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  • S ligands  (9)
  • Ruthenium  (4)
  • N-Liganden  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 341-348 
    ISSN: 1434-1948
    Keywords: N ligands ; S ligands ; Iron ; Ruthenium ; Pentadentate ligands ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to obtain iron and ruthenium complexes which are analogous to [M(L)(′NHS4′)] and [M(L)(′N2H2S3′)] complexes [′NHS4′2- = 2,2′-bis(2-mercaptophenylthio)diethylamine(2-), ′N2H2S3′2- = 2,2′-bis(2-mercaptophenylamino)diethylsulfide(2-)] but have electron-richer metal centers, the new pentadentate amine thiolate ligand ′N3H3S2′-H2 [ = 2,2′-bis(2-mercaptophenylamino)diethylamine] (4) was synthesized. The dianion ′N3H3S2′2- reacted with FeII salts to give high-spin [Fe(′N3H3S2′)] (5) [μeff (293 K) = 3.94 μB], which yielded diamagnetic [Fe(CO)(′N3H3S2′)] (6) upon reaction with CO. Complex 6 exhibits a low-frequency ν(CO) band (1934 cm-1 in THF) indicating an electron-rich Fe center and a strong Fe-CO bond. In spite of this, 6 readily dissociated in solution to 5 and CO. The reaction of [RuCl2(PPh3)3] with ′N3H3S2′2- yielded [Ru(PPh3)(′N3H3S2′)] (7), which proved inert with respect to PPh3 substitution but could be methylated at the thiolate donors. The resulting [Ru(PPh3)(′N3H3S2′-Me2)]I2 (8) proved as inert towards substitution as 7. Complex 8 could reversibly be deprotonated to give [Ru(PPh3)(′N3H2S2′-Me2)]I (11), in the course of which the [RuPN3S2] cores rearrange from CS to C1 symmetry. Reversible protonation/deprotonation was also found with [Ru(NO)(′N3H2S2′)] (9) which formed from [RuCl3(NO)(PPh3)2] and ′N3H3S2′2- in the presence of one additional equivalent of LiOMe. Protonation of 9 with HBF4 gave [Ru(NO)(′N3H3S2′)]BF4 (10). The NMR spectra and the X-ray structure analysis of 8 proved that the [RuPN3S2] cores of 7 and 8 exhibit a CS-symmetrical meso structure. In all other complexes, however, the [MLN3S2] cores exhibit a C1-symmetrical structure. It results from the fac-mer coordination mode of the ′N3H3S2′2- ligand and favors the planarization of amide donors when NH functions are reversibly deprotonated.
    Additional Material: 1 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1715-1725 
    ISSN: 1434-1948
    Keywords: Nickel complexes ; Platinum complexes ; S ligands ; C-S cleavage ; Hydride complexes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nickel and platinum complexes with tridentate ligands, having [S3] or [NS2] donor sets were investigated in order to model active sites of enzymes such as hydrogenases or CO dehydrogenases. Starting from diphenyl sulfide, a preparative synthesis was developed for ‘S3’-H2 [‘S3’-H2 = bis(2-mercaptophenyl) sulfide]. Reactions of ‘S3’-H2 or anionic ‘S3’2- with nickel and platinum precursors resulted in the formation of binuclear [Ni(‘S3’)]2 (1) and trinuclear [Pt(‘S3’)]3 (5). Complex 1 was cleaved by PMe3 or CN- to give the mononuclear complexes [Ni(‘S3’)(PMe3)] (2) and NMe4[Ni(‘S3’)(CN)] (3). Attempts to coordinate hydride to the [Ni(‘S3’)] fragment led to C-S bond cleavage of the ligand and formation of (NMe4)2[{Ni(μ-SC6H5)(S2C6H4)}2] (4). Oxidative addition of Li[‘S3’-H] to [Pt(PPh3)4] afforded the platinum hydride complexes Li[Pt(H)(‘S3’)] and Li[Pt(H)(PPh3)(‘S3’)] which, however, could not be separated from each other and yielded [Pt(‘S3’)(PPh3)] (6) when treated with MeOH. In order to investigate electronic effects of the donor set, the ‘S3’ ligand was modified by alkylation of one thiol group to give ‘RS3’-H derivatives (R = Me, Et, Cy) and by replacing a mercaptophenyl unit by an amine in ‘Et2NS2’-H [‘Et2NS2’-H = N,N-diethyl-2-(2-mercaptothiophenyl)ethylamine]. Reactions of NiII or Ni0 compounds with these ligands in a 1:1 ratio yielded the 1:2 complexes [Ni(‘MeS3’)2] (7), [Ni(‘EtS3’)2] (9) and [Ni(‘CyS3’)2] (10), with ‘RS3’- acting as bidentate ligands only. Complex 7 reversibly reacted with PMe3 to form cis-[Ni(PMe3)2(‘MeS3’)2] (8), exhibiting monodentate ‘MeS3’ ligands. [Ni(‘Et2HNS2’)2]Br2 (11) reacted reversibly with bases to presumably give octahedral [Ni(‘Et2NS2’)2]. Complexes 7, 9 and 10 also did not yield any [Ni(‘RS3’)(H)] hydride complex when treated with hydride sources. Oxidative addition of ‘CyS3’-H to [Pt(PPh3)4] yielded the hydride complexes [Pt(H)(‘CyS3’)] and [Pt(H)(PPh3)(‘CyS3’)] which, however, formed an inseparable mixture and underwent C-S bond cleavage when heated, affording [Pt(o-S2C6H4)(PPh3)2]. The molecular structures of 1, 2, 3, 5, 6, 7, and 11 were determined by X-ray crystallography, revealing butterfly-like shapes for the [MS3L] cores of the complexes.
    Additional Material: 4 Ill.
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  • 3
    ISSN: 1434-1948
    Keywords: S ligands ; P ligands ; Osmium ; Solvent effects ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In search for osmium complexes with sulfur-dominated coordination spheres that potentially bind and activate or stabilize nitrogenase relevant small molecules, several osmium-sulfur complexes containing 1,2-bis(2-mercaptophenylthio)ethane(2-) (′S4′2-) and benzenedithiolate (′S2′2-) ligands were synthesized. [OsII(PR3)2(′S4′)] [R = Ph (1), Et (2)], [OsIV(PR3)2(′S2′)2] [R = Et (3), Pr(4), Me(5), Ph(6)], [OsIV(PCy3)(′S2′)2] (7), (PHCy3)[OsIII(′S2′)2] (8a), (NMe4)[OsIII(′S2′)2] (8b), and (NBu4)2[OsIV(′S2′)3] (9b) were obtained in reactions starting from commercially available osmium compounds and the sulfur and phosphane ligands. The presence or absence of reducing solvents strongly influenced these reactions. Octahedral (3), (4), and (PHCy3)2[OsIV(′S2′)3] (9a) were characterized by X-ray structure analysis, leading to the conclusion that despite the high oxidation state of the osmium centers, innocent dithiolate ligands are present. The stabilization of the OsIV centers is traced back to S→M π donation. Close inspection of 1 and 2 revealed a large influence of the phosphane ligands on the stability of OsII thioether complexes. While 1 is reasonable stable, 2 readily gives 3 and ethylene via intramolecular ′S4′2- ligand reduction and OsIII→ OsIV oxidation. UV-Vis spectra of 3-5 indicate phosphane dissociation in solution leading to pentacoordinate [Os(PR3)(′S2′)2] complexes. This was confirmed by the synthesis of pentacoordinate [Os(PCy3)(′S2′)2] (7).
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  • 4
    ISSN: 1434-1948
    Keywords: Ruthenium ; S ligands ; Hydrazine ; Diazene ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the search for ruthenium complexes with sulfur-dominated coordination spheres that bind, activate, or stabilize nitrogenase relevant molecules, complexes containing the new and robust tetradentate ligand ‘tpS4’-H2 were synthesized. Treatment of [RuCl2(PPh3)3] with ‘tpS4’2- gives [Ru(PPh3)2(‘tpS4’)] (1), which contains two labile PPh3 ligands. The reaction of 1 with PEt3 or DMSO led to substitution of both PPh3 ligands, yielding [Ru(PEt3)2(‘tpS4’)] (2) and [Ru(DMSO)2(‘tpS4’)] (3), respectively. When treated with nitrogenous ligands, complex 1 lost only one PPh3 ligand to yield [Ru(L)(PPh3)(‘tpS4’)] complexes where L = py (7), NH3 (8), N2H4 (9), NH2NHMe (10), and CH3CN (12), all of which are labile. The labile acetonitrile complex [Ru(CH3CN)(PPh3)(‘tpS4’)] (12) proved to be particularly suited as a precursor for the syntheses of other [Ru(L)(PPh3)(‘tpS4’)] complexes. The 18 and 19 valence electron NO complexes [Ru(NO)(PPh3)(‘tpS4’)]BF4 (13) and [Ru(NO)(PPh3)(‘tpS4’)] (14), (NEt4)[Ru(N3)(PPh3)(‘tpS4’)] (15), [Ru(I)(PPh3)(‘tpS4’)] (16), and [Ru(N3)(PPh3)(‘tpS4’)] (17) were obtained starting from complex 12. The labile mononuclear hydrazine complex [Ru(N2H4)(PPh3)(‘tpS4’)] (9) gave the dinuclear complex [μ-N2H4{Ru(PPh3)(‘tpS4’)}2] (18) by dissociation of hydrazine. The dinuclear diazene complex [μ-N2H2{Ru(PPh3)(‘tpS4’)}2] (19) was obtained by oxidation of 9 and more readily from [Ru(CH3CN)(PPh3)(‘tpS4’)] (12) and N2H2, which was generated in situ from K2N2(CO2)2 and acetic acid. The molecular structures of 7, 13, 16, 18, and 19 were determined by X-ray structure analyses. The complexes 18 and 19 represent the first complexes containing the hydrazine/diazene couple, which enables us to compare both the bonding features and the formation of N-H···S bridges when hydrazine and diazene bind to transition metal sulfur sites.
    Additional Material: 5 Ill.
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  • 5
    ISSN: 1434-1948
    Keywords: Cleavage reactions ; C-S cleavage ; Ligand synthesis ; Osmium ; Ruthenium ; S ligands ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In search of a tetradentate thioether thiolate ligand that is more stable toward reductive C-S bond cleavage than the parent ligand ′S4′-H2 [′S4′-H2 = 1,2-bis(2-mercaptophenylthio)ethane], the novel tris-phenylene ligand ′tpS4′-H2 (3) [′tpS4′-H2 = 1,2-bis(2-mercaptophenylthio)phenylene] was synthesized via the nitro and amine compounds ′tpS2(NO2)2′ (1) and ′tpS2(NH2)2′ (2). The coordination of ′tpS4′2- to ruthenium centers resulted in the formation of six-coordinate [Ru(L)(PR3)(′tpS4′)] complexes (R = Et, L = PEt34; R = Ph, L = PPh35, CO 6, DMSO 7). The X-ray structure analyses of 4 and 6 revealed that the thiolate donors occupy trans positions; consequently the ′tpS4′2- ligand coordinates in the same way as the ′S4′2- ligand. The stability of the ′tpS4′2- ligand toward reductive C-S cleavage reactions was shown by the synthesis of [Os(PEt3)2(′tpS4′)] (8). In contrast to [Os(PEt3)2(′S4′)], 8 is stable for unlimited periods of time. The X-ray structure analysis of [Ru(Cl)2(PPh3)(′tpS2(NH2)2′)] (9) demonstrates that the potentially tetradentate ligand ′tpS2(NH2)2′ coordinates in 9 through three donors leaving one NH2 donor dangling.
    Additional Material: 1 Ill.
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  • 6
    ISSN: 1434-1948
    Keywords: Ruthenium ; Sulfur ligands ; Exchange reactions ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In a quest for ruthenium complexes having [RuNS4] cores, a non-fluxional configuration, trans-thiolate donors, and exchangeable coligands L, [Ru(L)(‘pyS4’)] complexes have been synthesized [‘pyS4’2- = 2,6-bis(2-mercaptophenylthio)dimethylpyridine(2-)]. Treatment of [RuCl2(PPh3)3] with ‘pyS4’2- gave [Ru(PPh3)(‘pyS4’)] (1). Alkylation of 1 with excess MeI yielded [Ru(PPh3)(‘pyS4’-Me2)]I2 (2). [Ru(DMSO)(‘pyS4’)] (3) was obtained from [RuCl2(DMSO)4] and ‘pyS4’2-. The PPh3 or DMSO coligands in 1, 2, and 3 proved to be very inert to substitution. Only the DMSO could be displaced by CO under drastic conditions yielding [Ru(CO)(‘pyS4’)] (4). Treatment of [RuCl2(CH3CN)4] with ‘pyS4’2- yielded [Ru(‘pyS4’)]2 (5); in the presence of PEt3 or N2H4 mononuclear [Ru(PEt3)(‘pyS4’)] (6) and [Ru(N2H4)(‘pyS4’)] (7) were formed. Template alkylation of NBu4[Ru(NO)(S2C6H4)2] with 2,6-bis(tosyloxymethyl)pyridine gave [Ru(NO)(‘pyS4’)]Tos (8). Complex 8 proved to be the best suited precursor for L exchange reactions. Under reducing conditions, 8 releases its NO ligand and the resulting [Ru(‘pyS4’)] fragments can combine either with each other to give 5, or with PEt3 and N2H4 to yield 6 and 7, respectively. All complexes have been characterized by spectroscopic methods and elemental analysis; 1, 2, 3, and 4 have also been submitted to X-ray structure analysis.
    Additional Material: 2 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 271-279 
    ISSN: 1434-1948
    Keywords: Nickel complexes ; Palladium complexes ; S ligands ; Exchange reactions ; Azide ; Sulfinylimide ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to obtain suitable precursors for nickel and palladium complexes that model the reactivity of the active sites of hydrogenases and CO dehydrogenases, a series of [M(L)(‘S3’)] complexes has been synthesized [M = NiII, PdII; ‘S3’2- = bis(2-mercaptophenyl)sulfide(2-)]. X-ray structure determinations of [Ni(‘S3’)]3 (1) and [Pd(‘S3’)]3 (2) have revealed that the [M(‘S3’)] fragments trimerize to give six-membered [MS]3 rings, which exhibit chair conformations with alternating MII centers and thiolate bridging atoms. Reactions of the parent complex [Ni(‘S3’)]3 (1) with nucleophiles L, such as thiolates SR- (R = tBu, Cy, Me, Ph), phosphanes PR3 (R = Cy, Ph), chloride, or azide, have been found to yield the corresponding anionic or neutral [Ni(L)(‘S3’)] complexes, which were isolated as (NBu4)[Ni(SR)(‘S3’)] [R = tBu (3), Cy (4), Me (5), Ph (6)], [Ni(PR3)(‘S3’)] [R = Cy (7), Ph (8)], (NBu4)[Ni(Cl)(‘S3’)] (9), and (NBu4)[Ni(N3)(‘S3’)] (10). When treated with Me3SiX, the StBu- ligand in (NBu4)[Ni(StBu)(‘S3’)] (3) was exchanged to give (NBu4)[Ni(X)(‘S3’)] [X = Cl- (9), N3- (10), NCS- (11), NSO- (12)]. The palladium complex [Pd(‘S3’)]3 (2) could also be cleaved with StBu-, but the resulting (NBu4)[Pd(StBu)(‘S3’)] (13) proved inert towards exchange reactions with Me3SiX. All the mononuclear complexes have been characterized by standard spectroscopic techniques and by elemental analysis. The molecular structures of 3, 4, 6, 7, 8, 9, and 13 have been determined by X-ray crystallography. The [MS3L] core geometries of all the complexes are non-planar, exhibiting a considerable tetrahedral distortion.
    Additional Material: 5 Ill.
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  • 8
    ISSN: 0947-6539
    Keywords: dihydrogen activation ; heterolytic cleavage ; hydrido complexes ; rhodium ; S ligands ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [Rh(H)(L)(“buS4”)] complexes (L = CO (1), PCy3 (2); “buS4”2- = 1,2-bis[(2-mercapto-3,5-di-tert-butylphenylthio)ethane2-]) catalyze the D2/H+ exchange between D2 and EtOH protons in the presence of catalytic amounts of Brønsted acids. A mechanism and complete cycle for the heterolytic D2 cleavage are proposed that are based on characterization of key intermediates and monitoring of key reactions. The key intermediates are the thiol hydride complexes [Rh(H)(L)(“buS4”-H)]BF4, L = CO (3), PCy3 (4), the coordinatively unsaturated complexes [Rh(L)(“buS4”)]BF4, L = CO (5), PCy3 (6), which are the actual catalysts, and the deuterium-labeled derivatives of 1-4. Complexes 3 and 4 form from 1 and 2 by protonation with HBF4, and they release H2 to give 5 and 6. Complex 5 dimerizes in the solid state and was characterized by X-ray structure determination of 5·8CH2Cl2 (triclinic space group P\documentclass{article}\pagestyle{empty}\begin{document}$ \bar 1 $\end{document}, a = 1048.2(4) pm, b = 1430.0(5) pm, c = 1785.7(7) pm, α = 100.49(3)°, β = 102.92(3)°; γ = 103.68(3)°, Z = 1). Complex 6 is mononuclear and adds H2O or THF reversibly to give the highly labile [Rh(L)(PCy3)(“buS4”)]BF4, L = H2O (7), THF (8). CO is irreversibly added to give the stable [Rh(CO)-(PCy3)(“buS4”)]BF4 (9), whose high-frequency ν(CO) (2081 cm-1) indicates a relatively low electron density at the Rh center. Complex 6 also adds to H2 to give 4, which can be deprotonated by solid Na2CO3 or H2O to yield neutral 2. 1H NMR and 2H NMR spectroscopy revealed the scrambling of thiol protons and hydride ligands in 3 and 4 and its deuterium-labeled derivatives. This exchange of thiol protons for hydride ligands is explained by a transient [Rh(η2-H2)] species. Low-temperature 1H/2H NMR spectroscopy showed that protonation of 2 yields four diastereomers of 4 resulting from protonation of the four stereochemically nonequivalent lone pairs at the thiolate donors of 2. The relevance of these findings to H2 activation at transitionmetal sulfur sites in hydrogenases or hydrotreatment catalysts, and differences from the H2 cleavage achieved with other complexes not containing “built-in” Brønsted-basic centers, are discussed.
    Additional Material: 5 Ill.
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  • 9
    ISSN: 0044-8249
    Keywords: Eisen ; Magnetische Eigenschaften ; Mößbauer ; Spektroskopie ; N-Liganden ; S-Liganden ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
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  • 10
    ISSN: 0044-8249
    Keywords: Eisen ; N-Liganden ; S-Liganden ; Mößbauer-Spektroskopie ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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