Journal ArticleDOI
Phase annealing in SHELX-90: direct methods for larger structures
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TLDR
In this article, a phase annealing method, related to the simulated-annealing approach in other optimization problems, is proposed and it is shown that it can result in an improvement of up to an order of magnitude in the chances of solving large structures at atomic resolution.Abstract:
A number of extensions to the multisolution approach to the crystallographic phase problem are discussed in which the negative quartet relations play an important role. A phase annealing method, related to the simulated annealing approach in other optimization problems, is proposed and it is shown that it can result in an improvement of up to an order of magnitude in the chances of solving large structures at atomic resolution. The ideas presented here are incorporated in the program system SHELX-90; the philosophical and mathematical background to the direct-methods part (SHELXS) of this system is described.read more
Citations
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Journal ArticleDOI
Arylethynyl derivatives of the dihydroazulene/vinylheptafulvene photo/thermoswitch: tuning the switching event.
Søren Lindbæk Broman,Michael Åxman Petersen,Christian Tortzen,Anders Kadziola,Kristine Kilså,Mogens Brøndsted Nielsen +5 more
TL;DR: An interesting byproduct in a Sonogashira cross-coupling reaction involving a nitrophenyl group was discovered, namely a diaryl azoxy compound, which was confirmed by X-ray crystallographic analysis.
Journal ArticleDOI
Metal-Organic Architectures Assembled from Multifunctional Polycarboxylates: Hydrothermal Self-Assembly, Structures, and Catalytic Activity in Alkane Oxidation.
Jin-Zhong Gu,Min Wen,Yan Cai,Zi-Fa Shi,A. S. Arol,Marina V. Kirillova,Alexander M. Kirillov,Alexander M. Kirillov +7 more
TL;DR: These copper(II) derivatives efficiently catalyze the oxidation of cycloalkanes with hydrogen peroxide under mild conditions and opening up their use as multicarboxylate ligands toward the design of copper-organic architectures.
Journal ArticleDOI
New hypervalent iodine reagents for electrophilic trifluoromethylation and their precursors: synthesis, structure, and reactivity
Katrin Niedermann,Jan M. Welch,Raffael Koller,Ján Cvengroš,Nico Santschi,Philip Battaglia,Antonio Togni +6 more
TL;DR: Several new five and a six-membered heterocyclic monochloroiodanes, including two cationic species, were synthesized in this paper, three of which were used for the preparation of corresponding trifluoromethylation reagents.
Journal ArticleDOI
Unsymmetrically Substituted 9,10-Dihydro-9,10-diboraanthracenes as Versatile Building Blocks for Boron-Doped π-Conjugated Systems
Estera Januszewski,Andreas Lorbach,Rekha Grewal,Michael Bolte,Jan W. Bats,Hans-Wolfram Lerner,Matthias Wagner +6 more
TL;DR: The targeted hydrolysis of the 9,10-dihydro-9, 10-diboraanthracene adduct with 0.5 equiv of H(2)O leads to formation of the borinic acid anhydride, which provides access to the field of unsymmetrically substituted 9,000-diluted diboraAnthracenes.
Journal ArticleDOI
Hybrid open-framework iron phosphate--oxalates demonstrating a dual role of the oxalate unit
TL;DR: The formation of two types of inorganic layers in I and II consisting of four-, six-, and eight-membered rings, indicates the interconversions between the various rings in the phosphate--oxalates to be facile.
References
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Book
Crystallographic Computing 3: Data Collection, Structure Determination, Proteins and Databases
TL;DR: The latest in a series on crystallographic computing, this collection of 33 papers covers the full spectrum of computer applications in crystallography, including the use of micro-, mini-, and mainframe computers.