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

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.

1991 ◽  
Vol 46 (11) ◽  
pp. 1435-1448 ◽  
Author(s):  
Dieter Sellmann ◽  
Bernd Seubert ◽  
Wolfgang Kern ◽  
Falk Knoch ◽  
Matthias Moll

In order to study the properties of sulfur coordinated metal centres, the chromium and tungsten complexes [Cr(NO)(µ-′S4′)]2 (4), (NR4)2[W(NO)2(′S2′)2] (1) (R = Me (la), n-Bu (lb)), [W(NO)2(′S4′)] (2), [µ-O{W(NO)(′S4′)}2] (3) and [W(NPR3)(NO)(′S4′)] (5) (R = Me (5a), Et (5 b)) were synthesized (′S2′2- = 1.2-benzenedithiolate(2-); ′S4′2- = 1.2-bis(2-mercaptophenylthio)ethane(2-)). la and lb result from the reductive nitrosylation of Li2[W(′S2′)3] which was prepared by reduction of [W(′S2′)3] with n-BuLi. la was also obtained from [W(NO)2(Cl)2]n, ′S2′2- and NMe4+. Alkylation of la or lb by 1.2-dibromoethane yields 2, whose X-ray structure analysis shows that W is pseudooctahedrally coordinated by two trans thiolato S, two cis thioether S and two cis N atoms of linear W-NO groups. 2 was also obtained from [W(NO)2(CH3CN)4](BF4)2 or [W(NO)2(Cl)2]n and ′S4′2--. The reaction of [W(NO)2(Cl)2]n yielded the dinuclear oxo-bridged complex 3 as a by-product in small amounts. In preparative amounts, 3 was synthesized by hydrolysis of [W(Cl)(NO)(′S4′)]. In contrast to the analogous Mo complex, 2 does not react with N2H4; with the ligands PMe3 and PEt3, it gives the corresponding phosphiniminato complexes 5 and free phosphineoxides OPR3. In order to compare the [M(NO)2(′S4′)] complexes (M = Cr, Mo, W), the structure of [Cr(NO)2(′S4′)] was determined by X-ray structure analysis. The Cr complex exhibits the same molecular coordination geometry as 2. While growing crystals of [Cr(NO)2(′S4′)], the dinuclear Cr complex 4 was also formed. Its X-ray structure analysis shows each of the Cr centres to be coordinated pseudooctahedrally by five sulfur donors and one nitrosyl N donor. 4 was also obtained by the reaction of [Cr(CO)4(nor)] with ′S4′2- and NOBF4.


2001 ◽  
Vol 56 (7) ◽  
pp. 581-588 ◽  
Author(s):  
Dieter Sellmann ◽  
Nicole Blum ◽  
Frank W. Heinemann

The reactions of [Fe('pyS4')]2 with PMe3 , PnPr3 , N2H4 and pyridine afforded mononuclear [Fe(L)('pyS4')] complexes with L = PMe3 ( 1 ), PnPr3 (2 ), N2H4 (3) and pyridine (4). NMR spectroscopy, magnetic measurements and X-ray structure determinations revealed that all complexes exhibit frans-thiolate donors and low-spin FeII centres, irrespective of the σ-π or σ ligand character of L. In this regard, the properties of [Fe(L)('pyS4')] complexes strongly contrast with those of [Fe(L)('NHS4')] complexes ('NHS4'2- = 2 ,2 '-bis(2 -mercaptophenylthio)- diethylamine(2 -)) and indicate that the rigid py(CH2)2 entity of the 'pyS42- ligand is able to enforce trans configurations and low-spin states of complexes with [FeNS4 ] cores. In spite of their diamagnetism, confirming the absence of antibonding electrons, all complexes 1 to 4 are highly reactive and rapidly exchange their L ligands for CO to give [Fe(CO)('pyS4')]. Evidence was obtained that the oxidation of [Fe(N'-H4)('pyS4')] (3) yields the diazene complex [μ-N2 H2 {Fe('pyS4’)}2] (5).


2014 ◽  
Vol 69 (11-12) ◽  
pp. 1299-1305 ◽  
Author(s):  
Sven Krieck ◽  
Daniel Schulze ◽  
Helmar Görls ◽  
Matthias Westerhausen

Abstract The addition reactions of N,N′-bis(diphenylphosphanylmethyl)-2,3-dihydro-1H-perimidine (1) with [(cod)2Ni] and [(Ph3P)AuCl] yield yellow [(1)Ni(η4-cod)] (2) and colorless [(1)(Ph3P)AuCl]·3MeOH (3), respectively. In these transition metal complexes of nickel(0) and gold(I) 1 acts as a bidentate chelating ligand. Crystal structures of [(1)Ni(η4-cod)]·3THF (2a) and of cosolvent-free [(1)Ni(η4-cod)] (2) reveal a distorted tetrahedral environment of the nickel atom. The gold(I) atom in 3 exhibits a very long Au-Cl bond of 296.2(1) pm. In contrast to the nickel complexes, compound 3 shows strong agostic interactions between gold(I) and a methylene fragment.


1994 ◽  
Vol 49 (5) ◽  
pp. 660-664 ◽  
Author(s):  
Dieter Sellmann ◽  
Helge Friedrich ◽  
Falk Knoch

Attempts to coordinate N2H4 to [Fe(S2C6H4)2] fragments lead to N2H5[Fe(N2H4)(S2C6H4)2], which crystallizes from MeOH/N2H4 solutions as the solvate [(N2H5){Fe(N2H4)(S2C6H4)2} · 1,33 N2H4]. 1, and has been characterized by X-ray structure analysis. 1 contains three discrete N2H5+ cations, four N2H4 solvate molecules and three independent [Fe(N2H4)(S2C6H4)2]- anions which are connected via an extended network of N-H ··· N and N-H ··· S bridges. N2H5[Fe(N2H4)(S2ChH4)2] and 1 contain high-spin Fe(III) centers and labile N2H4 ligands.


1994 ◽  
Vol 49 (11) ◽  
pp. 1481-1493 ◽  
Author(s):  
Axel Fischer ◽  
Ion Neda ◽  
Peter G. Jones ◽  
Reinhard Schmutzler

4,5-Benzo-2-diethylamino-3-methyl-1,3,2-oxazaphosphorinan-6-one 1 and 4,5-benzo-2-[bis- (2-chlorethyl)amino]-3-methyl-1,3,2-oxazaphosphorinan-6-one 3 reacted with dichloro- (cycloocta-1,5-diene)platinum(II) [(COD)PtCl2] to give the ds-dichloro-platinum(II) com­plexes 2 and 4, respectively. The reaction of 1 with tricarbonyl(cycloheptatriene)molybdenum(0) led to a mixture of isomers including fac-tris-(4,5-benzo-2-diethylamino-3-methyl- 1,3,2-oxazaphosphorinan-6-one)tricarbonylmolybdenum(0) 5. The reaction of 4,5-benzo- 2-acetylamino-3-methyl-1,3,2-oxazaphosphorinan-6-one 6 with dichloro(cycloocta-1,5-diene)- platinum(II) furnished the cis-complex 7. 4,5-Benzo-2-fluoro-3-methyl-1,3,2-oxazaphosphorinan-6-one 8 reacted with both tetracarbonyl(norbornadiene)molybdenum(0) and dichloro- (cycloocta-1,5-diene)platinum(II) to form the cis-complexes 9 and 10. 31P-31P coupling con­stants from the 31P NMR spectra for the complexes 2, 4 and 9 are reported. The structures of 5, 7, 9 and 10 were established by single crystal X-ray analysis. All ligands coordinate via phosphorus only. The structure of 5 shows strongly distorted octahedral coordination geome­try associated with the presence of three bulky ligands. The Mo-P bond lengths in 5 are, for the same reason, significantly longer than in 9. The heterocycles of the ligands in 5 do not show the expected envelope conformation but are almost planar. The platinum(II) complex 7 shows crystallographic C2-symmetry, the coordination geometry at platinum being almost ideally square-planar. The same coordination geometry is observed for 10, the ligands of which possess the expected envelope conformation with phosphorus out of the plane.


1999 ◽  
Vol 73 (1-2) ◽  
pp. 7-15 ◽  
Author(s):  
María C. Rodríguez-Argüelles ◽  
Agustín Sánchez ◽  
Marisa Belicchi Ferrari ◽  
Giovanna Gasparri Fava ◽  
Corrado Pelizzi ◽  
...  

1989 ◽  
Vol 44 (8) ◽  
pp. 917-922 ◽  
Author(s):  
Wolf Peter Fehlhammer ◽  
Hans Hoffmeister ◽  
Borislav Boyadjiev ◽  
Thomas Kolrep

The X-ray structure analysis of (trans-4,5-dimethyloxazolidin-2-ylidene)triphenylboron reveals a stereochemistry of the carbene ligand which is almost identical with that in transition metal complexes. Deprotonation of triphenylboron stabilized oxazolidin-2-ylidenes with NaH leads to (oxazolin-2-ato)borates, which have been N-alkylated with [R3O+][BF4~] or RI under mild conditions.


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