<i>SIR</i>97: a new tool for crystal structure determination and refinement

Altomare, Angela; Burla, Maria Cristina; Camalli, Mercedes; Cascarano, G.; Giacovazzo, Carmelo; Guagliardi, Antonietta; Moliterni, Anna; Polidori, Giampiero; Spagna, R.

doi:10.1107/s0021889898007717

Cited by 9,696 publications

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References 16 publications

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“…www.chemeurj.org Crystal structure determinations: X-ray intensities were measured on a Nonius KappaCCD diffractometer with rotating anode and graphite monochromator (l = 0.71073 ). The structures were solved with automated Patterson Methods [34] (compounds 7, 12 a, 14, 16 b, 21 a, and 28 a) or Direct Methods [35] (compound 17 a) and refined with SHELXL-97 [36] on F 2 of all reflections. Geometry calculations, drawings and checking for higher symmetry were performed with the PLATON [37] package.…”

Section: Resultsmentioning

confidence: 99%

Linear and Branched Phospha[n]triangulanes

Slootweg

Kanter

Schakel

et al. 2005

Chemistry A European J

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Chip als Spürnase: Empfindlicher denn je lassen sich Explosivstoffe mit Siliciumnanodraht‐Feldeffekttransistor‐Sensoranordnungen nachweisen, die mit Monoschichten eines elektronenreichen Aminosilans modifiziert sind und Komplexe mit den Analyten bilden (siehe Bild). Diese Nano‐„Spürnasen“ bemerken TNT‐Konzentrationen von nur 1×10−6 ppt und sind somit Spürhunden und allen anderen bekannten Nachweismethoden für Explosivstoffe überlegen.

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Section: Resultsmentioning

confidence: 99%

Linear and Branched Phospha[n]triangulanes

Slootweg

Kanter

Schakel

et al. 2005

Chemistry A European J

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“…X-ray crystallography: X-ray intensities for complexes 2-4 were collected by using a Nonius-Kappa CCD diffractometer with rotating anode. The structures were solved by using direct methods (compound 2 with SHELXS-97, [50] compound 4 with SIR-97) [51] or automated Patterson methods (compound 3, DIRDIF-99), [52] and refined with SHELXL-97 [53] against F 2 of all reflections. Non-hydrogen atoms were refined freely with anisotropic displacement parameters.…”

Section: Methodsmentioning

confidence: 99%

Unique Ligand‐Based Oxidative DNA Cleavage by Zinc(II) Complexes of Hpyramol and Hpyrimol

Maheswari

Barends

Özalp-Yaman

et al. 2007

Chemistry A European J

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The zinc(II) complexes reported here have been synthesised from the ligand 4‐methyl‐2‐N‐(2‐pyridylmethyl)aminophenol (Hpyramol) with chloride or acetate counterions. All the five complexes have been structurally characterised, and the crystal structures reveal that the ligand Hpyramol gradually undergoes an oxidative dehydrogenation to form the ligand 4‐methyl‐2‐N‐(2‐pyridylmethylene)aminophenol (Hpyrimol), upon coordination to ZnII. All the five complexes cleave the ϕX174 phage DNA oxidatively and the complexes with fully dehydrogenated pyrimol ligands were found to be more efficient than the complexes with non‐dehydrogenated Hpyramol ligands. The DNA cleavage is suggested to be ligand‐based, whereas the pure ligands alone do not cleave DNA. The DNA cleavage is strongly suggested to be oxidative, possibly due to the involvement of a non‐diffusible phenoxyl radical mechanism. The enzymatic religation experiments and DNA cleavage in the presence of different radical scavengers further support the oxidative DNA cleavage by the zinc(II) complexes.

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“…The structure was solved by direct methods (SIR97). 70 All calculations were performed with the XTAL system. 71 Full-matrix least-squares refinement based on F using weights of 1/(σ 2 (Fo) + 0.00015(Fo 2 )) gave final values R ) ωR ) 0.037, and S ) 1.84(4) for 176 variables and 1516 contributing reflections.…”

Section: Methodsmentioning

confidence: 99%

Self-Sorting Chiral Subcomponent Rearrangement During Crystallization

et al. 2007

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Abstract:The incorporation of enantiopure 1-amino-2,3-propanediol as a subcomponent into a dicopper double helicate resulted in perfect chiral induction of the helicate's twist. DFT calculations allowed the determination of the helicity of the complex in solution. The same helical induction, in which S amines induced a Λ helical twist, was observed in the solid state by X-ray crystallography. Electronic structure calculations also revealed that the unusual deep green color of this class of complexes was due to a metalto-ligand charge transfer excitation, in which the excited state possesses a valence delocalized Cu2 3+ core. The use of a racemic amine subcomponent resulted in the formation of a dynamic library of six diastereomeric pairs of enantiomers. Surprisingly, this library converted into a single pair of enantiomers during crystallization. We were able to observe this process reverse upon redissolution, as initial ligand exchange was followed by covalent imine metathesis.

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SIR97: a new tool for crystal structure determination and refinement

Cited by 9,696 publications

References 16 publications

Linear and Branched Phospha[n]triangulanes

Linear and Branched Phospha[n]triangulanes

Unique Ligand‐Based Oxidative DNA Cleavage by Zinc(II) Complexes of Hpyramol and Hpyrimol

Self-Sorting Chiral Subcomponent Rearrangement During Crystallization

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