Imidazole/benzimidazole-modified cyclotriphosphazenes as highly selective fluorescent probes for Cu2+: synthesis, configurational isomers, and crystal structures

2017 ◽  
Vol 46 (28) ◽  
pp. 9140-9156 ◽  
Author(s):  
Aylin Uslu ◽  
Süreyya Oğuz Tümay ◽  
Ahmet Şenocak ◽  
Fatma Yuksel ◽  
Elif Özcan ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Fluorescent Probes ◽  
Copper Ion ◽  
Crystallographic Analysis ◽  
Ion Detection ◽  
X Ray

We present a comprehensive work and discuss the fluoroprobe properties of synthesized compounds for copper ion detection with a stereochemical approach using X-ray crystallographic analysis results.

scholarly journals X-Ray Crystallographic Analysis, EPR Studies, and Computational Calculations of a Cu(II) Tetramic Acid Complex

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Dimitrios Matiadis ◽  
Dimitrios Tsironis ◽  
Valentina Stefanou ◽  
Olga Igglessi–Markopoulou ◽  
Vickie McKee ◽  
...  
Keyword(s):  
Self Assembly ◽  
Copper Ions ◽  
Copper Ion ◽  
Spectroscopic Properties ◽  
Crystallographic Analysis ◽  
Computational Techniques ◽  
Tetramic Acid ◽  
Acid Complex ◽  
X Ray ◽  
Computational Calculations

In this work we present a structural and spectroscopic analysis of a copper(II) N-acetyl-5-arylidene tetramic acid by using both experimental and computational techniques. The crystal structure of the Cu(II) complex was determined by single crystal X-ray diffraction and shows that the copper ion lies on a centre of symmetry, with each ligand ion coordinated to two copper ions, forming a 2D sheet. Moreover, the EPR spectroscopic properties of the Cu(II) tetramic acid complex were also explored and discussed. Finally, a computational approach was performed in order to obtain a detailed and precise insight of product structures and properties. It is hoped that this study can enrich the field of functional supramolecular systems, giving place to the formation of coordination-driven self-assembly architectures.

Intramolecular Hydrolysis of Coordinated Acetonitrile in a Binuclear Complex of Cobalt(III): X-Ray Crystallographic Analysis of Salts of [(tren)Co(μ-NH2,μ-L)Co(tren)]4+(L=OH, CH3C(O)NH)

1990 ◽  
Vol 43 (4) ◽  
pp. 643 ◽  
Author(s):  
NW Alcock ◽  
II Creaser ◽  
NJ Curtis ◽  
L Roecker ◽  
AM Sargeson ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Binuclear Complex ◽  
Binding Mode ◽  
Crystallographic Analysis ◽  
Bridging Ligands ◽  
X Ray ◽  
Hydrolysis Of

A synthesis of [( tren )Co(μ-NH2,μ-OH)Co( tren )]4+(3)( tren = tris (2- aminoethyl )amine) is reported along with a series of derivatives: [( tren ) XCo (μ-NH2) CoX ( tren )]n+, where X = CF3SO3- (n = 3)(4), X = CH3CN (n = 5)(5), and [( tren )Co(μ-NH2,μ-CH3C(O)NH)Co( tren )]4+ (6). The substitution of (4) by CH3CN to yield (5) was studied in CH3CN at 20°C, k = 9.0×10-3 s-1, and the intramolecular hydrolysis of (5) to yield the bridging acetamide complex (6) was studied at various acid concentrations. The X-ray crystal structures were determined for (3b) (exafluorophosphate, dihydrate) and (6b) (dithionate, tetrahydrate ). Both crystals are monoclinic, respectively P21/n with a 11.082(2), b 10.402(2), c 15.611(2)Ǻ, β 99.13(2)°, Z 2, and C2/c with a 14.328(2), b 14.046(1), c 16.497(2)Ǻ, β 101.90(1)°, Z 4. For the salt of (3), 2389 data with 1 ≥ 2σ(I) were refined to R 0.070 ( Rw 0.066), and, for the salt of (6), 3087 data with I ≥ 3σ(I) were refined to R 0.041 ( Rw 0.056). Both ions lie on pseudo-symmetric sites involving disorder of the bridging ligands . The structures establish the binding mode of the acetamido ion and the orientation of the tren groups in the isolated complexes.

Chemistry and crystal structures of tetrabenzoylethylene, its photolysis product and tetraacetylethylene

1978 ◽  
Vol 31 (6) ◽  
pp. 1265 ◽  
Author(s):  
JR Cannon ◽  
VA Patrick ◽  
CL Raston ◽  
AH White
Keyword(s):  
Solid State ◽  
Crystal Structures ◽  
Molecular Conformation ◽  
Crystallographic Analysis ◽  
Stable Form ◽  
Photolysis Product ◽  
Molecular Conformations ◽  
X Ray ◽  
The Difference ◽  
The Stability

X-ray crystallographic analysis has revealed that the light-sensitive form (A) and the light-stable form (A') of tetrabenzoylethylene are not valence tautomers but are two crystalline modifications of the same substance. The difference in the stability of these forms to light appears to be a consequence of their different molecular conformations and packing in the solid state. The molecular conformation of the A form is represented by (8) and that of the A' form by (9). The related tetraacetylethylene has the conformation (10) in the solid state. X-ray crystallographic analysis has also revealed that the photolysis product (B) of tetrabenzoylethylene is 4-phenoxy-3,4,6-triphenyl-1H,4H-furo[3,4-c]-furan-1-one (11). ��� The crystal structures of (8), (9), (10) and (11) were determined by X-ray diffraction: diffractometer data at 295 K were refined by least-squares techniques to residuals of 0.064 (2161 'observed' reflections) for (8), 0.057 (1310) for (9), 0.049 (1295) for (10) and 0.061 (1639) for (11). Crystals of (8) are monoclinic, P21/n, a 8.775(5), b 17.352(9), c 30.985(8)Ǻ, β 93.01(3)°, Z 8. Crystals of (9) which contain carbon disulfide are monoclinic, A2/a, a 21.21(2), b 6.181(4), c 20.35(2) Ǻ, β 102.77(7)°, Z 4. Crystals of (10) are monoclinic, P21/n, a 7.540(2), b 4.392(2), c 14.770(4) Ǻ, β 96.29(2)°, Z 2. Crystals of (11) are monoclinic, P1/n, a 14.820(4), b 15.000(3), c 10.819(4)Ǻ, β 106.02(2)°, Z 4.

Stereoselective synthesis and X-ray crystallographic analysis of mixed 6,6-dihalo penicillanates

1985 ◽  
Vol 63 (11) ◽  
pp. 3177-3181 ◽  
Author(s):  
Diego U. Belinzoni ◽  
Oreste A. Mascaretti ◽  
Pedro M. Alzari ◽  
Graciela Punte ◽  
Carlos Faerman ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Stereoselective Synthesis ◽  
Crystallographic Analysis ◽  
Displacement Reaction ◽  
X Ray ◽  
Single Crystal Analysis

The pivaloyloxy methyl 6,6-dihalo penicillanates 1a, 1b, and 1c have been stereoselectively prepared from the reaction of pivaloyloxy methyl 6-diazo penicillanate 2 with either N-halosuccinimide/halide or the interhalogens Xl (X = Cl, Br). The crystal structures of 3S,5R,6R pivaloyloxy methyl 6-bromo, 6-chloro penicillanate1a; 3S,5R,6R pivaloyloxy methyl 6-iodo, 6-bromo penicillanate 1b, and 3S, 5R, 6R pivaloyloxymethyl 6-iodo, 6-chloro penicillanate 1c have been determined by X-ray single crystal analysis. The stereochemistry of the displacement reaction is discussed.

scholarly journals Frq2 fromDrosophila melanogaster: cloning, expression, purification, crystallization and preliminary X-ray analysis

2014 ◽  
Vol 70 (4) ◽  
pp. 530-534 ◽  
Author(s):  
Soledad Baños-Mateos ◽  
Antonio Chaves-Sanjuán ◽  
Alicia Mansilla ◽  
Alberto Ferrús ◽  
María José Sánchez-Barrena
Keyword(s):  
Nervous System ◽  
Drosophila Melanogaster ◽  
Crystal Structures ◽  
Calcium Binding ◽  
Crystallographic Analysis ◽  
Differential Function ◽  
Crystal Forms ◽  
X Ray ◽  
Seeding Method ◽  
Chromatographic Procedure

Drosophila melanogastercontains two calcium-binding proteins, Frq1 and Frq2, in the nervous system that control the number of synapses and the probability of release. To understand the differential function of the two proteins, whose sequence is only 5% dissimilar, the crystal structures of Frq1 and Frq2 are needed. Here, the cloning, expression, purification, crystallization and preliminary crystallographic analysis of Frq2 are presented. The full-length protein was purified using a two-step chromatographic procedure. Two different diffracting crystal forms were obtained using a progressive streak-seeding method and detergents.

scholarly journals Syntheses and Crystal Structures of and

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Takayoshi Fujii ◽  
Mihoko Kanno ◽  
Mitsuo Hirata
Keyword(s):  
Crystal Structures ◽  
Crystallographic Analysis ◽  
Planar Geometry ◽  
Distorted Tetrahedron ◽  
X Ray ◽  
Trinuclear Complexes ◽  
Square Planar

We have prepared the trinuclear complexes (3) and (4), from the reaction of with (1) and determined their structures by X-ray crystallographic analysis. In both complexes, two monoanions chelate the Cu(II) center in square-planar geometry, whereas the terminal Cu(II) center is four-coordinate and a distorted tetrahedron.

scholarly journals Crystal Structure of Burgess Inner Salts and their Hydrolyzed Ammonium Sulfaminates

2019 ◽  
Vol 72 (11) ◽  
pp. 867 ◽  
Author(s):  
Anthony J. Arduengo III ◽  
Yosuke Uchiyama ◽  
David A. Dixon ◽  
Monica Vasiliu
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crystal Structures ◽  
Ethyl Ester ◽  
Crystallographic Analysis ◽  
Water Soluble ◽  
X Ray ◽  
Dative Bond ◽  
Solid State Structures

The solid-state structures of the Burgess reagent, and its analogous ethyl ester reveal structures indicative of triethylamine solvated sulfonyl imides rather than the more commonly depicted triethylammonium sulfonyl amidate. The existence of a reversibly formed hydrate of Burgess reagent is not supported by present studies, but rather a hydrosylate that does not revert to the Burgess reagent with gentle warming under vacuum was isolated and characterised. Structures of the hydrosylates from both the methyl- and ethyl-amidate esters were determined from X-ray crystallographic analysis and are reported. The crystal structures of the Burgess inner salts exhibit geometries at the sulfur atoms that are intermediate between a planar O2S=NCO2R unit and tetrahedral 4-coordinate sulfur centres that would be expected from a strong single (dative) bond between the triethylamine nitrogen and sulfur. The hydrolysed ammonium sulfaminates are water soluble intermolecular salts composed of triethylammonium ions, Et3NH+, and N-(alkoxycarbonyl)sulfaminate, O(−)SO2NHCO2R {R=CH3 or C2H5}.

scholarly journals Synthesis and Crystal Structures of 4,5-Dihydroimidazo[1,5-b]pyrazol-6-ones

SynOpen ◽  
2020 ◽  
Vol 04 (04) ◽  
pp. 71-83
Author(s):  
Antonio Guirado ◽  
María Vera ◽  
Bruno Martiz ◽  
Francisco Ródenas ◽  
José A. Sandoval ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Hydrogen Chloride ◽  
Pyrazole Ring ◽  
Crystallographic Analysis ◽  
Ring System ◽  
X Ray ◽  
One Step ◽  
Chloride Elimination

AbstractThe synthesis of previously unattainable 2,5-disubstituted 4,5-dihydroimidazo[1,5-b]pyrazol-6-ones has been developed. Electrochemical reductions of readily available 2,2,2-trichloroethylideneacetophenones were followed by reaction with hydrazine, leading to 3-aryl-5-dichloromethyl-2-pyrazolines. These were treated with isocyanates to obtain the corresponding aminocarbonyl derivatives, which were found to be able to form an otherwise almost inaccessible imidazo[1,5-b]pyrazole ring system via a one-step reaction involving internal condensation followed by hydrogen chloride elimination and aromatization. The molecular­ structures of 2-(4-methylphenyl)-5-tosyl-4,5-dihydro­imidazo[1,5-b]pyrazol-6-one, 5-dichloromethyl-N-(4-chlorophenyl)-4,5-dihydro-3-p-tolylpyrazole-1-carboxamide, and 5-(4-bromophenyl)-2-p-tolyl-4,5-dihydroimidazo[1,5-b]pyrazol-6-one were determined by X-ray crystallographic analysis.

The synthesis and reactivity of α-oxosulfines

1989 ◽  
Vol 67 (3) ◽  
pp. 369-381 ◽  
Author(s):  
Ian W. J. Still ◽  
Donald V. Frazer ◽  
Donna K. T. Hutchinson ◽  
Jeffery F. Sawyer
Keyword(s):  
Crystal Structures ◽  
Reaction Pathway ◽  
Reactive Intermediates ◽  
Crystallographic Analysis ◽  
Diels Alder ◽  
Electrophilic Addition ◽  
X Ray ◽  
Major Reaction ◽  
Sulfenic Acids

Thiochroman-4-one and cyclohexanone have been converted into the corresponding α-oxosulfines and the behaviour of these reactive intermediates with a range of alkenes and alkynes has been examined. In contrast to some earlier work, the major reaction pathway does not involve formation of the initially expected Diels–Alder adducts but instead a series of adducts involving electrophilic addition to the alkene or alkyne, with concomitant deoxygenation and incorporation of chlorine. The structures of these adducts have been determined by the usual spectroscopic means and, in two representative cases, by X-ray crystallographic analysis. The crystal structures, which include unusual features such as relatively short S … O nonbonding contacts, are discussed in detail. Keywords: (α-oxo)sulfines, sulfenic acids, X-ray analysis, electrophilic addition.

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

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