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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Pyrazolate-based cobalt(II)-containing metal-organic frameworks in heterogeneous catalytic oxidation reactions: elucidating the role of entatic states for biomimetic oxidation processes.
Markus Tonigold,Ying Lu,Andreas Mavrandonakis,Angela Puls,Reiner Staudt,Jens Möllmer,Joachim Sauer,Dirk Volkmer +7 more
TL;DR: Crystal structures of two metal-organic frameworks (MFU-1 and MFU-2) are presented, both of which contain redox-active Co(II) centres coordinated by linear 1,4-bis[(3,5-dimethyl)pyrazol-4-yl] ligands, which show excellent stability against hydrolytic decomposition.
Journal ArticleDOI
Synthesis, structural characterization, antiradical and antidiabetic activities of copper(II) and zinc(II) Schiff base complexes derived from salicylaldehyde and β-alanine
TL;DR: In this paper, a series of copper(II) and zinc (II) complexes involving a tridentate O,N,O'-donor Schiff base derived from salicylaldehyde and beta-alanine is presented.
Journal ArticleDOI
Porous metal-organic framework with coordinatively unsaturated Mn(II) sites:sorption properties for various gases.
TL;DR: Desolvated solid [Mn(NDC)]n (2), which contains coordinatively unsaturated Mn(II) sites, reveals remarkable sorption capabilities for N2, H2, CO2, and CH4 gases and exhibits type I sorption behavior indicative of permanent microporosity.
Journal ArticleDOI
Controlling copper(I) halide framework formation using N-donor bridging ligand symmetry: use of 1,3,5-triazine to construct architectures with threefold symmetry
Alexander J. Blake,Neil R. Brooks,Neil R. Champness,Paul A. Cooke,Anne M. Deveson,Dieter Fenske,Peter Hubberstey,Wan-Sheung Li,Martin Schröder +8 more
TL;DR: In this paper, the formation of co-ordination polymers between copper(I) halides and 1,3,5-triazine (tri), a potentially tridentate N-donor bridging ligand with threefold symmetry, has been studied.
Journal ArticleDOI
N,N-addition of frustrated Lewis pairs to nitric oxide: an easy entry to a unique family of aminoxyl radicals.
Muhammad Sajid,Annika Stute,Allan Jay P. Cardenas,Brooks J. Culotta,Johannes A. M. Hepperle,Timothy H. Warren,Birgitta Schirmer,Stefan Grimme,Armido Studer,Constantin G. Daniliuc,Roland Fröhlich,Jeffrey L. Petersen,Gerald Kehr,Gerhard Erker +13 more
TL;DR: The FLP-NO systems represent a new family of aminoxyl radicals that are easily available by N,N-cycloaddition of C(2)-bridged intramolecular P/B frustrated Lewis pairs to nitric oxide.
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.