0000000000121523
AUTHOR
Hellmut Singer
showing 22 related works from this author
Rhodium(I)‐Komplexe mit Mono‐ und Diolefinen
1966
Diolefinkomplexe [Rh(Diolefin)Cl]2 (Diolefin = Cyclohexadien-(1.3), Hexadien-(1.5), 2.5-Dimethyl-hexadien-(1.5)) und Monoolefinverbindungen [Rh(Olefin)2Cl]2 (Olefin = Cycloocten, Cyclohepten und Norbornen) wurden aus den Kohlenwasserstoffen und RhCl3·xH2O in wasrigem Athanol erhalten und spektroskopisch charakterisiert. — Die Abhangigkeit der Bestandigkeit obiger Rhodiumkomplextypen von der Art des olefinischen Liganden wurde aufgezeigt und eine Parallele zu der Stabilitat bekannter Silberkomplexe gefunden.
Vergleichende dimerisierung der enantiomere von Oct-1-in-3-ol mit chiralen rhodium-phosphan-komplexen
1996
Abstract Three optically active phosphanes ([(S)-2-methylbutyl]3−nP[phenyl]n(n = 0, 1, 2), were tested as ligands in rhodium(I) complexes to form catalysts for the enantioselective dimerisation of (R)- and (S)-oct-1-yn-3-ol. The catalytic reaction provides enantioselectivity for this type of CC bond formation. For reactions at 45–75°C and depending on the P-ligand used the rates vary for both enantiomers from 6:1 to 50:1 in favour of the (S)-octynol.
Thiophen—Mangantricarbonyl-Komplexe
1967
Abstract Cationic thiophenemanganese tricabonyl complexes of the formula [C 4 (CH 3 ) x H 4- x S Mn(CO) 3 ] + have been prepared with 2-methyl-, 3-methyl-, 2,5-dimethyl-, 2,3,5-trimethyl-, tetramethylthiophene, and with thiophene by the reaction of Mn(CO) 5 Cl+AlCl 3 or AlBr 3 with the thiophenes in petrol ether, at 100–110°. The complexions give yellow solutions which are fairly stable. Their IR and some NMR spectra are given and discussed.
Die oligomerisierung endständiger hydroxyacetylene mit rhodiumkomplexkatalysatoren
1982
The substrate and ligand influence on oligomerisation of terminal hydroxyacetylenes catalysed by rhodium complexes has been studied. In this reaction α- and β-hydroxyacetylenes were compared with each other and with an unsubstituted terminal alkyne. The concentration dependant ligand control with Ph3As and Ph3P has been compared and different ligand association behaviour is found, because only with Ph3As as ligand at intermediate concentrations cyclic trimers are selectively formed. Some brief experiments with different p- and o-substituted triphenylarsines show electronic and marked steric influences on the oligomerisation of 3-methylbutyne-1-ol-3.
Der austausch des cyclopentadienylliganden im methylcyclopentadienyl-mangantricarbonyl
1981
Abstract The exchange of the cyclopentadienyl ring in methylcyclopentadienylmanganese(I) tricarbonyl by methy-substituted benzenes in the presence of aluminium halide leads to [arene-Mn(CO) 3 ] + -ions. The reaction conditions have been optimised; in addition to the yield the purity of the complexes has been determined in some detail. After mild decomposition the arenes were analysed by GLC. Pure [arene-Mn(CO) 3 ] + -ions can be isolated with benzene, toluene, m - and o -xylene.
The oligomerisation of phenylacetylenes with rhodium(I) and P ligands as the catalytic system
1991
Abstract The dependence of the oligomerisation of phenylacetylene to cyclotrimers and dimers upon a Rh(I) complex with different P ligands as the catalytic system has been studied. The influence of substituents in the phenyl ring of the substrate has been examined as well. A selective cyclotrimerisation of phenylacetylenes is achieved with [1,5-C6H10RhCl]2 as the catalyst. A decrease of the selectivity appears with very bulky o-substituents or a substitution in the 2,6-position of phenylacetylene. [P]-control maps indicate a mono-association of the ligand accompanied by a reduced activity of the system. The second association of a P ligand results in an inhibition of the cyclotrimerisation …
The dimerization of substituted 3-TMSO-1-alkynes with (φ3P)3RhCl
1987
Abstract 3-Trimethylsilyloxy-1-alkynes were prepared from 3-hyroxy-1-alkynes and dimerized with (φ3P)3RhCl as a catalyst. The influence of a steric effect on the rates of dimerization is demonstrated.
Iron(II) complexes of naphthalenes. X-ray structure of [cyclopentadienyl-iron(II)-η6-octamethylnaphthalene]PF6
1992
Abstract Complex ions [cyclopentadienyl-Fe(methylnaphthalene)]+ with 4 to 8 methyl substituents have been prepared from [CpFe(o-dichlorobenzene)]+ by a photochemical ligand exchange. Complexation shifts have been determined for 1H and 13C resonances of the η6-bonded naphthalenes. The X-ray structure of [CpFe(octamethylnaphthalene)]PF6 0.5 acetone has been determined. Crystals are monoclinic, the space group C2/c with unit-cell dimensions a = 10.689(4), b = 22.391(5), c = 20.550(4)A, β = 93.41(2)°, Z = 8. The structure determination established a distorted molecular geometry of the octamethylnaphthalene that is different from the free arene and its Cr(CO)3 complex.
Die darstellung von [(CH3)3PRu(CO)2Cl2]2 und [(Ch3)3P]2Ru(CO)2Cl2; Eine berichtigung zu: Die alkoholyse des triethylsilans katalysiert von [(Ch3)3P]2…
1984
Abstract The ruthenium(II) complex used as a catalyst in reactions of alcohols and Et 3 SiH proved to be the dimer [(CH 3 ) 3 PRu(CO) 2 Cl 2 ] 2 and not the complex [(CH 3 ) 3 P] 2 Ru(CO) 2 Cl 2 . Both complexes were prepared, characterized and their catalytic properties were compared.
Activité catalytique de dérivés du ruthénium(II) contenant le ligand triméthylyphosphine
1979
Abstract Three ruthenium(II) complexes containing the ligand PMe3,:RuCl2(PMe3)(C6H6) (I), RuCl2(PMe3)4 (II) and RuCl2(CO)2(PMe3)2 (III) were prepared and their catalytic properties investigated. They showed activity as hydrogenation catalysts in the presence of Me2NH · BH3 and alcohol and the activity increased significantly in the order I
Additionskomplexe von Rhodiumcarbonylchlorid und Olefinen
1966
Bei der Umsetzung von Rhodiumcarbonylchlorid, [Rh(CO)2Cl]2, mit konjugierten Diolefinen wurden kristallisierte Additionskomplexe des Typs [Rh(CO)2Cl]2-Dien (Dien = Cyclohexadien-(1.3), 2.3-Dimethyl-butadien-(1.3)) erhalten, die auch im gelosten Zustande, z. B. in Benzol, existenzfahig sind. 1H-KMR- und IR-Untersuchungen zeigten, das der olefinische Ligand als zusatzliches Bruckenglied in strukturell kaum veranderten Rhodiumcarbonyl-chlorid-Molekeln vorliegt.
Die dimerisierung von endständigen α-hydroxyacetylenen mit rhodiumkomplexkatalysatoren
1978
Abstract The dimerisation of monosubstituted α-hydroxyacetylenes, which is catalysed by rhodium complexes, yields 1,4-disubstituted vinylacetylenes. The catalyst has been optimized for 3-methylbut-1-yn-3-ol as the substrate by using different ligands. Kinetic measurements were carried out with the monomers 3-methylbut-1-yn-3-ol, 3-methylpent-1-yn-3-ol and 1-ethynylcyclohexan-1-ol. In addition the rates of the dimerisation have been compared with those for a further series of α-hydroxyacetylenes. The by-products from the reaction of 3-methylbut-1-yn-3-ol with [(C 6 H 5 ) 3 P] 3 RhCl as catalyst were determined and the yields of the products compared with those of but-1-yn-3-ol and prop-1-yn-…
Der austausch des cyclopentadienylliganden im methylcyclopentadienylmangan(I)tricarbonyl. Untersuchungen zur konkurrierenden komplexbildung mit methy…
1981
Abstract Exchange of the cyclopentadienyl ligand in methylcyclopentadienylmanganese(I) tricarbonyl with methyl-substituted benzenes is catalysed by AlCl 3 + HCl and leads to the cations [arene-Mn(CO) 3 ] + . The methylbenzenes isomerize and disproportionate during the reaction. The distribution of the arenes between the solution and the complex ions has been determined. The different complexing abilities of the arenes lead to the proposal of an associative mechanism for the ligand exchange.
Die Cooligomerisierung von butadien mit α-hydroxycarbonsäureestern
1977
Abstract Glycolic acid butyl ester as well as lactic acid ethyl ester react with butadiene in the presence of palladium(II) acetylacetonate and triphenylphosphine as catalyst. The main product is the 2-trans, 7-octadienyl ether of the hydroxy acid ester, which is formed in yields from 65 to 80% at room temperature.
Synthesis and X-ray crystal structure of manganese(II) pyridine-2-thiolate
1997
2:1 complexes of pyridine-2(1H)-thione (LH) with manganese(II) were prepared: (LH)2MnCl2, (LH)2MnBr2 and [L2Mn]n. The polymeric chain structure of [L2Mn]n contains a distorted octahedrally coordinated manganese (MnN2S4) with chelating ligands, the N-atoms are in cis positions and the S-atoms of the pyridine-2-thiolates bridging; crystallographic data for [C10H8MnN2S2]n: space group C2/c (monoclinic), and R1 = 0.0571 for 1326 reflexes with Fo4σ(Fo).
H‐NMR‐Spektroskopische Untersuchungen an 1.3‐disubstituierten Derivaten des 4.5.6.7.8.8‐Hexachlor‐1.3.3a.4.7.7a‐hexahydro‐4.7‐methano‐isobenzofurans
1968
H-NMR-Spektroskopische Untersuchungen an 1.3-disubstituierten Derivaten des 4.5.6.7.8.8-Hexachlor-1.3.3a.4.7.7a-hexahydro-4.7-methano-isobenzofurans (1) ergaben, das die Bandenverschiebungen in den NMR-Spektren dieser Verbindungen in Benzol gegenuber Deutero-chloroform als Losungsmittel (Δ = τC6H6 τCDCl3) Aussagen uber die Stellung der Protonen bzw. der Substitutenten ermoglichen. — Die in 1-Stellung mono- bzw. in 1.3-Stellung disubstituierten Derivate von 1 tragen ihre Substituenten den Wasserstoffatomen an Kohlen-stoff 3a und 7a gleichgerichtet. — In den untersuchten Verbindungen tritt bei Austauschreaktionen der Substituenten keine Isomerisierung ein.
The oligomerisation of 3-hydroxy-1-alkynes with palladium(II) diketonates and phosphorus ligands as the catalytic system
1993
Abstract 3-Methylhex-1-yne-3-ol has been oligomerised by use of Pd(II) acetylacetonate with 31 different phosphorus ligands as catalyst, yielding a dimer (2,4-disubstituted but-1-en-3-yne) and a linear trimer (1,4,6-trisubstituted hexa-1,3-dien-5-yne) as the two main products. By input-output relations a variation of the diketonate and the P ligand, as weil as an alteration of the phosphorus/palladium ratio, has been connected with product ratios as dependent variables. Phosphines produced three association steps up to a cone angle of 170°; the third step representing a stop complex. For the first association the activity of the catalytic system and the portion of the 2,4-dimer increased wi…
Iridium(I)‐Olefinkomplexe
1966
Durch Umsetzung von Na2IrCl6·6H2O mit nicht-konjugierten Diolefinen (Cyclooctadien-(1.5), Norbornadien), mit konjugierten Diolefinen (Cyclohexadien-(1.3), 2.3-Dimethyl-butadien-(1.3)) sowie mit Monoolefinen (Cyclohepten und Cycloocten) wurden Iridium(I)-Olefin-komplexe verschiedener Typen erhalten und chemisch sowie spektroskopisch charakterisiert. Dargestellt wurden die Verbindungen [Ir(1.5-C8H12)Cl]2, [Ir(nor-C7H8)Cl]2, Ir(1.3-C6H8)2Cl, Ir{(CH3)2C4H4}2Cl, Ir(C7H12)3(CO)Cl, Ir(C8H14)3(CO)Cl und [Ir(C8H14)2(CO)Cl]2 sowie einige Triphenylphosphinderivate. — Die Komplexbildung von Iridium und Rhodium mit Olefinen wurde verglichen.
Zum Ligandenaustausch des Ferrocens mit Methyl- und Ethyl-substituierten Naphthalinen
1988
Abstract The replacement of a Cp ligand of ferrocene by each of ten unsymmetrically substituted naphthalenes yields pairs of complex ions [arene-FeCp] + , which have been identified from their 1 H NMR spectra. The influence of the substituent on the ratio of the two isomers, and its temperature dependence implies a complex reaction mechanism involving an η 2 -bound intermediate of the associated naphthalene. The proton resonances of the alkyl groups of the naphthalenes are shifted to lowfield by complexation; this effect decreases with increasing distance from the iron. The resonance shift of the arene protons has a different sign for the complexed (highfield) and the uncomplexed part (lowf…
Ruthen(II)-komplexe mit zweizähnigem cycloheptatrien und benzol
1967
Zusammenfassung Polymere Ru(II)-Komplexe [Ru(C7H8)Cl2]x und [Ru(C6H6)Cl2]x wurden aus RuCl3·xH2O und Cycloheptatrien bzw. 1,3-Cyclohexadien in Athanol erhalten. Das dimere Derivat (Ru(C6H6)[P(C4H9)3]Cl22 wurde ebenfalls isoliert. Die chemischen und spektroskopischen Eigenschaften dieser Verbindungen sprechen fur eine zweizahnige Koordination der π-gebundenen Cycloheptatrien- und Benzol-Liganden.
Die alkoholyse des triethylsilans katalysiert von [(CH3)3P]2Ru(CO)2Cl2
1983
Abstract [(CH 3 ) 3 Pl 2 Ru(CO) 2 Cl 2 is an effective catalyst for the reaction of alcohols with triethylsilane. The rate of this reaction varies with the substituents in the hydroxy compound; it is fastest for short primary alcohols. Even in the presence of groups which can be hydrosilated (CC triple or double bonds, as well as ketones), a hydroxy group reacts preferably and completely with the silane. Kinetic experiments have been performed with the system Et 3 SiH/CH 3 CH(OH)COOEt/Ru complex.
H‐NMR‐Spektroskopische Untersuchungen an 2.3‐disubstituierten Derivaten des Hexachlorbicycloheptens
1968
Der cyclische Selenigsaureester (4), der cyclische Phenylphosphonigsaureester (5) sowie das cyclische Acetaldehydacetal (7) des 1.4.5.6.7.7-Hexachlor-2.3-bis-hydroxymethyl-bicyclo[2.2.1]-heptens-(5) (1) wurden hergestellt, ihre H-NMR-Spektren vermessen und mit denen bekannter analoger Derivate von 1 (2, 3, 8) verglichen. — Die Bandenverschiebungen in den NMR-Spektren dieser Verbindungen bei Benzol gegenuber Deuterochloroform als Losungsmittel (Δ = τC6H6 τCDCl3) erlauben Aussagen uber die Stellung der Protonen in den Molekulen und damit uber deren Konformationen. — Die Konformation des Selenigsaureesters von 1 (4) stimmt mit der des α-Isomeren des Schwefligsaureesters von 1 (α-Endosulfan) ub…