Zinc halide oxazoline complexes — The quest for structural diversity

2009 ◽  
Vol 87 (1) ◽  
pp. 368-379 ◽  
Author(s):  
Robert A Gossage ◽  
Paras N Yadav ◽  
Timothy D MacInnis ◽  
J Wilson Quail ◽  
Andreas Decken
Keyword(s):  
Single Crystal ◽  
Structural Diversity ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
Neutral Donor ◽  
Donor Ligand ◽  
X Ray ◽  
Distorted Tetrahedral Coordination ◽  
Secondary Bonding

The synthesis and characterization of 14 ZnX2 (X = Cl or Br) complexes containing aryl-oxazoline (ox) ligands is reported. Eleven of these derivatives have been structurally elucidated in the solid state by single crystal X-ray diffraction methods. The ligands used are 2-(3-R-phenyl)-2-oxazoline (R = Cl or Me), 2-(4-R-phenyl)-2-oxazoline (R = Cl, F, Me or –OMe), and 2-(anisol-2-yl)-4,4-dimethyl-2-oxazoline (7a). All oxazolines, with the exception of 7a, lead to the formation of materials identified as ZnX2(ox)2 upon reaction with ZnX2. A distorted tetrahedral coordination motif around the Zn metal centre is displayed in nine examples that have been characterized by single crystal X-ray diffraction methods. In the case of ligand 7a, an unusual dimeric species (X-ray) of formula [ZnCl2(7a)]2 (7b) is formed upon reaction with ZnCl2. Compound 7b displays a rare (formally neutral) µ-(Cl)2-(Zn[L]Cl)2 (L = neutral donor ligand) unit in addition to secondary bonding interactions between the Zn centres and the O-atom of the –OMe group (Zn···O distance of ~2.56 Å). In contrast, reactions of 7a with ZnBr2 lead to the formation of a monomeric species containing a chelating molecule of 7a with binding through the oxazoline N-atom and the methoxy (Zn–O distance of ~2.14 Å) group, i.e., ZnBr2(7a-κ2N,OOMe). These complexes are discussed in terms of structurally related Zn species and some comment is made as to the direction to be explored within this series of materials that may lead to further unusual structural diversity.Key words: oxazoline, oxazole, zinc, X-ray crystal structure, coordination complex, Zn(II) halide.

Oxazoline chemistry — Part IV: Synthesis and characterization of oxazoline complexes of the zinc halides

2003 ◽  
Vol 81 (12) ◽  
pp. 1482-1491 ◽  
Author(s):  
Tosha M Barclay ◽  
Ignacio del Río ◽  
Robert A Gossage ◽  
Sarah M Jackson
Keyword(s):  
Crystal Structure ◽  
Structural Diversity ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
Zinc Compounds ◽  
X Ray ◽  
H Nmr ◽  
Oxazoline Ligands

The synthesis and characterization of 11 zinc halide derivatives that contain monodentate oxazoline ligands is described. The treatment of ether solutions of [ZnX2] (X = Cl, Br, I) with 2-aryl- or 2-methyl-2-oxazolines results in the formation of mildly hygroscopic complexes of the general formulae [ZnX2(ox)2] (ox = 2-methyl-2-oxazoline (1), 2,4,4-trimethyl-2-oxazoline (2), 2-phenyl-2-oxazoline (3), or 4,4-dimethyl-2-phenyl-2-oxazoline (4)), except in the case of ZnI2, which does not form an isolable complex — likely for steric reasons — with oxazoline 4. Treatment of [ZnBr2(4)2] with 1 reveals (1H NMR) that 1 only sluggishly displaces coordinated 4 at temperatures below 50 °C. The structural characterization, via single crystal X-ray diffraction, of six of the complexes, viz. [ZnI2(1)2], [ZnI2(2)2], [ZnX2(3)2] (X = Cl, Br, or I), and [ZnBr2(4)2], is also reported. All of these structurally characterized complexes are mononuclear zinc compounds with an overall distorted tetrahedral arrangement of the two halide and two oxazoline ligands around the zinc metal centre. The oxazoline series of complexes reported herein show little structural diversity, a facet which is in contrast to their substituted pyridine analogues.Key words: oxazoline, zinc, X-ray crystal structure, coordination complex, NMR spectroscopy, Zn(II).

scholarly journals After 200 Years: The Structure of Bleach and Characterization of Hypohalite Ions by Single‐Crystal X‐Ray Diffraction

2021 ◽  
Author(s):  
Filip Topić ◽  
Joseph M. Marrett ◽  
Tristan H. Borchers ◽  
Hatem M. Titi ◽  
Christopher J. Barrett ◽  
...  
Keyword(s):  
Single Crystal ◽  
X Ray Diffraction ◽  
X Ray

Synthesis and Characterization of Tetraphenylphosphonium Tetraazidoborate

2002 ◽  
Vol 57 (6) ◽  
pp. 621-624 ◽  
Author(s):  
Wolfgang Fraenk ◽  
Heinrich Nöth ◽  
Thomas M. Klapötke ◽  
Max Suter
Keyword(s):  
Single Crystal ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray

AbstractTetraphenylphosphonium tetraazidoborate, [P(C6H5)4][B(N3)4], was obtained from B(N3)3 - in situ prepared from BH3 · O(C2H5)2 and HN3 - and [P(C6H5)4][N3]. Recrystallization from an acetonitrile / hexane mixture yielded colorless crystals in 60% yield. The molecular structurewas determined by single crystal X-ray diffraction and the [B(N3)4]- anionwas shown to possess S4 symmetry.

scholarly journals Serendipitous formation and characterization of K2[Pd(NO3)4]·2HNO3

2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Monoclinic Space Group ◽  
Solvothermal Process ◽  
X Ray Diffraction ◽  
Glass Ampoule ◽  
Space Group ◽  
X Ray ◽  
Complex Anions

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.

Synthesis of ReItricarbonyl complexes with various sulfur- and oxygen-donating ligands: crystal structures of two ReIdinuclear structures bridged by S atoms

2018 ◽  
Vol 74 (10) ◽  
pp. 1116-1122
Author(s):  
Pheello I. Nkoe ◽  
Hendrik G. Visser ◽  
Chantel Swart ◽  
Alice Brink ◽  
Marietjie Schutte-Smith
Keyword(s):  
Hydrogen Bond ◽  
Intermolecular Hydrogen Bond ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
Pyridine Ligand ◽  
X Ray ◽  
Hydrogen Bond Interactions ◽  
Mononuclear Complexes

The synthesis and characterization of two dinuclear complexes, namelyfac-hexacarbonyl-1κ3C,2κ3C-(pyridine-1κN)[μ-2,2′-sulfanediyldi(ethanethiolato)-1κ2S1,S3:2κ3S1,S2,S3]dirhenium(I), [Re2(C4H8S3)(C5H5N)(CO)6], (1), and tetraethylammoniumfac-tris(μ-2-methoxybenzenethiolato-κ2S:S)bis[tricarbonylrhenium(I)], (C8H20N)[Re2(C7H7OS)3(CO)6], (2), together with two mononuclear complexes, namely (2,2′-bithiophene-5-carboxylic acid-κ2S,S′)bromidotricarbonylrhenium(I), (3), and bromidotricarbonyl(methyl benzo[b]thiophene-2-carboxylate-κ2O,S)rhenium(I), (4), are reported. Crystals of (1) and (2) were characterized by X-ray diffraction. The crystal structure of (1) revealed two Re—S—Re bridges. The thioether S atom only bonds to one of the ReImetal centres, while the geometry of the second ReImetal centre is completed by a pyridine ligand. The structure of (2) is characterized by three S-atom bridges and an Re...Re nonbonding distance of 3.4879 (5) Å, which is shorter than the distance found for (1) [3.7996 (6)/3.7963 (6) Å], but still clearly a nonbonding distance. Complex (1) is stabilized by six intermolecular hydrogen-bond interactions and an O...O interaction, while (2) is stabilized by two intermolecular hydrogen-bond interactions and two O...π interactions.

scholarly journals Cloning, Expression, Purification, and Preliminary Characterization of Single-Crystal X-Ray Diffraction of Glucosyltransferase B of Streptococcus mutans

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984933
Author(s):  
Joshua L. Mieher ◽  
Norbert Schormann ◽  
Manisha Patel ◽  
Hui Wu ◽  
Champion Deivanayagam
Keyword(s):  
Dental Caries ◽  
Oral Cavity ◽  
Single Crystal ◽  
Streptococcus Mutans ◽  
Tooth Enamel ◽  
Tooth Surface ◽  
X Ray Diffraction ◽  
Persistent Disease ◽  
X Ray

Dental caries characterized by acid damage of tooth enamel is a persistent disease that begins with the formation of biofilms on the tooth surface. The secreted glucosyltransferases enable Streptococcus mutans to synthesize extracellular glucan polymers using ingested starch within the oral cavity, which eventually results in the production of acid, a contributing factor to cariogenesis. In this paper, we report the cloning, expression, purification, crystallization, and preliminary X-ray diffraction characterization of glucosyltransferase B.

scholarly journals Photoreversible interconversion of a phytochrome photosensory module in the crystalline state

2019 ◽  
Vol 117 (1) ◽  
pp. 300-307 ◽  
Author(s):  
E. Sethe Burgie ◽  
Jonathan A. Clinger ◽  
Mitchell D. Miller ◽  
Aaron S. Brewster ◽  
Pierre Aller ◽  
...  
Keyword(s):  
Single Crystal ◽  
Blue Light ◽  
Green Light ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Major Barrier ◽  
X Ray ◽  
Spectroscopic Analyses ◽  
Serial Femtosecond Crystallography

A major barrier to defining the structural intermediates that arise during the reversible photointerconversion of phytochromes between their biologically inactive and active states has been the lack of crystals that faithfully undergo this transition within the crystal lattice. Here, we describe a crystalline form of the cyclic GMP phosphodiesterases/adenylyl cyclase/FhlA (GAF) domain from the cyanobacteriochrome PixJ inThermosynechococcus elongatusassembled with phycocyanobilin that permits reversible photoconversion between the blue light-absorbing Pb and green light-absorbing Pg states, as well as thermal reversion of Pg back to Pb. The X-ray crystallographic structure of Pb matches previous models, including autocatalytic conversion of phycocyanobilin to phycoviolobilin upon binding and its tandem thioether linkage to the GAF domain. Cryocrystallography at 150 K, which compared diffraction data from a single crystal as Pb or after irradiation with blue light, detected photoconversion product(s) based on Fobs− Fobsdifference maps that were consistent with rotation of the bonds connecting pyrrole rings C and D. Further spectroscopic analyses showed that phycoviolobilin is susceptible to X-ray radiation damage, especially as Pg, during single-crystal X-ray diffraction analyses, which could complicate fine mapping of the various intermediate states. Fortunately, we found that PixJ crystals are amenable to serial femtosecond crystallography (SFX) analyses using X-ray free-electron lasers (XFELs). As proof of principle, we solved by room temperature SFX the GAF domain structure of Pb to 1.55-Å resolution, which was strongly congruent with synchrotron-based models. Analysis of these crystals by SFX should now enable structural characterization of the early events that drive phytochrome photoconversion.

REALIZATION AND CHARACTERIZATION OF e-BEAM COMPLETELY EVAPORATED BSCCO THIN FILMS

1991 ◽  
Vol 05 (18) ◽  
pp. 1203-1211 ◽  
Author(s):  
C. ATTANASIO ◽  
L. MARITATO ◽  
A. NIGRO ◽  
S. PRISHEPA ◽  
R. SCAFURO
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
Single Crystal ◽  
Critical Current ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Reliable Technique ◽  
X Ray ◽  
Eds Analysis

BSCCO thin films with T c (R = 0) higher than 80 K have been routinely prepared using a simple and reliable technique in which we completely electron beam evaporated weighted amounts of bulk pellets. The films were grown on MgO single crystal (100) substrates and showed, after an ex-situ annealing at high temperatures (840–880° C) for several hours, a strong preferential orientation with the c-axis perpendicular to the plane of the substrate. The films were characterized by Θ − 2Θ X-ray diffraction and EDS analysis and by paraconductivity and critical current measurements.

scholarly journals Further errors in polymorph identification: furosemide and finasteride

2006 ◽  
Vol 62 (4) ◽  
pp. 689-691 ◽  
Author(s):  
Sohrab Karami ◽  
Yang Li ◽  
David S. Hughes ◽  
Michael B. Hursthouse ◽  
Andrea E. Russell ◽  
...  
Keyword(s):  
Single Crystal ◽  
Incomplete Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Data Collections ◽  
Mistaken Identification

Reassessment of the reported single-crystal X-ray diffraction characterization of polymorphs of furosemide and finasteride shows that, in each case, incomplete data collections have resulted in the mistaken identification of two forms that are, in fact, identical.

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