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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Impact of intermolecular hydrogen bond on structural properties of phenylboronic acid: quantum chemical and X‐ray study
Michał K. Cyrański,Aneta Jezierska,Paulina Klimentowska,Jarosław J. Panek,Andrzej Sporzyński +4 more
TL;DR: In this article, the molecular structure and properties of phenylboronic acid were investigated experimentally using X-ray structural analysis and spectroscopic methods, and the results were enhanced by computational results concerning the geometrical and electronic structure.
Journal ArticleDOI
Highly soluble acenes as semiconductors for thin film transistors
TL;DR: In this article, the optical properties of tetracene derivatives 3, 5, 7 and 9 have been investigated by UV/Vis and fluorescence spectroscopy and their eletrochemical properties have been elucidated by cyclic voltammetry.
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Synthesis of 5-Iodopyrrolo[1,2-a]quinolines and Indolo[1,2-a]quinolines via Iodine-Mediated Electrophilic and Regioselective 6-endo-dig Ring Closure
TL;DR: Iodo derivatives of pyrrolo- and indoloquinolines allow functional group diversification on the quinoline nucleus, which proves to be highly advantageous for structural and biological activity assessments.
Journal ArticleDOI
Homochiral supramolecular M2L4 cages by high-fidelity self-sorting of chiral ligands.
TL;DR: A 1,1'-binaphthyl-based bis(pyridine) ligand was prepared in racemic and enantiomerically pure form to study the formation of [Pd2(1)4] complexes upon coordination to palladium(II) ions with regard to the degree of chiral self-sorting.
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Structural and spectral characterization of transition metal complexes of 2-pyridineformamide N(4)-dimethylthiosemicarbazone
Larissa M. Fostiak,Isabel Garcı́a,John K. Swearingen,Elena Bermejo,Alfonso Castiñeiras,Douglas X. West +5 more
TL;DR: In this paper, the crystal structures of [Ni(Am4DM)(OAc)], Ni(Am 4DM), [Ni4DM), Ni4DM, Ni5DM, [Ni5DM], [Ni6DM], Ni3CN], Ni2H2O4, [Cu4DM] and [Pt 4DM]-Cl·2H 2O are described.
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.