scholarly journals Synthesis and Structure of Iron (II) Complexes of Functionalized 1,5-Diaza-3,7-Diphosphacyclooctanes

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3775
Author(s):  
Yulia S. Spiridonova ◽  
Yulia A. Nikolaeva ◽  
Anna S. Balueva ◽  
Elvira I. Musina ◽  
Igor A. Litvinov ◽  
...  
Keyword(s):  
Solid Phase ◽  
Structural Studies ◽  
Iron Ion ◽  
X Ray Diffraction ◽  
Cationic Complex ◽  
X Ray ◽  
Carbonyl Ligands ◽  
Heteroligand Complexes ◽  
Close Proximity ◽  
Cyclic Voltammetry Method

In order to synthesize new iron (II) complexes of 1,5-diaza-3,7-diphosphacyclooctanes with a wider variety of the substituents on ligands heteroatoms (including functionalized ones, namely, pyridyl groups) and co-ligands, it was found that these ligands with relatively small phenyl, benzyl, and pyridin-2-yl substituents on phosphorus atoms in acetonitrile formed bis-P,P-chelate cis-complexes [L2Fe(CH3CN)2]2+ (BF4)2−, whereas P-mesityl-substituted ligand formed only monoligand P,P-complex [LFe(CH3CN)4]2+ (BF4)2−. 3,7-dibenzyl-1,5-di(1′-(R)-phenylethyl)-1,5-diaza-3,7-diphosphacyclooctane reacted with hexahydrate of iron (II) tetrafluoroborate in acetone to give an unusual bis-ligand cationic complex of the composition [L2Fe(BF4)]+ BF4−, where two fluorine atoms of the tetrafluoroborate unit occupied two pseudo-equatorial positions at roughly octahedral iron ion, according to X-ray diffraction data. 1,5-diaza-3,7-diphosphacyclooctanes replaced tetrahydrofurane and one of the carbonyl ligands of cyclopentadienyldicarbonyl(tetrahydrofuran)iron (II) tetrafluoroborate to form heteroligand complexes [CpFeL(CO)]+BF4−. The structural studies in the solid phase and in solutions showed that diazadiphosphacyclooctane ligands of all complexes adopted chair-boat conformations so that their nitrogen atoms were in close proximity to the central iron ion. The redox properties of the obtained complexes were performed by the cyclic voltammetry method.

Structural studies in the ruthenium(II)/(±)-ortho-Phenylenebis{methyl(phenyl)-phosphine/arsine} system. III. Crystal structures of Dichlorocarbonyl(dimethyl sulfoxide)-[ortho-phenylenebis {methyl(phenyl)phosphine}]ruthenium(II) and of cis-dicarbonyldichloro[(±)-ortho-phenylenebis{methyl(phenyl)arsine}]ruthenium(II)

1983 ◽  
Vol 36 (2) ◽  
pp. 271 ◽  
Author(s):  
SR Hall ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Diffraction Study ◽  
Dimethyl Sulfoxide ◽  
Crystal And Molecular Structure ◽  
Title Complex ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbonyl Ligands ◽  
Methyl Phenyl

The crystal and molecular structure of the title complex, cis-[Ru(CO)Cl2(dmso)(opmpp)] (1) (dmso ≡ dimethyl sulfoxide, Me2SO; opmpp ≡ (�)-ortho-phenylenebis {methyl(phenyl)phosphine},[o-C6H4(PMePh)2]), has been determined by a single-crystal X-ray diffraction study at 295(1) K, being refined to a residual of 0.050 for 6115 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 11.180(7), b 12.957(6), c 17.567(9) �, β 90.88(5)�, Z 4. The ruthenium-chlorine distances, trans to phosphine and carbonyl ligands, respectively, are 2.469(2), 2.446(2) �; the ruthenium-phosphine distances, trans to the chloride and dimethyl sulfoxide ligands, respectively, are 2.292(1), 2.313(2) �. Ruthenium-sulfur (dmso) is 2.380(2) �, while the ruthenium-carbon(CO) is c. 1.72 �. For cis-[Ru(CO)2Cl2(opmpa)] (2) (opmpa ≡ (�)-ortho-phenylenebis{methyl(phenyl)- arsine}, [o-C6H4(AsMePh)2]), refinement led to a residual of 0.036 for 2423 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 10.497(3), b 11.586(7), c 20.341(9) �, β 105.31(4)�, Z 4. Ruthenium-arsine distances, trans to carbonyl and chlorine ligands, respectively, are 2.404(1), 2.455(1) �. Ruthenium-chlorine distances, trans to arsine and carbonyl ligands, respectively, are 2.443(3), 2.433(2) �, while ruthenium-carbon(CO) distances, trans to arsine and chlorine ligands, respectively, are 1 .920(8), 1 .872(8) �.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Structural Studies on the Effects of ZrO[sub 2] Coating on LiCoO[sub 2] during Cycling Using In Situ X-Ray Diffraction Technique

2006 ◽  
Vol 153 (11) ◽  
pp. A2152 ◽  
Author(s):  
Kyung Yoon Chung ◽  
Won-Sub Yoon ◽  
James McBreen ◽  
Xiao-Qing Yang ◽  
Si Hyoung Oh ◽  
...  
Keyword(s):  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray

Wide angle X-ray diffraction study of the solid-phase chlorinated poly(ethylene)

Polymer ◽  
2004 ◽  
Vol 45 (18) ◽  
pp. 6341-6348 ◽  
Author(s):  
S. Stoeva ◽  
A. Popov ◽  
R. Rodriguez
Keyword(s):  
Diffraction Study ◽  
Solid Phase ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene

PREPARATION OF ANTIMONY-PLATINUM SURFACE ALLOY ELECTRODE BY ATOM DIFFUSION IN THE SOLID PHASE

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3999-4004
Author(s):  
HIROSHI MATSUI ◽  
KAZUFUMI WATANABE
Keyword(s):  
Diffraction Pattern ◽  
Low Temperatures ◽  
Solid Phase ◽  
Electrochemical Measurement ◽  
X Ray Diffraction ◽  
Platinum Surface ◽  
X Ray ◽  
Atom Diffusion ◽  
Heat Treated ◽  
Titanium Substrates

Antimony-platinum bilayers were prepared on titanium substrates by the two-step electrodeposition in the usual baths, and then surface alloys were formed by the atom diffusion in the solid phase. The simple antimony layer was little influenced by the substrate in both the measurements of X-ray diffraction and the i - E characteristic in a sulfuric acid solution. Regarding the bilayers, the catalytic activity in hydrogen evolution reaction was very sensitive to the presence of platinum, while the hydrogen adsorbability was quite insensitive. An interaction between antimony and platinum was confirmed by the appearance of a new dissolution wave in the electrochemical measurement and the occurrence of a new diffraction in the X-ray diffraction pattern after the heat-treatment of about 400°C. Although the new diffraction disagreed with any of the reported alloys, clear diffraction pattern of PtSb 2 alloy was observed, when the bilayers were heat-treated at about 600°C for one hour. Considering the penetration depth of X-ray, the alloying of antimony and platinum seems to occur also at low temperatures at least at the top surface.

Structural studies by x-ray diffraction of model phospholipid-insulin membranes

Biochemistry ◽  
1972 ◽  
Vol 11 (6) ◽  
pp. 945-949 ◽  
Author(s):  
R. P. Rand ◽  
S. SenGupta
Keyword(s):  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Crystallographic and optical study of LiNb1 − xTaxO3

2017 ◽  
Vol 73 (3) ◽  
pp. 498-506 ◽  
Author(s):  
S. Huband ◽  
D. S. Keeble ◽  
N. Zhang ◽  
A. M. Glazer ◽  
A. Bartasyte ◽  
...  
Keyword(s):  
Phase Transition ◽  
Lithium Niobate ◽  
Lithium Tantalate ◽  
Flux Growth ◽  
Structural Studies ◽  
Optical Study ◽  
X Ray Diffraction ◽  
Growth Technique ◽  
X Ray ◽  
Li Content

Powders of lithium niobate-tantalate across the full compositional range have been made and crystals grown using a lithium vanadate flux growth technique. The Li-content of a lithium tantalate crystal has been determined using the zero-birefringence temperature and Curie measurements, confirming the Li content is between that of congruent and stoichiometric crystals. X-ray diffraction measurements show the Nb/Ta displacement and octahedral tilt both decrease as the Ta content is increased. This also results in a decrease in the lattice parameters from lithium niobate to lithium tantalate. Birefringence measurements on the crystals as a function of temperature have been used to determine the point that the crystals become zero-birefringent, and by comparison with the structural studies have confirmed that it is not related to a phase transition and the structures remain polar through the zero-birefringence points.

Nitroxide radicals appended to phthalonitriles: synthesis, structural characterization and photophysical properties

2021 ◽  
Vol 77 (3) ◽  
pp. 137-143
Author(s):  
Ismail Fidan ◽  
Emel Onal ◽  
Catherine Hirel
Keyword(s):  
Magnetic Measurements ◽  
Photophysical Properties ◽  
Nucleophilic Aromatic Substitution ◽  
Structural Studies ◽  
Aromatic Substitution ◽  
Nitronyl Nitroxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted ◽  
Ft Ir

The syntheses of 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl-2-yl)phenoxy]phthalonitrile (3, C21H19N4O3) and 4-[4-(4,4,5,5-tetramethyl-2-imidazoline-1-oxyl-2-yl)phenoxy]phthalonitrile (4) were carried out by microwave-assisted nucleophilic aromatic substitution of 4-nitrophthalonitrile (2) by the pre-formed 2-(4-hydroxyphenyl)-4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl (1). Compounds 3 and 4 were characterized unambiguously by a rich array of analyses, such as melting point, FT–IR, MALDI–TOF MS, elemental analysis, UV–Vis, CV, EPR, magnetic measurements and single-crystal X-ray diffraction. Structural studies demonstrate that the C—H...X and C—X...π (X = O and N) interactions in the radical nitronyl nitroxide groups play an important role in the assembly of the crystal structures. Moreover, cyclic voltammetry analyses show that the phthalonitrile substituent retains the redox properties of the Ullman radicals.

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