Synthesis, structure determination, and hydroformylation activity of N-heterocyclic carbene complexes of rhodium

2005 ◽  
Vol 83 (6-7) ◽  
pp. 943-957 ◽  
Author(s):  
Austin C Chen ◽  
Daryl P Allen ◽  
Cathleen M Crudden ◽  
Ruiyao Wang ◽  
Andreas Decken
Keyword(s):  
Structure Determination ◽  
Phosphine Ligands ◽  
Carbene Complexes ◽  
X Ray ◽  
Branched Isomer ◽  
Very High

The effect of ancillary phosphine ligands on the structure and hydroformylation activity of Rh-N-heterocyclic carbene complexes of type [Rh(IMes)(PR3)(CO)Cl] and [Rh(SIMes)(PR3)(CO)Cl] is described. Very high selectivities for the branched isomer (>95:5) were obtained in the hydroformylation of vinylarenes in all cases except for R = OPh. The new complexes were characterized spectroscopically and by X-ray crystallography.Key words: hydroformylation, rhodium, N-heterocyclic carbene, IMes.

Crystal structure of Tris(ethane-1,2-diamine)nickel(II) diperchlorate monohydrate

1978 ◽  
Vol 31 (2) ◽  
pp. 415 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
AC Willis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Data ◽  
Structure Determination ◽  
Title Compound ◽  
Thermal Motion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Very High

The crystal structure of the title compound, [Ni(en)3] (ClO4)2,H2O, has been determined from single-crystal X-ray diffraction data at 295(1) K and refined by least squares to a residual of 0.093 for 1400 'observed' reflections. Crystals are orthorhombic, P bca, a 17.043(7), b 15.922(6), c 13.496(5) Ǻ, Z 8. The precision of the structure determination is adversely affected by very high perchlorate thermal motion. <Ni-N> is 2.13 Ǻ.

Übergangsmetall-Carbin-Komplexe, LX [1]. Neue Triphenylsilyl-Carben-Komplexe des Rheniums durch Umsetzung eines kationischen Carbinkomplexes mit Nucleophilen / Transition Metal Carbyne Complexes, LX [1] Novel Triphenylsilyl Carbene Complexes of Rhenium by Reaction of a Cationic Carbyne Complex with Nucleophiles

1980 ◽  
Vol 35 (9) ◽  
pp. 1083-1087 ◽  
Author(s):  
Ernst Otto Fischer ◽  
Paul Rustemeyer ◽  
Dietmar Neugebauer
Keyword(s):  
Transition Metal ◽  
Structure Determination ◽  
Spectroscopic Data ◽  
Reaction Conditions ◽  
Carbene Complexes ◽  
X Ray ◽  
Compound C ◽  
Carbyne Complexes

The reaction between C5H5Re(CO)3 and LiSi(C6H5)3 affords the compound C5H5(CO)2ReC(OCH3)Si(C6H5)3 after subsequent alkylation with CH3SO3F. This complex reacts with BF3 to yield [C5H5(CO)2ReCSi(C6H5)3]BF4. This cationic carbyne complex yields C5H5(CO)2ReC(CH1)Si(C6H5)3 with LiCH3 and C5H5(CO)2ReC(H)Si(C6H5)3 with (C4H9)4NBH4. Reaction conditions, properties and spectroscopic data of the new com­pounds as well as an X-ray structure determination of C5H5(CO)2ReC(H)Si(C6H5)3 are reported.

A study on α-RuCl3 crystal structure by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 30-31
Author(s):  
H.-J. Cantow ◽  
H. Hillebrecht ◽  
S. Magonov ◽  
H. W. Rotter ◽  
G. Thiele
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Scanning Tunneling Microscopy ◽  
Electron Density ◽  
Structure Determination ◽  
Electron Density Distribution ◽  
Scanning Tunneling ◽  
Monoclinic Space Group ◽  
Tunneling Microscopy ◽  
X Ray

From X-ray analysis, the conclusions are drawn from averaged molecular informations. Thus, limitations are caused when analyzing systems whose symmetry is reduced due to interatomic interactions. In contrast, scanning tunneling microscopy (STM) directly images atomic scale surface electron density distribution, with a resolution up to fractions of Angstrom units. The crucial point is the correlation between the electron density distribution and the localization of individual atoms, which is reasonable in many cases. Thus, the use of STM images for crystal structure determination may be permitted. We tried to apply RuCl3 - a layered material with semiconductive properties - for such STM studies. From the X-ray analysis it has been assumed that α-form of this compound crystallizes in the monoclinic space group C2/m (AICI3 type). The chlorine atoms form an almost undistorted cubic closed package while Ru occupies 2/3 of the octahedral holes in every second layer building up a plane hexagon net (graphite net). Idealizing the arrangement of the chlorines a hexagonal symmetry would be expected. X-ray structure determination of isotypic compounds e.g. IrBr3 leads only to averaged positions of the metal atoms as there exist extended stacking faults of the metal layers.

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Vacancy Concentration ◽  
Sodium Ion ◽  
High Ionic Conductivity ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Batteries ◽  
Ion Conducting ◽  
Very High

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Vacancy Concentration ◽  
Sodium Ion ◽  
High Ionic Conductivity ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Batteries ◽  
Ion Conducting ◽  
Very High

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>

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