Cleavage of a Dibenzotetraazafulvalene to Yield a Rh(I) Carbene Complex

2004 ◽  
Vol 59 (5) ◽  
pp. 544-546 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Thorsten von Fehren ◽  
Lars Wittenbecher ◽  
Roland Fröhlich
Keyword(s):  
Double Bond ◽  
Structure Analysis ◽  
Mononuclear Complex ◽  
X Ray ◽  
Carbene Complex ◽  
Square Planar

Abstract The reaction of the dibenzotetraazafulvalene C6H4(NC2H5)2C=C(NC2H5)2C6H4, 1 = 1, with [(COD)Rh(μ-Cl)2Rh(COD)] proceeds via cleavage of the C=C double bond and yields the carbene complex [(COD)RhCl(1)], 2. The X-ray structure analysis shows 2 to be a mononuclear complex with a rhodium(I) center coordinated in a slightly distorted square-planar fashion.

The Pd(II) Complex of a N,N’-Diallylbenzimidazol-2-ylidene Ligand

2004 ◽  
Vol 59 (9) ◽  
pp. 1051-1053 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Tania Pape ◽  
Christian Holtgrewe
Keyword(s):  
Structure Analysis ◽  
Mononuclear Complex ◽  
X Ray ◽  
Square Planar

The palladium(II) dicarbene complex trans-[PdBr2(L)2], 2 (L = 1,3-di-(2-propenyl)-benzimidazol- 2-ylidene) was synthesized from 1,3-di-(2-propenyl)-benzimidazolium bromide 1 and Pd(OAc)2 by in situ deprotonation. The X-ray structure analysis revealed a mononuclear complex with a palladium( II) center coordinated in a square-planar fashion by the two carbene functions and two bromo ligands.

The Pd(II) Complex of a Bidentate Di(benzimidazol-2-ylidene) Ligand

2004 ◽  
Vol 59 (5) ◽  
pp. 541-543 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Thorsten von Fehrena ◽  
Lars Wittenbecher ◽  
Roland Fröhlich
Keyword(s):  
Structure Analysis ◽  
Mononuclear Complex ◽  
X Ray ◽  
Pale Yellow ◽  
Square Planar

Abstract The pale yellow palladium(II) dicarbene complex cis-[PdI2(L)], 2 (L = 1,3-bis-(3-neopentylbenzimidazol- 2-ylidene)-2,2-dimethylpropane) was synthesized by the reaction of PdI2 with an N1,N1’- 2,2’-dimethylpropane-bridged dibenzotetraazafulvalene 1 in tetrahydrofuran. The X-ray structure analysis revealed a mononuclear complex with a palladium(II) center coordinated in a slightly distorted square-planar fashion by the bidentate carbene ligand and two iodo ligands.

The Ti(IV) Complex of a Benzannulated N-Heterocyclic Carbene

2004 ◽  
Vol 59 (3) ◽  
pp. 348-350 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Thorsten von Fehren ◽  
Roland Fröhlich
Keyword(s):  
Structure Analysis ◽  
Mononuclear Complex ◽  
Equatorial Position ◽  
X Ray ◽  
Carbene Complex ◽  
Trigonal Bipyramidal ◽  
Distorted Trigonal Bipyramidal

The yellow titanium(IV) carbene complex [TiCl4(1)], 2 (1 = N,N’-bis(2,2-dimethylpropyl)benzimidazol-2-ylidene) was synthesized by reaction of TiCl4 and the benzannulated carbene 1 in toluene. The X-ray structure analysis revealed a mononuclear complex with a titanium(IV) center coordinated in a distorted trigonal-bipyramidal fashion by the carbene ligand in an equatorial position and four chloro ligands

Übergangsmetallkomplexe mit Schwefelliganden, LXXVI Redox- und Additionsreaktionen von Nickelkomplexen mehrzähniger Thioether-Thiolat-Liganden. Röntgenstrukturanalysen von (NMe4)2[Ni(′S2′)2] und [Ni(′S4 – C3′)(PMe3)] / Transition Metal Complexes with Sulfur Ligands, LXXVI Redox and Addition Reactions of Nickel Complexes with Multidentate Thioether-Thiolato Ligands. X-Ray Structure Determinations of (NMe4)2[Ni(′S2′)2] and [Ni(′S4–C3′)(PMe3)]

1991 ◽  
Vol 46 (12) ◽  
pp. 1601-1608 ◽  
Author(s):  
Dieter Sellmann ◽  
Stefan Fünfgelder ◽  
Falk Knoch ◽  
Matthias Moll
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Structure Analysis ◽  
Transition Metal Complexes ◽  
Nickel Complexes ◽  
Addition Reactions ◽  
Coordination Geometry ◽  
X Ray ◽  
Square Planar ◽  
Structure Determinations

In order to elucidate specific properties of nickel sulfur complexes, redox and addition-elimination reactions of [Ni(′OS4')]2, [Ni(′NHS4')]2, [Ni(′S5')], [Ni('S4—C5')], and [Ni('S4—C3')] were investigated ('OS4′ 2' = 2,2'-bis(2-mercaptophenylthio)diethylether(2—), 'NHS4'2- = 2,2'-bis(2-mercaptophenylthio)diethylamine(2—), 'S5'2- = 2,2'-bis(2-mercaptophenylthio)diethylsulfide(2—), 'S4-C5'2- = 1,5-bis(2-mercaptophenylthio)pentane(2—), 'S4—C3'2- = 1,3-bis(2-mercaptophenylthio)propane(2—)).Cyclovoltammetry proves the complexes to be redox inactive between —1.4 and +0.8 V vs. NHE. Above +0.8 V the complexes are irreversibly oxidized, below —1,4 V desalkylation takes place and [Ni(′S,′)2]2- is formed. An X-ray structure analysis was carried out of (NMe4)2[Ni(′S2')2], which shows a planar anion with the Ni center in a nearly perfect square planar coordination. Distances and angles are practically identical to those in the [Ni(′S2')2-] monoanion.The complexes coordinate only phosphines as coligands, but thioether donors simultaneously decoordinate and, dependant of reaction temperature, mono- or trisphosphine complexes are formed. [Ni(′S4—C3')(PMe3)] was characterized by X-ray structure analysis and exhibits a square pyramidal coordination geometry.

scholarly journals A Salt Metathesis Route To Ruthenium Carbene Complex Isomers With Pyridine Dicarboxamide-Derived Chelate Pincer Ligands

2007 ◽  
Vol 62 (6) ◽  
pp. 783-790 ◽  
Author(s):  
Carolin Wallenhorst ◽  
Kirill V. Axenov ◽  
Joseph S. M. Samec ◽  
Roland Fröhlich ◽  
Gerhard Erker
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Pincer Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbene Complex ◽  
Related Complex

Reaction of the doubly deprotonated pyridine 2,6-dicarboxamido ligand (1) with (PCy3)2Cl2 Ru=CHPh (3a) in THF gave a mixture of (lig)(PCy3)Ru=CHPh isomers (4). The pentane soluble N,N,O-4 isomer was isolated by extraction and characterized by X-ray diffraction. The O,N, O-4 isomer was identified in the residue. Single crystals of the closely related complex (lig)(NHC) Ru=CHPh, O,N,O-5, were obtained from the reaction of 1 with (NHC)(PCy3)Cl2Ru=CHPh (3b) and used for the X-ray crystal structure analysis of the system

Darstellung und Röntgenstrukturanalyse von (DichIoro)-(1,3,5,7-tetramethyI-2,4,6,8,9,10-hexathiaadamantan)palladium(II), PdCl2(CH3)4C4S6 Preparation and X-Ray Structure Analysis of (D ichloro)-(l,3,5,7-tetram ethyl-2,4,6,8,9,10-hexathiaadam antane)palladium (II), PdCl2(CH3)4C4S6

1986 ◽  
Vol 41 (4) ◽  
pp. 409-412 ◽  
Author(s):  
Joachim Pickardt ◽  
Norbert Rautenberg
Keyword(s):  
Structure Analysis ◽  
Palladium Complex ◽  
Bond Angle ◽  
Free Ligand ◽  
Lattice Parameters ◽  
Space Group ◽  
X Ray ◽  
Chelating Ligand ◽  
Square Planar

By reaction of PdCl2(C6H5CN) 2 with 1,3,5,7-tetram ethyl-2,4,6,8,9,10-hexathiaadam antane, (CH3)4C4S6, (“TMTA”), the complex PdCl2-TMTA could be obtained. X-ray structure analyses were performed for the free ligand TMTA as well as for the adduct. Both com pounds crystallize monoclinically, space group P21/n, lattice parameters for TMTA are a= 845.9(5), b= 1225.8(7), c= 1314.8(8) pm, ß= 93.28(5)°; for PdCl2-TMTA a= 1262.3(3), b= 1376.3(4), c= 939.1(3) pm, and ß= 92.86(5)°. In the palladium complex TMTA acts as a bidentate chelating ligand. The coordination about the Pd atom is approximately square planar, but the bond angle S -Pd -S is only 76.2°

A Direct Synthesis of a Strongly Zwitterionic 6,6'-Diaminofulvalene

2014 ◽  
Vol 69 (5) ◽  
pp. 580-588 ◽  
Author(s):  
Dominic Schmid ◽  
Alexander Seyboldt ◽  
Doris Kunz
Keyword(s):  
Double Bond ◽  
Theoretical Analysis ◽  
Dft Calculations ◽  
Structure Analysis ◽  
Direct Synthesis ◽  
Exocyclic Double Bond ◽  
X Ray ◽  
One Step ◽  
Initial Route ◽  
Guanidinium Salt

Upon reaction of the dipyrido-anellated guanidinium salt 1 with one equivalent of CpNa we were able to synthesize the dipyrido-anellated diaminofulvalene 4 in one step in 33% isolated yield. This shortens the initial route that applies a literature-known fulvalene synthesis via uronium salt 3 by two steps and avoids the need for a sacrificial equivalent of CpNa. Although the X-ray structure analysis reveals a shorter exocyclic double bond than observed in the diaminofulvalene V, a theoretical analysis based upon DFT calculations shows a stronger zwitterionic character for the dipyridofulvalene 4.

Metallkomplexe von N-(Pyrrol-l-yl)salicylaldiminen und deren Strukturbestimmung mittels Röntgendiffraktometrie und Röntgenabsorptionsspektroskopie (XANES) / Metal Chelates of N -(Pyrrol-l-yl)salicylaldim ines and their Structure D eterm ination by X-Ray Structure Analysis and X -R ay Absorption Spectroscopy (XANES)

1996 ◽  
Vol 51 (6) ◽  
pp. 757-764 ◽  
Author(s):  
A. Bach ◽  
L. Beyer ◽  
T. Gelbrich ◽  
K. H. Hallmeier ◽  
C. Hennig ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Absorption Spectroscopy ◽  
Line Shape ◽  
Metal Chelate ◽  
Molecular Structures ◽  
Chelate Complexes ◽  
X Ray ◽  
3D Metals ◽  
Square Planar ◽  
X Ray Absorption

Abstract A series of three N-(pyrrol-l-yl)salicylaldim ines 1-3 has been prepared an d characterized. Their metal chelate complexes with Cu, Ni and Co are described. The molecular structures of bis[N-(pyrrol-l-yl)salicylaldim inato]copper(lI) la, bis{N-[3-(pyrrol-l-yl)propyl]- salicylaldiminato}nickel(II) 2b and tris{N-[3-(pyrrol-l-yl)propyl]salicylaldiminato}cobalt(III) 2d were determined by X-ray structure analysis. The chelates with tetracoordinated copper and nickel show a square planar coordination with the characteristic trans configuration. The chelate with hexacoordinated cobalt has a meridional coordination sphere. The complexes have also been investigated by X-ray absorption spectroscopy (X̲-ray A̲bsorption N̲ear E̲dge S̲tructure, XANES) at the K edges of the 3d metals. Analyzing the relative intensities of the Is → 3d prepeak and the K edges of the line shape, it was possible to distinguish between planar, tetrahedral and octahedral coordination of the chelates

Übergangsmetallkomplexe mit Schwefelliganden, XC Synthese, Säure/Base- und Redoxreaktionen von [Ni(′N2H2S2′)]: auf der Suche nach Modellkomplexen für die Nickelzentren in Hydrogenasen und CO-Dehydrogenasen. (′N2H2S2′′2- = 1,2-Ethandiamin-N,N′-bis(2-benzolthiolat)(2–)) / Transition Metal Complexes with Sulfur Ligands, XC. Synthesis, Acid Base and Redox Reactions of [Ni(′N2H2S2′)]: A Search for Model Complexes for the Nickel Sites in Hydrogenases and CO-Dehydrogenases. (′Ν2Η2S2′2- = 1,2-Ethanediamine-N,N′-bis(2-benzenethiolate)(2-))

1992 ◽  
Vol 47 (10) ◽  
pp. 1411-1423 ◽  
Author(s):  
Dieter Sellmann ◽  
Werner Prechtel ◽  
Falk Knoch ◽  
Matthias Moll
Keyword(s):  
Structure Analysis ◽  
Transition Metal Complexes ◽  
Redox Reactions ◽  
Schiff Base Complex ◽  
Nickel Atom ◽  
Consecutive Reaction ◽  
Model Complexes ◽  
X Ray ◽  
Square Planar ◽  
Distorted Octahedral

[Ni(′N2H2S2′)], 1, forms from Ni(II) salts and the tetradentate thiolate-amine ligand ′N2H2S2′2- (= 1,2-ethanediamine-N,N′-bis(2-benzenethiolate)(2-)) [2], or by reduction of the Schiff base complex [Ni(gma)] (gma2- = glyoxal-bis(2-mercaptoanilide(2–))) with NaBH4.Bases easily deprotonate 1 to yield the [Ni(′N2S2′)]2- dianion, which is extremely easily oxidized to give the Ni(II) monoanion [Ni(′N2S2′)]- which was isolated as [AsPh4][Ni(′N2S2′)], 4, and characterized by X-ray structure analysis. 4 contains a distorted square planar NiN2S2 core, in which two thiolate-S and two amido-N donors are surrounding the nickel atom.Deprotonation of 1 was further substantiated by H*/D+ exchange to give [Ni(′N2D2S2′)] and by alkylation. Consecutive reaction of 1 with n-BuLi and CH3I leads to fourfold methylation of 1 yielding [Ni(′N2Me2S2Me2′)I2], 8, while alkylation of 1 by CH3I in the absence of base yields [Ni(′N2H2S2Me2′)I2], 5, in which only the thiolate donors have been alkylated. X-ray structure analysis shows 8 to contain a distorted octahedral NiN2S2I2 core with two sulfur atoms occupying axial trans positions and two nitrogen and two iodine atoms occupying equatorial cis positions. 1 also forms by reaction of [Ni(CO)4] with ′N2H2S2′-H2, which is explained by a series of oxidative addition and reductive elimination reactions.Palladium and platinum homologues [Pd(′N2H2S2′)], 9 and [Pt(′N2H2S2′)], 10, were synthesized from [MC12(COD)] (M = Pd, Pt) and ′N2H2S2′-H2, and exhibit analogous reactivity as 1.

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