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  • Chemistry  (25)
  • Crystal structure  (2)
  • S-Liganden  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Crystal structure of ethyl 4-methylthio-3-phenyl-2-thioxo-2,3-dihydro-1,3-oxazole-5-carboxylate (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 237-240 
    Details
    ISSN: 1572-8854
    Keywords: Crystal structure ; 1,3-oxazoline-2-thione ; resonance structures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The title compound C13H13NO3S2 crystallizes in the triclinic space group $$P\bar 1$$ (Z=2) with lattice constantsa=8.382(2),b=10.042(2),c=10.134(2) Å, α=119.35(1)°, β=101.40(1)° and γ=90.54(1)°. The interplanar angle between the least squares planes of the 1,3-oxazoline ring and the phenyl ring amounts to 90.2°, thus hindering conjugation between the benzene and heterocyclic system. The observed bond parameters of the five-membered heterocycle suggest a significant contribution from a zwitterionic dipolar limiting structure [38.7(5)%] to the description of this ring system. The particular contributions of the resonance structures were estimated by calculations using the HOSE model on the base of the observed bond lengths.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01665176
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  • 2
    Electronic Resource
    Electronic Resource
    Chemie polyfunktioneller Moleküle, 125Part 124: Ref. Synthese und Kristallstruktur von N,N,N′,N“,N-Pentamethyl-diethylentriamin-cokoordiniertem Kalium-bis(diphenylphosphanyl)amidHerrn Prof. Dr. Gerhard Herberich zum 60. Geburtstage gewidmet. (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 141-144 
    Details
    ISSN: 0009-2940
    Keywords: Alkali metal organophosphanylamide ; Carbon-potassium bonding ; Phosphazane ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The metalation of bis(diphenylphosphanyl)amine [HN-(PPh2)2,1 with KOtBu at 95°C in toluene affords a pale yellow precipitate of potassium bis(diphenylphosphanyl)amide (3a). On addition of liquid N,N,N′,N“,N“-pentamethyldiethylenetriamine (PMDTA, 4) the precipitate dissolves in toluene at 115°C to give a yellow solution, from which yellow-green blocks of [(Ph2P)2NK·PMDTA] (3b) are obtained. X-ray analysis reveals that the coordination sphere of potassium consists of the chelating triamine ligand and [N(PPh2)2]- as N-donor as well as η1 and η2 C-donor with two phenyl fragments. No phosphorus coordination of [N(PPh2)2]- is observed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300124
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  • 3
    Electronic Resource
    Electronic Resource
    Transition Metal Complexes with Sulfur Ligands, 123[Part 122: D. Sellmann, S. Emig, F. Heinemann, F. Knoch, Angew. Chem. submitted.[ Synthesis and Reactivity of New Complexes Containing the [Ru(“S4”)] Fragment [S42- = 1,2-Bis(2-mercaptophenylthio)ethane(2-)] (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 571-579 
    Details
    ISSN: 0009-2940
    Keywords: Labile ruthenium-sulfur complexes ; S2 Complexes ; Substitution reactions ; Ligand effects ; Structure-activity relationships ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to synthesize labile and well-soluble [Ru(L)(L')(“S4”)] complexes, [Ru(CI)2(DMSO)4] was treated With “S4”-Na2 (S42- = 1,2-bis(2-mercaptophenylthio)-ethane(2-1)] yielding [Ru(DMSO)2(“S4”)] (1 which contains two labile DMSO ligands. An X-ray structural analysis of 1, verifies that both DMSO ligands are coordinated via their S atoms. The reaction of 1 with small ligands such as PR3 (R = Et, nPr, nBu) or tetrahydrothiophene (THT) leads to substitution of both DMSO ligands yielding [Ru(PR3)2(“S4”)] (R = Et 3a, nPr 3b, nBu 3c) and [Ru(THT)2(“S4”] 2, respectively, while bulky phosphane ligands such as PCy3 and PiPr3 substitute one DMSO ligand to yield [Ru(DMSO)(PR3])(“S4”] (R = iPr 4a, Cy 4b). X-ray structural analyses of [Ru(PnPr3)2(“S4”)] · 0.5 MeOH (3b · 0.5 MeOH), [Ru(PnBu3)2(S4)} (3c), and [Ru(Pme3)2(“S4”)] (3d) confirm the pseudo-octahedral coordination of the Ru centers by four Sdonors and two cis P-donors and reveal close similarities bet ween the three complexes. Comparision of the structural parameters of 3b · 0.5 MeOH, 3c and 3d with those of [Ru(PPh3)2(“MeS, 4”)] [MeS4“2” = 1,2-bis(2-mercaptophenylthio)propane(2-1)] indicates that the inertness towards substitution of 3b · 0.5 MeOH, 3c and 3d as opposed to the substitution lability of [Ru(PPh3)2(,MeS4“)] is caused by the small cone angles of the alkyl phosphanes. In the DMSO/PCy3 complex 4b both coligands are labile, and which one is substituted depends on the size of the entering ligand. The reactions of 4b with PnR3 yield [Ru(DMSO)(PR3)('S4”)] (R = nPr 4c, nBu 4d) in contrast to the reaction with CO. PMe3, and SMe2 which give [Ru(CO)(Pcy3)(“S4”)] (5b), [Ru(P-Me3)(PCy3)(“S4”)] (6, and [Ru(SMe2)(PCy3)(“S4”)] (7, respectively. In an analogous manner, the CO complexes [Ru(CO(PR3)(“S4”)] (R = iPr 5a, nBu 5c) have been obtained by treatement of 4a and 4d with CO. The reactions of 4a and 4b with S8 yielded the readily soluble μ-S2 complexes [μ-S2[Ru(PR3)(“S4”)]2] (R - iPr 8a, Cy 8b). The spectroscopi9c data of complex 8b and its cyclic voltammogram, which exhibits four quasi-reversible redox waves, indicate a strong electronic coupling of the two [Ru(PCy3)(“S4”)] fragments via the μ-S2 bridge.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300507
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  • 4
    Electronic Resource
    Electronic Resource
    Conformational Flexibility of the Square-Pyramidal Coordination Cap in a Series of Octahedral Nickel(II) Pentaamine Complexes - Magnetochemical Characterization of the Singly μ-Cl-Bridged Nickel(II) Dimer [(pyN4)Ni-Cl-Ni(pyN4)](PF6)3 [pyN4 = 2,6-Bis(1′,3′-diamino-2′-methylprop-2′-yl)pyridine] (1998)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 1041-1049 
    Details
    ISSN: 1434-1948
    Keywords: Tetrapodal pentadentate ligand ; Square pyramidal coordination cap ; Pentaamine ; Nickel(II) complexes ; Magnetochemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The architecture of the tetrapodal pentaamine ligand 2,6-bis(1′,3′-diamino-2′-methylprop-2′-yl)pyridine (pyN4, 1) allows it to coordinate to nickel(II) as a square pyramidal coordination cap. The pyridine nitrogen atom occupies an apical position of the coordination octahedron, while four equivalent pendent primary amino groups occupy the equatorial positions, with a sixth coordination site remaining for a monodentate ligand. Exchange of this ligand is facile, and a series of complexes [(1)NiX]n+ (X = OH2, OClO3, NCS, N3, {Cl-Ni(pyN4)}) has been prepared and characterised by elemental analysis, IR and UV/Vis spectroscopies (as applicable), and X-ray structure determination. While the solid state structures show varying degrees of distortion of the ligand cap 1 from C2v symmetry, a polynucleating coordination mode has not been observed. The ligand enables the synthesis of dinuclear nickel(II) complexes containing a single bridging ligand, as exemplified by the singly -chloro bridged complex [(1)Ni-Cl-Ni(1)](PF6)3. This complex has an antiferromagnetically coupled ground state of total spin ST = 0, as determined from variable-temperature magnetic susceptibility measurements.
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  • 5
    Electronic Resource
    Electronic Resource
    Electron-Rich Fe and Ru Complexes with the New Trisamine Dithiolate Ligand ′N3H3S2′-H2 [2,2′-Bis(2-mercaptophenylamino)diethylamine] (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 341-348 
    Details
    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.
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesis, Structures, and Reactions of Sulfur-Rich Nickel and Platinum Complexes with [MS3] and [MNS2] Cores (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1715-1725 
    Details
    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.
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  • 7
    Electronic Resource
    Electronic Resource
    “Embroidered” Square Pyramidal Coordination Caps for Nickel(II): Mono-, Di- and Tetrafunctionalisation of a Tetrapodal Pentadentate Ligand with an NN4 Donor Set (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 2147-2156 
    Details
    ISSN: 1434-1948
    Keywords: Tetrapodal pentadentate ligand ; Ligand periphery ; Polydentate amine complex ; Nickel ; Podand ; Schiff base ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The tetrapodal pentaamine ligand 2,6-bis(1′,3′-diamino-2′-methylprop-2′-yl)pyridine (1), which contains four equivalent primary amino groups, can be derivatised partly or completely by Schiff base condensation with suitable carbonyl compounds. The new ligands thus obtained are mononucleating, as shown by the X-ray crystal structures of their respective nickel(II) complexes. Reaction of 1 with 1 equiv. of salicylaldehyde and subsequent reduction allows the selective modification of one of the four sidearms. The resulting ligand 2 is hexadentate and uninegative in its nickel(II) complex {[(2)Ni]PF6} (3) with both the secondary amine and the phenoxide functionalities coordinated to the metal centre. The unreduced Schiff base form of the ligand, 4, does not form a complex with nickel(II) as readily, and only a small quantity of the mixed salt {[(4)Ni][(1)Ni(H2O)](Br)2(PF6)} (5)has been obtained. While the overall coordination of 4 resembles that of 2, there is considerably more strain in the appended chelate ring, due to the presence of the C=N double bond. Modification of one arm in 1 can also be achieved by condensation with 1 equiv. of acetylacetone, to give the new ligand 6 which, likewise, is hexadentate in its NiII complex {[(6)Ni](PF6)2} (7). In this case, however, the N/O-functional sidearm is not deprotonated. Rather, it is coordinated as the keto-imine tautomer, making 7 a rare example of a metal complex containing this structural fragment. Two-fold functionalisation of 1 is observed upon reaction with acetone, regardless of whether the ketone is present in stoichiometric amounts or in excess, to give the pentadentate ligand 8with two diagonally juxtaposed isopropylidene-imine units. The complex isolated with this ligand {[(8)Ni](PF6)2} (9) contains pentacoordinate NiII, the sixth coordination site being blocked by the rigidly positioned isopropylidene groups. When reacted with 4 equiv. of trans-cinnamaldehyde, all the primary amino groups in 1 condense to give the four-fold Schiff base 10, which acts as a pentadentate podand towards nickel(II). In this complex, {[(10)Ni(OH2)]Br2} (11), an aqua ligand completes the coordination octahedron. All ligands are stable towards hydrolysis when coordinated to the metal, despite the presence of alkyl-imine groups in some cases.
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  • 8
    Electronic Resource
    Electronic Resource
    Synthesis and X-Ray Structures of Novel Lead(1+) and Indium(3+) Phosphazenide Complexes; Detailed 207Pb-NMR Spectra of the 207Pb-Labelled Dimeric Lead(1+) Species (1998)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 437-444 
    Details
    ISSN: 1434-1948
    Keywords: Lead(1+) ; Indium(3+) ; Organylphosphanylamide complexes ; Phosphazene ; 207Pb-NMR spectra ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of PbCl2 with LiN(PPh2)2 (1) at -78°C affords the P-P coupled phosphazene Ph2P-N=PPh2-PPh2=N-PPh2 (2) as an oxidation product and, as a reduction equivalent, the novel lead(1+) complex [(Pb1+)2(μ-Ph2P···N···PPh2-)2](Pb-Pb) (3). The crystal structure determination of the red compound 3 shows a Pb-Pb bond length of 304.1(1) pm. The 31P- and 207Pb-NMR spectra of 3 are complicated due to the presence of a higher order spin system (AA′A′′A′′′X for the mono-207Pb isotopomer, AA′A′′A′′′XX′ for the bis-207Pb isotopomer). Simulations of the 31P and 207Pb spectra both on material with natural isotope abundance and on the 207Pb-labelled compound (3*) reveal a large Pb,Pb coupling constant of 7708 Hz, indicative of a covalent Pb-Pb bond. - Though InCl3 is diagonally related to PbCl2, no significant redox process is observed in the reaction between InCl3 and 1. The yellow crystals of [In3+(Ph2P···N···PPh2-)3] (4) that are obtained were also investigated by X-ray analysis. These show a propeller-like configuration of the three four-membered chelate rings with indium(3+) as the centre.
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  • 9
    Electronic Resource
    Electronic Resource
    Synthesis, Structure, and Properties of Osmium Complexes Containing [Os(′S4′)] and [Os(′S2′)2] Fragments (′S4′2- = 1,2-Bis(2-mercaptophenylthio)ethane(2-), ′S2′2- = 1,2-Benzenedithiolate) (1998)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 819-826 
    Details
    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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  • 10
    Electronic Resource
    Electronic Resource
    Solution-Dimerization of 4-Aryl-1,4-dihydropyridines (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 245-249 
    Details
    ISSN: 1434-193X
    Keywords: Cycloadditions ; Cage compounds ; Dimerizations ; Steric hindrance ; Photochemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---On irradiation at λ ≥ 270 nm solutions of 4-aryl-1,4-dihydropyridines 1 yield cage dimers 2 as the main products beside small amounts of anti dimers 3. 1H-NMR data and X-ray crystal structure prove centrosymmetrical properties for both dimers with axially orientated 4-aryl substituents. Irradiation with filtered light (λ 〉 313 nm) leads to syn and anti dimers 4 and 3 in nearly equal yields. The poor yields of anti dimers 3 on irradiation with unfiltered light are demonstrated to result from a partial cleavage back to their monomeric starting materials 1.
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