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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Structural Variations and Formation Constants of First-Row Transition Metal Complexes of Biologically Active Aroylhydrazones
TL;DR: In this article, first-row transition metal (from Mn to Zn) complexes with HPCIH and 2-pyridine carbaldehyde (4'-aminobenzoyl)hydrazone (HPCAH) were synthesized and characterised.
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Tetranuclear [Cu–Ln]2 single molecule magnets: synthesis, structural and magnetic studies
TL;DR: A trianionic ligand H3L with an inner N2O2 coordination site and an oxygen atom coming from an amide function not involved in this site yields monoanionic LCu- complexes that react with Ln(hfa)3 x 2H2O (hfa = hexafluoroacetylacetonato ligand) to give dinuclear Cu-Ln complexes that self-assemble into tetranuclear species.
Journal ArticleDOI
Structural Studies of the Polymorphs of Carbamazepine, Its Dihydrate, and Two Solvates
Robin K. Harris,Phuong Y. Ghi,Horst Puschmann,David C. Apperley,Ulrich J. Griesser,Robert B. Hammond,Caiyun Ma,Kevin J. Roberts,Greg J. Pearce,Jonathan R. Yates,Chris J. Pickard +10 more
TL;DR: In this article, high-field cross-polarisation magic-angle spinning 13C NMR spectra are presented for the four known polymorphs of anhydrous carbamazepine, for a dihydrate, and for two solvates.
Journal ArticleDOI
Sterically hindered iminophosphorane complexes of vanadium, iron, cobalt and nickel: a synthetic, structural and catalytic study
Sarah Al-Benna,Mark J. Sarsfield,Mark Thornton-Pett,Daniel L. Ormsby,Peter James Maddox,Philippe Brès,Manfred Bochmann +6 more
TL;DR: In this article, the crystal and molecular structures of CoCl2{CH2(Ph2PNPh)2} and NiBr{HC(Ph 2P NC6H3Pri2} were determined.
Journal ArticleDOI
Simultaneous Recognition of a Carboxylate-Containing Ligand and an Intramolecular Surrogate Ligand in the Crystal Structure of an Asymmetric Vancomycin Dimer
TL;DR: The structure resolves a long-standing controversy about carboxylate recognition by vancomycin, suggests a possible cooperative mechanism linking ligand binding and dimerization, and demonstrates the operation of a novel intramolecular flap which occupies the binding site in the absence of ligand.
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.