > differently from X-ray ccrystallography. > > So far, two different experimental approaches have been published: > Ma, Oleynikov, Terasaki (2017), https://doi.org/10.1038/nmat4890 > > and Brazda et al (2019), 10.1126/science.aaw2560 > > The former is based on imaging, the latter is based on dynamical > refinement: Jansen, Tang, Zandbergen, Schenk (1998), > https://doi.org/10.1107/S0108767397010489 > > There is a very interesting paper by Burmester and Schroeder Scanning > Microscopy Vol. 11, 1997 (Pages 323-334). According to this paper, the > anomalous signal in ED is actually stronger than in X-ray > crystallography. As far as I know, this has not been pursued further. > > Best wishes, > Tim > > P.S.: This is a response to your email to Jessica Bruhns in the thread > 'quote source inquiry'. This thread has reached an overflow, so I took > the liberty to adjust the subject. > > -- > -- > Tim Gruene > Head of the Centre for X-ray Structure Analysis Faculty of Chemistry > University of Vienna > > Phone: +43-1-4277-70202 > > GPG Key ID = A46BEE1A -- -- Tim Gruene Head of the Centre for X-ray Structure Analysis Faculty of Chemistry University of Vienna Phone: +43-1-4277-70202 GPG Key ID = A46BEE1A ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
