title: Automated chemical crystallography.
abstract: The first fully automated small-molecule robotic X-ray diffractometer is described. After demonstrating the utility of the instrument using multiple samples of ammonium bitartrate, we investigated the conformational chirality of diphenyl dichalcogenide (E(2)Ph(2), where E = S, Se, or Te). Structural and computational studies suggest that the two enantiomers are energetically indistinguishable. Therefore, it was unsurprising that we found (in 35 suitable data collections) the proportion 0.51:0.49 of M-S(2)Ph(2) to P-S(2)Ph(2) in the bulk sample. Interestingly, after 65 data collections of Te(2)Ph(2), (46 provided suitable data sets), we found the proportion 0.72 +/- 0.13 of M-Te(2)Ph(2), suggesting there could be a statistically significant preference for the M-enantiomer in the sample examined here. We found that Se(2)Ph(2) underwent homochiral crystallization, with all 24 crystals being M. Our experiments may represent a salutary lesson in statistical analysis.
authors.affiliation: School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST UK.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Fuller
authors.forename: Lindesay A S
authors.initials: LA
authors.lastname: Scott-Hayward
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Bühl
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.forename: J Derek
authors.initials: JD
authors.lastname: Woollins