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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Synthesis, crystal structures and magnetic properties of 1D polymeric [MnIII(salen)N3] and [MnIII(salen)Ag(CN)2] complexes
TL;DR: In this paper, the syntheses, crystal structures and variable temperature magnetic susceptibility measurements of two salen complexes of manganese(III) have been reported, where azido and dicyano argentate(I) as bridging ligands are reported.
Journal ArticleDOI
Structural analysis and magnetic properties of the 1D and 3D compounds [Mn(dca)2nbipym] (M = Mn, Cu; dca = dicyanamide; bipym = bipyrimidine; n = 1,2).
Susana Martín,M. Gotzone Barandika,J. Ignacio Ruiz de Larramendi,Roberto Cortés,‡ Mercedes Font-Bardia,Luis Lezama,Zurine E. Serna,and Xavier Solans,Teófilo Rojo +8 more
TL;DR: While compound 1 is one-dimensional, with the manganese(II) ions bridged by double mu1,5-dicyanamide ligands, the structural arrangement in compounds 2 and 3 is three-dimensional based on ladder-like moieties.
Journal ArticleDOI
1′,1′′′-Bis(ethynyl)biferrocene as a Linking Group for Gold, Ruthenium, and Osmium Fragments: Synthesis, Solid State Structures, and Electrochemical, UV−Vis, and EPR Spectroscopical Studies
TL;DR: A series of organometallic mono-and disubstituted bisalkynyl biferrocenes of type (LnMC≡C)(HC≡c)bfc were synthesized from a single-crystal X-ray structure analysis, showing unsymmetrical (8) or symmetrical geometries (6, 9), with almost eclipsed conformations or approximately midway positions between the fully eclipsed and the fully staggered conformation of the bfc cyclopen as discussed by the authors.
Journal ArticleDOI
Synthesis and Characterization of Diiron Diselenolato Complexes Including Iron Hydrogenase Models
Mohammad K. Harb,Tobias Niksch,Jochen Windhager,Helmar Görls,Rudolf Holze,L. Tori Lockett,Noriko Okumura,Dennis H. Evans,Richard S. Glass,Dennis L. Lichtenberger,Mohammad El-khateeb,Wolfgang Weigand +11 more
TL;DR: Diiron diselenolato complexes have been prepared as models of the active site of [FeFe]-hydrogenases as mentioned in this paper, and treatment of Fe3(CO)12 with 1 equiv of 1,3-diselenocyanatopropane (1) in THF at reflux afforded...
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Structure and Dynamic Features of an Intramolecular Frustrated Lewis Pair
TL;DR: Di(mesityl)cyclohexenylphosphine undergoes hydroboration with Piers' borane to yield the cyclohexylene-anellated frustrated Lewis pair 5, a puckered four-membered heterocyclic core structure with a long P-B bond.
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.