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
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Countercomplementarity and strong ferromagnetic coupling in a linear mixed mu-acetato, mu-hydroxo trinuclear copper(II) complex. Synthesis, structure, magnetic properties, EPR, and theoretical studies.
Laura Gutierrez,Gloria Alzuet,José Antonio Real,Joan Cano,Joaquín Borrás,Alfonso Castiñeiras +5 more
TL;DR: The ferromagnetic exchange coupling is discussed using DFT calculations on model compounds that have shown a countercomplementary effect of the hydroxo and acetate bridges.
Journal ArticleDOI
Three‐Dimensional Organically Templated Open‐Framework Transition Metal Selenites
TL;DR: One dimensional channels are formed in the three-dimensional open-framework iron selenite (I), which was synthesized hydrothermally from FeCl 3 ·6H 2 O, HF, and SeO 2 in the presence of the organic amine piperazine.
Journal ArticleDOI
An Inorganic Helix [Mn(IPG)(MeOH)]n[PF6]n[‡]: Structural and Magnetic Properties of a syn-anti Carboxylate-Bridged Manganese(II) Chain Involving a Tetradentate Ligand
TL;DR: In this article, the crystal structure of an infinite inorganic chain consisting of MnII and an N-centered tripodal ligand N,N-(2-pyridylmethyl)[(1-methylimidazol-2-yl)-methyl] is presented.
Journal ArticleDOI
One-electron reduction of kinetically stabilized dipnictenes: synthesis of dipnictene anion radicals.
Takahiro Sasamori,Eiko Mieda,Noriyoshi Nagahora,Kazunobu Sato,Daisuke Shiomi,Takeji Takui,Yoshinobu Hosoi,Yukio Furukawa,Nozomi Takagi,Shigeru Nagase,Norihiro Tokitoh +10 more
TL;DR: The redox behavior of kinetically stabilized dipnictenes, BbtE=EBbt, showed reversible one-electron redox couples in the reduction region, and their structures were reasonably characterized by ESR, UV-vis, and Raman spectroscopy.
Journal ArticleDOI
Silica-supported imine palladacycles - recyclable catalysts for the Suzuki reaction?
Robin B. Bedford,Catherine S. J. Cazin,Michael B. Hursthouse,Mark E. Light,Kevin J Pike,Stephen Wimperis +5 more
TL;DR: In this article, the crystal structure of complex 9, the triphenylphosphine adduct of the pre-supported precursor complex 8, has been determined and the solid-supported catalysts show considerably lower activity in the Suzuki reaction than their homogeneous counterparts.
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.