bluuebunny/crossref_metadata_2025 huggingface dataset:
Das reaktive Verhalten von phenyl-und imidazolylsubstituierten Propenoyldiphenylphosphanen / The Reactive Behaviour of Phenyl and Imidazolyl Substituted Propenoyldiphenylphosphanes
Authors: Lindner Ekkehard , Tamoutsidis Efstathios
Published: February 2015

The unsaturated acylphosphanes RC(O)PPh2 (4a, b') [R = Ph-CH = CH (a), C3H4N2(Cl)-C(Ph) = CH (b')] are obtained by reaction of RC(O)Cl (3a, b') with (CH3)3SiPPh2. The preparation of 3b' is possible by addition of imidazole to the triple bond of Ph-C=C-C(O)OC2H5 and subsequent hydrolysis of RC(O)OC2H5 (lb) [R = C3H3N2-C(Ph) = CH (b)] and chlorination of RCO2H (2b'). From 4a and imidazole the imidazolide Ph2P(Ph)CH-CH2-C(O)-N2C3H3 (5) is formed which can be oxidized to give Ph2(O)P(Ph)CH-CH2-C(O)-N2C3H3 (6). 4a is coordinated in two different ways to transition metals. A 1:1 molar ratio of 4 a and LnMnTHF [LnMn = (η5-C5H5)Mn(CO)2] yields the P-coordinated complex RC(O)P(Ph2)-MnLn (7a). Excess of LnMn·THF results in the formation of P- and η2-coordinated LnMn-P(Ph2)C(O)(η2-C2H2Ph)MnLn (8a). In the presence of HP(O)Ph2, 4a is oxidized with molecular oxygen to give the phosphorylated alcohol RC[P(O)Ph2]2OH (9a). Via the oxide 10 a and the enol ether Ph2(O)P-CHPh-CH = C(OCH3)P(O)Ph2 (11a) the ester Ph2(O)P-CHPh-CH = C[OC(O)R]P(O)Ph2 (12 a) can be isolated from the Arbusov reaction of 3a and CH3OPPh2.
Activated Nitriles in Heterocyclic Syntheses, I Novel Synthesis of Pyrrolones and 1,2,4-Triazol-3-oyl nitriles
Authors: Elmoghayar Mohamed Rifaat Hamza , Ibrahim Mohamed Kamal Ahmed , Ramiz Mahmoud Mohamed Mahfouz , Elnagdi Mohamed Hilmy
Published: February 2015

Heterocyclic Synthesis, Pyrrolones The behaviour of 4-benzylidene-2-oxazolin-5-one (2) and of 4-phenylazo-2-oxazolin-5-one (3) toward a variety of active methylene reagents is reported. Cleavage of the oxazolin-5-one ring was observed in most cases. A variety of new, otherwise, difficult accessible, azolyl derivatives could be prepared.
Zum Cycloreversionsmechanismus von 3.3-Bis(trifluormethyl)-2.2-dihydro-1.4.2-oxazaphosphol-4-enen [1] / Cycloreversion Mechanism of 3,3-Bis(trifluoromethyl)-2,2-dihydro-l,4,2- oxazaphosphol-4-enes [1]
Authors: Burger Klaus , Tremmel Stephan , Trost Gabriele , Simmerl Reinhold , Hübl Dieter
Published: February 2015

2,2,2-Trimethoxy-3,3-bis(trifluoromethyl)-2,2-dihydro-1,4,2-oxazaphosphol-4-enes on thermolysis undergo a 1,3-dipolar cycloreversion reaction with formation of bis(trifluoro-methyl) substituted nitrile ylides. Trapping reactions of the 1,3-dipolar species with α,β-unsaturated carboxylic acid esters and nitriles are described. 2-Aryl-3-carbethoxy-5,5-bis(trifluoromethyl)-1-pyrrolines obtained undergo an uncatalyzed autoxidation pro-cess to give 2-aryl-3-carbethoxy-3-hydroxy-5,5-bis(trifluoromethyl)-1-pyrrolines. 5,5-Di-fluoro-4-trifluoromethyl-2-oxazolines and 5-fluoro-4-trifluoromethyl-oxazoles formed as by-products indicate that the thermal induced [3+2]-cycloreversion reaction of 2,2,2-tri-methoxy-3,3-bis(trifluoromethyl)-2,2-dihydro-1,4,2-oxazaphosphol-4-enes is most likely a stepwise process.
Activated Nitriles in Heterocyclic Synthesis: The Reaction of Nitriles with Mercapto Acides
Authors: Elgemeie Galal Eldin Hamza , Elfahham Hassan Attia , Hassan Sanna Mohy Eldin , Elnagdi Mohamed Hilmy
Published: February 2015

Several new thiazolo[2,3-a]pyridine derivatives were obtained via the reaction of mercaptocinnamic acid and thioglycollic acid with some activated nitriles and treatment of the resulting 2-thiazolin-4-ones with cinnamonitrile derivatives.
Das Verhalten von Oxalyl-bis ( diphenylposphan ) gegenüber Sauerstoff / The Behaviour of Oxalyl-bis(diphenylphosphane) Towards Oxygen
Authors: Lindner Ekkehard , Kern Herbert
Published: February 2015

Oxidation of Oxalyl-bis(diphenylphosphane), Mechanism In dependence of the solvent, oxalyl-bis-(diphenylphosphane) (1) is oxidized with mole-cular oxygen either in a radical or an ionic mechanism to give -via the radicals· PPh2 and the recombination products [-PPh2]2 (3) -the oxide [Ph2P(O)]2 (4) and [Ph2P(O)]2O (6), respectively. In both cases CO and CO2 are eliminated in nearly equal amounts.
Zur Chemie des Bis(methylsulfonyl)-amins (Dimesylamins), V [1] N-Chlorsulfonyl-methansulfonamid: Ein Produkt der Reaktion von Tetramethylsilan mit Imido-bis(schwefelsäurechlorid) / Investigations on Bis(methylsulphonyl)-amine (Dimesylamine), V [1] N-Chlorosulphonyl-methanesulphonamide: A Reaction Product from Tetramethylsilane and Imido-bis(sulphuryl chloride)
Authors: Blaschette Armand , Seurig Gerlinde
Published: February 2015

Tetramethylsilane reacts with HN(SO2Cl)2 (1) in a complex manner, the nature of the product mixture depending strongly on the reaction conditions. Refluxing 1 with TMS in excess, using CH2Cl2 as a diluent, affords in high yield the new compound HN(SO2Cl)(SO2Me) (2) according to eq. (3). Hydrolysis of the crystal-line, moisture sensitive compound 2 is described by eq. (4).
N-Methylcarbamoylphosphate, I. Synthese / N-Methylcarbamoyl Phosphates, I. Synthesis
Authors: Seel Fritz , Klein Norbert
Published: February 2015

Solutions of mono-and bis-N-methylcarbamoyl phosphates in non-aqueous solvents [e.g. acetonitrile, dimethyl formamide, chloroform) and, surprisingly, even in water are readily obtained by the reaction of methyl isocyanate with the solution of an appropriate mono-or dihydrogenphosphate. The course of the reactions and the limited stability of N-methylcarbamoyl phosphate ions in solutions can be monitored through 31P NMR measurements. Various types of compounds, including a coordination compound of cobalt could be isolated in crystalline form: [Et3NH]HX, KHX, NH4HX, Na2X · H2O, MgX · 4 H2O, CaX · H20, SrX · 2 H2O, BaX · H2O, ZnX · 5 H2O, CdX · 2 H2O, [(NH3)5CoX]ClO4, [Et3NH]Y, AgY · MeCN, X = MeNHC(O)OPO3, Y = [MeNHC(O)O]2PO2.
Bildung von Amidophosphaten und Amidophosphorsäure aus N-Methylcarbamoylphosphaten / Formation of Amidophosphates and Amidophosphoric Acid from N-Methylcarbamoyl Phosphates
Authors: Seel Fritz , Klein N.
Published: February 2015

The synthesis of various amidophosphates can be readily accomplished in aqueous solutions by the reaction of amines with solutions of sodium, potassium or ammonium N-methylcarbamoyl phosphate, prepared by the reaction of methylisocyanate with the corresponding hydrogen phosphates. Procedures for the synthesis of NH4[O3PNH3] and Ca[O3PNH2CH3]2 · 4 H2O are described in detail.
Synthese und Struktur von N2S3Cl+SbCI6 - / Synthesis and Structure of N2S3Cl+ SbCl6-
Authors: Isenberg Wilhelm , Homsy Nayla K. , Anhaus Jens , Roesky Herbert W. , Sheldrick George M.
Published: February 2015

N2S3Cl+ SbCl6- was prepared by chlorination of N4S4 · SbCls5 with elemental chlorine. The crystals are monoclinic, P21/c, with a = 1492.4(4), b = 1233.6(2), c = 1437.5(4) pm, β = 91.40(2)°, and R = 0.059 for 3663 observed reflections. There are two independent cations and anions in the asymmetric symmetric unit. The appreciable interionic interaction results in a high density of ρ = 2.642 g · cm -3 (calcd).
31P−15N Coupling Constants and 15N/14N Isotope Effects on 31P NMR Chemical Shifts of 2-Phenylamino-2-oxo(-thioxo, -selenoxo)- 4-methyl-1,3,2-dioxaphosphorinanes and Related Compounds
Authors: Gombler Willy , Kinas Ryszard W. , Stec Wojciech J.
Published: February 2015

The strong influence of a chalcogen atom (O, S, Se) attached to phosphorus on the spin-spin coupling constant 1J(P-15N) in the family of diastereoisomeric 2-|15N] -phenyl-amino-2X(X = O, S, Se)-4-methyl-l,3,2-dioxaphosphorinanes is demonstrated. The 15N/14N isotope effect on the nuclear shielding of phosphorus-31 is larger for the shorter equatorial than for the longer axial P-N bonds.
Thermoanalytische, IR-spektroskopische und quantenchemische Untersuchungen an Kristallmodifikationen des Trichlorphons / Thermo-analytical, IR-spectroscopical and Quantum-chemical Investigations on Crystal Modifications of Trichlorphone
Authors: Sohr Hans , Hanschmann Günter , Utschik Hermann
Published: February 2015

Several modifications of trichlorphone can be prepared by recrystallizing the raw substance from various solvents under special conditions. One of these modifications is obviously an optical isomer. The different thermo-analytical behavior of the modifications is probably due to the relative content of distinct dimer species. This interpretation is supported by quantum-chemical calculations and by analysis of infrared spectra.
Coordinative Interactions in Chelated Complexes of Silicon, Part III Crystal and Molecular Structure of 1-Trichlorosilyl-1,2,3,4-tetrahydro-1,10-phenanthroline
Authors: Klebe Gerhard , Bats Jan W. , Hensen Karl
Published: February 2015

The crystal structure of C12H11N2SiCl3 (monoclinic, P21/m, Z = 2, with a: 9.284(4), b: 7.226(2), c: 10.832(5) Å, β = 115.14(3)°) was refined to R(F) =0.035 from 1228 independent reflections. A trigonal bipyramidal, pentacoordinate silicon is observed. The chelated complex shows two different Si−N bonds, a coordinative bond (1.984(2) Å) between Si and N on the axial position and a Si−N single bond (1.737(3) A, equatorial plane), introduced by chemical reaction. The coordinative bond is 14.2% longer than the Si−N single bond. The lengthening of the coordinative bond in the present case is compared with distances in other extracoordinated silicon compounds.
Optisch aktive Übergangsmetall-Komplexe, 84 [1] Substituenten-Effekte in Diastereomerengleichgewichten von quadratisch-pyramidalen Mo-Komplexen / Optically Active Transition Metal Complexes, 84 [1] Substituent Effects in Diastereomer Equilibria of Square-Pyramidal Mo Complexes
Authors: Brunner Henri , Schönhammer Beate
Published: February 2015

Amidinato complexes

with sub­stituents R at the cyclopentadienyl and R′ in the p-position of the phenyl at the asym­metric C atom were synthesized and characterized. The diastereomers differing in their 1H NMR spectra were partly separated by fractional crystallization. After equilibration with respect to the labile Mo configuration the diastereomer ratio, a measure for the asymmetric induction from the chiral ligand on the formation of the two Mo configura­tions at equilibrium, was determined by 1H NMR integration. The diastereomer ratio decreases for substituents R′ = F and R = CH3, and increases for R' = OCH3, com­pared to the unsubstituted compound.
Reaktionen des Hexaphenylcarbodiphosphorans, IV [1] Reaktionen des Hexaphenylcarbodiphosphorans mit Halogenverbindungen. Diphosphaallylkationen / Reactions of Hexaphenylcarbodiphosphorane, IV [1] Reactions of Hexaphenylcarbodiphosphorane with Halogen Compounds. Diphosphaallyl Cations
Authors: Bestmann Hans Jürgen , Oechsner Helmut
Published: February 2015

Hexaphenylcarbodiphosphorane (1) undergoes nucleophilic displacement reaction with halogen compounds 3 with formation of compounds 5 which can be regarded as salts of the diphosphaallylcation. 1 reacts with bromoacetic ester 11 as base, with proton abstraction and formation of a carbanion 12 which gives rise to formation of (E)-cyclopropan-tricarboxylicacid ester (13). In an analogous way, 1 attacks isothiocyanatoaceticacid ester (14) with formation of an ionpair 15 which undergoes a cycloaddition with a second molecule 14 forming 16, which can be converted into the mercaptothiazol derivative 17 by treatment with HCl.
Zur Synthese von substituierten Phenazinen aus Benzofurazanoxid und Hydrochinonen [1] / Synthesis of Substituted Phenazines from Benzofurazanoxid and Hydroquinones [1]
Authors: Römer A. , Sammet M.
Published: February 2015

The sterical course of the formation of substituted phenazines from benzofurazanoxid and hydroquinone derivatives was investigated. The additional functional group of the hydroquinone determines the substitution pattern and the product ratio of the phenazines formed.
In the Search for New Anticancer Drugs, III+ Phosphorylated Diaziridine Derivatives
Authors: Sosnovsky George , Lukszo Jan
Published: February 2015

Several N-diethoxyphosphoryl derivatives 7 of various diaziridines, and compounds 12, 15a, 15b, 18 and 20, structurally related to TEPA (1a) and spin labeled Thio-TEPA (1c) were synthesized.
Heterocyelische Siebenring-Verbindungen, XXVI [1] Darstellung und photochemische Reaktion einiger substituierter 4-Phenyl-l-benzoxepine / Heterocyclic Seven-membered Ring Compounds, XXVI [1] Synthesis and Photochemical Reaction of Several 4-Phenyl-1-benzoxepins
Authors: Hofmann Hans , Heidrich Rainer , Seubert Andreas
Published: February 2015

The 4-phenyl-l-benzoxepins 4, 5 and 8 have been prepared from the seven-membered diketone 1 by enol-alkylation or -acylation reactions; their photoreaction yields the corresponding 1-phenyl-2a,7 b-dihydrocyclobuta[b] l-benzofurans 9, 10 and 11.
Die Kristallstrukturell von CaHg(SCN)4 · nH2O (n = 2,3). Verwandtschaftsbeziehungen zwischen den Verbindungsklassen der Tetrathiocyanatomercurate(II) von Erdalkaliionen und 3d-Metallionen / The Crystal Structures of CaHg(SCN)4 · nH2O (n = 2, 3). Relations between Tetrathiocyanatomercurates(II) of the Alkaline-Earth-Ions and Ions of the 3d-Type
Authors: Brodersen Klaus , Hummel Hans-U.
Published: February 2015

CaHg(SCN)4 · nH2O (n = 2(1), n = 3(2)) were isolated from an aqueous solution of Ca(NCS)2 · 4H2O and Hg(SCN)2· 1 is compared with the analogous MgHg(SCN)4 · 2H2O by means of powder patterns. The crystal structure of 2 has been determined. 2 is monoclinic, space group P21/c with a =9.469(4), b = 22.781(5), c = 6.587(4) Å, β = 93.6(3)°, Z = 4, dc = 2.46 g · cm-3.

The structure was refined to R = 7.42 and Rw = 4.96% for 1224 independent reflec­tions.

The species MHg(SCN)4 · 2H2O (M = Mg, Ca, Ni) contain nearly tetrahedral Hg(SCN)4 and octahedral M(OH2)2(NCS)4 groups which are joined by Hg-SCN-M bridges.

In contrast the structures of the other compounds MHg(SCN)4 · nH2O (M = Co, n = 0; M = Ca, Sr, n = 3) are based on the diamond net. There is tetrahedral coordination of all the metal atoms, M having 4 N and Hg 4 S nearest neighbours. In the hydrates the H2O molecules are situated additionally at the Ca and Sr atoms [*].
Darstellung und spektroskopische Charakterisierung von Hexaisothiocyanatoruthenat(III) / Preparation and Spectroscopic Characterisation of Hexaisothiocyanatoruthenate(III)
Authors: Fricke H.-H. , Preetz W.
Published: February 2015

The reaction of RuCl3 · 3 H2O with aqueous KSCN does not yield [Ru(NCS)e]3- as supposed previously, but a mixture of bond isomeric complexes [Ru(NCS)n(SCN)6-n]3-, n= 1-4. On prolonged heating of the solid tetrabutylammonium(TBA)-salts of this mixture (TBA)3[Ru(NCS)5(SCN)] is formed, which decomposes above 130 °C. By an­nealing the more stable bis-triphenylphosphineiminium(PNP) salts up to 160 °C the complex mixture is rearranged to (PNP)3[Ru(NCS)6]- On stirring the emulsion of the (PNP) compound in ethanol with a 100-fold excess of (TBA)Br, (TBA)3[Ru(NCS)6] is obtained. The IR and Raman spectra are assigned according to the point symmetry Oh of the complex ion.
Über das o-Natriumtelhirostannat(rV) Na4SnTe4 / On the o-Sodium-tellurostannate(IV), Na4SnTe4
Authors: Eisenmann Brigitte , Schäfer Herbert , Schrod Heike
Published: February 2015

The new compound Na4SnTe4 crystallizes in the orthorhombic system, space group P212121 with lattice constants a = 865.8(5) pm, b = 884.0(5) pm, and c = 1526.9(8) pm. In the structure there are isolated SnTe4
4- -tetrahedra.
Komplexbildung und Ligandenfluktuation im System Co (II) / [18] Krone-6 / Complex Formation and Ligand Fluctuation in the System Co(II)/[18]crown-6
Authors: Dickert Franz L. , Gumbrecht Walter
Published: February 2015

The ligand properties of [18]crown-6 towards Co(II) ions were studied by 1H and 13C NMR spectroscopy in nitromethane and nitromethane/methanol. The complexes [Co([18]crown-6)]++ and mer-[Co([18]crown-6)(CH3OH)3]++ which were detected in solu­tion show ligand fluctuations on the NMR time scale. For the mixed complex a crown ether rotation occurs. Additionally, a synchronous process between the movement of the macrocyclic ligand and the dissociation reaction of methanol from the metal ion is observed.
Oxidation of 4-Lithium-diazasilacyclopentene with Transition Metal Halides / Oxidation of 4-Lithium-diazasilacyclopentene with Transition Metal Halides
Authors: Hesse Michael , Klingebiel Uwe
Published: February 2015

4-Lithium-3,3,5-trimethyl-2-tert-butyl-1,2-diaza-3-sila-5-cyclopentene is oxidized in the reaction with transition metal halides and subsequently dimerizes. Oxidation potentials are given and a reaction mechanism is proposed.
Beiträge zur Chemie des Phosphors, 132 [1]. 31P-Kernresonanzspektrum und Struktur von Trimethylheptaphosphan(3), P7Me3 / Contributions to the Chemistry of Phosphorus, 132 [1]. 31P NMR Spectrum and Structure of Trimethylheptaphosphane(3), P7Me3
Authors: Bäudler Marianne , Pontzen Thomas
Published: February 2015

Trimethylheptaphosphane(3) (1) was proved to possess the earlier reported structure of a 3,5,7-triorganotrieyclo[2.2.1.02,6] heptaphosphane [3] by complete analysis of its 31P{1H} NMR spectrum. The experimental spectrum can be simulated very satisfactorily by the superposition of the spectra of two isomers P7Me3sym and P7Me3 asym, differing from each other in the orientation of the methyl groups. A comparison of the chemical shifts with those of (Me3Si)3P7 and Li3P7 leads to a detailed information about the geometry of the P7-skeleton in both isomers of 1.
A Novel Ring Closure to Furo[2,3-b]quinoxaline [1, 2]
Authors: Amer Adel , Ventura Montserrat , Zimmer Hans
Published: February 2015

An efficient method for the synthesis of furo[2,3-b]quinoxalines has been devised. Thus, 3-halo-2-arylfuro[2,3-b]quinoxalines, 5a-5c were synthesized by the action of cone. H2SO4 on 3-(1-halo-2-oxo-2-arylethyl)-2(1H)quinoxalinones, 3b, 3c and 3f respectively. When 3-(1-halo-2-oxo-2-substitutedethyl)-2(1H)quinoxalinones 3d and 3e (substituent = t-butyl, ethoxy) were utilized in this reaction 3-halomethylene-2(1H)quinoxalinone 6a and 6b were obtained in high yield.
Synthesis of Some N-Alkylamino-N-vanillylpropionamides
Authors: Baldessari Alicia , Gros Eduardo G.
Published: February 2015

Following a general method N,N-dimethyl, N,N-diethyl, N-isopropyl and N-piperidinyl- amino-N-vanillylpropionamide were synthesized. Their spectroscopic (1H and 13C NMR, MS) properties are reported.
Notizen: Die Hydrolyse von TeF6 / The Hydrolysis of TeF6
Authors: Tötsch Walter , Sladky Fritz
Published: February 2015

The stereochemistry of the hydrolysis of tellurium hexafluoride has been followed up by 125Te NMR spectroscopy for each individual step of replacement of fluorine by a hydroxy group.
Notizen: Polarographie Reduction of 1,1′-Dimethyl-4,4′-oxybispyridinediiuni Bis(fluorosulfonate)
Authors: Rockley Jean E. , Summers Lindsay A.
Published: February 2015

The diquaternary salt of 4,4′-oxybispyridine, 1,1′-dimethyl-4,4′-oxybispyridinediium bis- (fluorosulfonate), is reduced polarographically by a one electron transfer not involving hydro­gen to an unstable radical cation at a potential (E0) of -0.80 V in the pH range 5.1-10.4.
AB2X2 -Verbindungen mit CaAl2Si2-Struktur, IX [1] / AB2X2 Compounds with the CaAl2Si2 Structure, IX [1]
Authors: Mahan Ali , Mewis Albrecht
Published: February 2015

The compounds ZrCu2P2, YZnCuP2, LaZnCuP2, and CeZnCuP2 have been prepared and their structures have been determined. They are isotypic and crystallize trigonally in the CaAl2Si2-type structure (space group P3̄̄m 1) with the lattice constants:

ZrCu2P2 a = 381,2(1) pm, c = 617,1(2) pm,

YZnCuP2 a = 398,3(1) pm, c = 652,3(2) pm,

LaZnCuP2 a = 408,2(1) pm, c = 674,2(2) pm,

CeZnCuP2 a = 406,4(1) pm, c = 669,7(2) pm.

The compounds ALiCu2P(A=Y, Ce, Sm, Tb, Yb) crystalizze trigonally, too, in a very similar structure with the following lattice constants:

YLiCuP2 a = 398,5(1) pm, c = 657,0(2) pm,

CeLiCu2P2 a = 404,2 (1) pm, c = 671,8 (2) pm,

SmLiCu2P2 a=401,4 (1) pm, c = 663,4 (2) pm,

TbLiCu2P2 a = 399,4 (1) pm, c = 656,3 (2) pm,

YbLiCu2P2 a = 396,0 (1) pm, c = 648,4 (2) pm.
Oxidative Addition of Pseudohalogen to [P(OPh)3]4Ni
Authors: Bobadilla M. , Morán M.
Published: February 2015

The title compound reacts with cyanogen halides, XCN (X = Br or I) to give the complexes L2(X)(CN)Ni (L = P(OPh)3, X = Br or I). The oxidative addition of (SCN)2 and (SeCN)2 to the same compound results in the formation of L2Ni(XCN)2 (X = S or Se).

All the complexes have been characterized by elemental analysis, and IR, 1H NMR and electronic spectra.
The Molecular Structure of Selenium Dichloride, SeCl2, Determined by Gas Electron Diffraction
Authors: Fernholt Liv , Haaland Arne , Seip Ragnhild , Kniep Rüdiger , Korte Lutz
Published: February 2015

The electron diffraction pattern of the vapor from a sample of SeCl4 has been recorded with a reservoir and nozzle temperature of about 175 °C. The gas jet was found to consist of SeCl2 (80%) and Cl2 (20%). The bond distance in SeCl2 is ra(Se-Cl) = 2.157(3) Å, the valence angle <ClSeCl = 99.6(5)°.
Metallkomplexe mit biologisch wichtigen Liganden, XXVII [1] Palladium(II)-und Platin(II)-Komplexe mit Aminomonosacchariden / Metal Complexes with Biological Important Ligands, XXVII [1] Palladium(II) and Platinum(II) Complexes with Aminomonosaccharides
Authors: Thiel Gerhard , Beck Wolfgang
Published: February 2015

A series of dihalo palladium and platinum complexes X2PtL2 (X = Cl, I) with aminosugars L = 2-amino-2-deoxy-1,3,4,6-tetra-O-acetyl-β-D-glucopyranose, 1-O-methyl-2-amino-2-deoxy-4,6-O-benzyliden-a,β-D-glucopyranoside, 1-O-methyl-2-amino-2-deoxya-α,β-D-glucopyranoside, 6-amino-6-deoxy-1,2:3,4-di -O-isopropyliden-a-D-galactopyranose has been prepared and characterized by their IR, 1H and 13C NMR spectra. Monosaccharides and aminomonosaccharides have been attached to the complex via the carboxy group of α-amino acid PtII complexes to give esters or amides with the monosaccharides as the alcohol or amine components, respectively.
Azaborolinyl-Komplexe, XII [1] Gemischte η4 -1.2-Azaborolin-η5-cyclopentadienyl- und η5-1.2-Azaborolinyl-η5-cyclopentadienyl-Cobalt-Sandwich-Komplexe / Azaborolinyl Complexes, XII [1] Mixed η4-1,2-Azaboroline-η5-cyclopentadienyl-, and η5 -1,2-Azaborolinyl-η5-cyclopentadienyl Cobalt Sandwich Complexes
Authors: Schmid Günter , Höhner Uwe , Kampmann Detlef
Published: February 2015

Neutral 1-tert-butyl-2-methyl-Δ3-1,2-azaboroline and 2-methyl-1-trimethylsilyl-Δ3-1,2- azaboroline act as 4π electron donors in the mixed sandwich complexes 1-tert-butyl-2-methyl-η4-1,2-azaboroline-η5-cyclopentadienyl cobalt (1) and 2-methyl-1-trimethylsilyl-η4-1,2-azaboroline-η5-cyclopentadienyl cobalt (2), respectively. They are formed by the reaction of (C5H5)Co(C2H4)2 with the free ligands without any solvent and are isolated as green oily liquids. 1 and 2 can be transformed into mixed sandwich complexes with η5-1,2- azaborolinyl ring ligands by loss of a hydrogen atom of the CH2 group. This occurs at room temperature to give 1-tert-butyl-2-methyl-η5-1,2-azaborolinyl-η5-cyclopentadienyl cobalt (3) and 2-methyl-1-trimethylsilyl-η5-1,2-azaborolmyl-η5-cyclopentadienyl cobalt (4) in low yields. Mass, 1H, and 11B NMR spectra are discussed.
An Energy Rich Phosphate from 2 -Methylimidazole through Nonenzymatic Photophosphorylation * ‘ * * *
Authors: Saygin Omer , Decker Peter
Published: February 2015

Sensitized photooxidation of imidazoles in aqueous solution and in the presence of inorganic phosphate afforded organic phosphates with yields up to 30%. The major phosphorylated product of oxidation of 2-methylimidazole was isolated and identified as the monophosphate of 4,5-dihydroxy-2-methylimidazoline with pKa values of 2.0, 5.2, and 9.8. The compound is energy rich in aqueous solution and hydrolyses in alkaline or neutral solutions irreversibly (ΔHhyd = -9.8 kcal/mole). For the hydrolysis at pH 7 an activation-enthalpy of 25 kcal/mole and -entropy of 8 cal/deg.mole was observed. Be2+ ions catalyse the hydrolysis.
Olefin-, Aromaten-und Allylkomplexe des Vanadiums aus Vanadocen [1] / Olefine, Arene, and Allyl Complexes of Vanadium from Vanadocene [1]
Authors: Jonas Klaus , Wiskamp Volker
Published: February 2015

Vanadocene (Cp2V) was reduced with potassium metal in tetrahydrofuran (THF) to give a 1:1 adduct K[Cp2V] which has been isolated as [K(THF)(Et2O)][Cp2V]. The reactions of this compound with various molecules (L) capable of functioning as ligands were investigated. They cause the liberation of KCp and the formation of several new organovanadium compounds. The products of these reactions were: [K(THF)2.5][CpVC8H12] for L = butadiene (C4H6), [K(THF)1.5][CpVC6H5P(C6H5)2] for L = P(C6H5)3, CpV(C4H6)P(CH3)3 for L = mixture of C4H6 and P(CH3)3. Vanadocene was reacted with allyllithium to yield LiCp and [LiTMEDA][CpV(C3H5)2] (TMEDA = (CH3)2NCH2CH2N(CH3)2), which was transformed via allylbromide to CpV(C3H5)2. Structures and reactivities of these new organovanadium complexes are discussed.
Theoretical Study of the Orientation Dependence of Charge-Transfer Excitations in Quinhydrones
Authors: Vogler Helmut
Published: February 2015

The two longest wavelength electronic transitions of the quinhydrones 1 and the dependence of transition energies and intensities on the mutual orientation of hydro-quinone and p-benzoquinone is studied within semiempirical π-theory. The results are in good agreement with the experimental UV-VIS spectra of closely related cyclophane-quinhydrones. The study is extended to the yet unknown quadruple-layered systems 2 which consist of two quinhydrone moieties.
Übergangsmetallketen -Verbindungen, XVII [1]Darstellung eines anionischen η2 -Ketenylkomplexes / Compounds of Transition Metal Ketenes, XVII [1]Synthesis of an Anionic η2 -Ketenyl Complex
Authors: Sieber Werner J. , Eberl Karl , Wolfgruber Mathias , Kreißl Fritz R.
Published: February 2015

The η2-ketenyl compound

reacts with tetrabutylammonium cyanide forming an anionic η2 -ketenyl complex.
Chemie polyfunktioneller Moleküle, 74 [1]. Synthese, Umlagerung und Eigenschaften diphenylphosphinosubstituierter Uracile / Chemistry of Polyfunctional Molecules, 74 [1]. Synthesis, Rearrangement and Properties of Diphenylphosphino Substituted Uracils
Authors: Ellermann Jochen , Demuth Alfons A. M.
Published: February 2015

5-Bromo-uracil (2) with chloro-diphenylphosphine and triethylamine gives 5-bromo-N(1),N(3)-bis(diphenylphosphino)-uracil (3). In moist acetone, 3 is hydrolyzed to 5-bromo-N(1)-diphenylphosphino-uracil (4). 3 reacts with n-butyllithium under rearrangement and, with HCl, under elimination of a PPh2-group, forms C(5)-diphenylphosphino-uracil (7a). Recrystallization of 7 a from ethanol yields the ethanol-1:1-adduct 7b. Heating of 7a in dimethylsulfoxide with D2O yields the N(1),N(3)-dideutero-C(5)-diphenylphosphino-uracil (7c). All compounds were characterized by infrared, Raman, 1H, 31P NMR and mass spectra. 7a shows a very small antitumor activity.
Scalar Second-Kind Relaxation of 27Al, 69Ga and 71Ga Nuclei in Aluminium and Gallium Complexes
Authors: Tarasov V. P. , Privalov V. I. , Kirakosyan G. A. , Buslaev Yu. A.
Published: February 2015

Spin-spin and spin-lattice relaxation times of nuclei 69,71Ga, 27Al, 14N in anions [MClnBr4-n]-and the solvate complexes [M(CH3CN)6]3+, produced from dissolution of MCl3 and MBr3 in the mixture CH3CN + CH3NO2 (M = Ga, Al), are measured in the temperature range from -40 up to + 70 °C. It is shown that nuclear spins of 69,71Ga, 27Al relax in the anionic and cationic complexes by means of the second-kind scalar and quadrupole relaxation mechanisms (due to the relaxation of the nuclei 35,37Cl, 79,81Br, 14N). The complexes [MClnBr4-n]-and [M(CH3CN)6]3+ in the investigated solutions are inert and do not undergo exchange processes in the NMR time scale. The scalar spin coupling constants in [M(CH3CN)6]3+ are determined from the scalar contribution to the relaxation rate of 69,71Ga, 27Al, and the measured relaxation time of 14N in the solvate complex; the results are J(69Ga-14N) = 59 ± 5 Hz, J(71Ga-14N) = 74 ± 6Hz, J(27Al-14N) = 22 ± 2Hz.
Die elektrochemische Reduktion von Benzylidenmalonitrilen / The Electrochemical Reduction of Benzylidenemalononitriles
Authors: Abou-Elenien G. , Buecher B. , Ismail N. , Rieser J. , Wallenfels K.
Published: February 2015

The influence of different substituents on the electrochemical reduction of benzylidene-malononitriles in benzonitrile at platinium electrodes has been investigated using DC-voltametry, cycl. voltametry and coulometry.
γ-Radiolysis of 2′-Deoxycytidine-5′-phosphate in Deoxygenated Aqueous Solutions. OH Radical-Induced Alterations at the Sugar Moiety
Authors: Schuchmann Heinz-Peter , Wagner Rita , Sonntag Clemens von
Published: February 2015

In order to elucidate some aspects of the mechanism of radical-induced strand break formation in DNA, the γ-radiolysis of N2O-saturated aqueous solutions of 2′-deoxycytidine-5′-phosphate has been studied as a model system. At pH 4 it has been observed that upon OH attack at the sugar moiety phosphate (G ≈ 0.6) and cytosine (G = 1) are released and the following cytosine-free sugars are formed: 2,5-dideoxypentos-3,4-diulose, 1 (G = O.22), 2-deoxy-pentos-4-ulose, 2 (G = 0.18), 2-deoxy-pentos-4-ulose-5-phosphate, 3 (G=0.06), 2-deoxypentonic acid-5-phosphate and its lactone, 5 (G ≈ 0.5). Some 2-deoxyribose-5-phosphate, 4 is also formed.

Upon addition of H2O2 (up to 10-2 M) prior to irradiation, G(1) is drastically reduced without giving rise to another cytosine-free product. G(3) increases at the expense of G(2). G (4 + 5) also increase upon H2O2 addition. The formation of these products and the change of their G values as a function of H2O2 concentration are discussed in the light of well-documented radical reactions of carbohydrates and related compounds.

The precursor of 1 has been considered to be the radical at C-3′, that of 2 and 3 the radical at C-4′ and that of 5 the radical at C-1′. Product 4 is thought to arise from a radical-induced destruction of the cytosine moiety. These primary radicals which may undergo rearrangement, or eliminate phosphate, are readily oxidised by H2O2, a reaction which leads to the change of product distribution mentioned above.
Von Braun (BrCN) Reaction on Solasodine
Authors: Siddiqui Salimuzzaman , Siddiqui Bina S. , Faizi Shaheen
Published: February 2015

Solasodine on reaction with BrCN yielded two isomeric cyanamides in a ratio of 3:1, which have been characterised as C-22 configurational isomers, N-cyanosolasodine (22 R, 25 R) IIA and N-cyanosolasodine (22 S, 25 R) II B on the basis of 1H and 13C NMR studies. The same reaction with piperidine, yielded its cyanamide, the 13C NMR of which is also reported.
Derivate des 1.3-Benzdioxols, 50 [1]. Darstellung von 6.7-Dihydroxychromanmethylenethern / Derivatives of 1,3-Benzodioxoles, 50 [1] Preparation of 6,7-Dihydroxy-chromanes Fused to Cyclic Diethers
Authors: Dallacker Franz , Coerver Wim
Published: February 2015

We describe the preparation of alkylsubst. benzodioxoles, -dioxane, -dioxepine and dioxocine 2a-e.

The can be subjected to a Vilsmeyer-formylation, yielding the aldehydes 3 a-e.

Treatment of 3 a-e with performic acid leads to the phenoles 4 a-e in a Baeyer-Villiger-Oxidation. Using Zincchloride as a catalyst the chromanes 5 a-j can be obtained by reaction of 4 a-e with either prenylbromide or phthylbromide.
Synthesis of a Combined Fragment of Interferon, AcHuIFN αA(30-43)-(123-137)-NH2. Interferon May not be a Sychnological Peptide
Authors: Ljungqvist Anders , Folkers Karl
Published: February 2015

AeHuIFN αA(30-43)-( 123-137)-NH2, Ac-Leu-Lys-Asp-Arg-His-Asp-Phe-Gly-Phe-Pro-Gln-Glu-Glu-Phe-Phe-Gln-Arg-Ile-Thr-Leu-Tyr-Leu-Lys-Glu-Lys-Lys-Tyr-Ser-Pro-NH2 was synthesized toward encompassing the “active site” of the interferons. The design of this 29-amino acid peptide was based on considerations of homology between the different interferons and on combining two regions of interferons, and on known and predicted structural features. The peptide was characterized by amino acid analysis, thin layer chromatography in several systems, and by HPLC. As tested, the peptide neither showed antiviral activity nor blocked antiviral activity of interferon, indicating that the active site was not encompassed or that interferon may not be a sychnological peptide.
Synthesis and Antiovulatory Activities in Rats of Analogs of the Luteinizing Hormone Releasing Hormone Having a Moiety of /?-(3-Quinolyl)-D-a-alanine in Positions 3 and 6
Authors: Folkers Karl , Bowers Cyril Y. , Kubiak Teresa , Stepinski Janusz
Published: February 2015

Analogs of the luteinizing hormone releasing hormone (LHRH) having a moiety (D-Qal-) of β-(3-quinolyl)-D-α-alanine were synthesized toward more effective inhibitors of ovulation. [N-Ac-pCl-D-Phe1,2, D-3-Pal3, D-3-Qal6, D-Ala10]-LHRH was the most effective, and had an antiovulatory activity of 40% at 1 μg/rat. D-3-Qal6 was as effective as D-Trp6 in combination with N-Ac-3⊿Pro1, pF-D-Phe2, D-Trp3. D-Arg6 was superior to D-3-Qal6) in combination with N-Ac-pCl-D-Phe1,2, D-Trp3 (or D-3-Pal3), D-Ala10. The introduction of D-3-Qal3, D-His3 and D-Arg3 in comparable analogs caused substantial loss of activities.
Mechanismus der autokatalytischen Primärreaktion bei der Formose-Reaktion / Mechanism of the Autocatalytic Primary Reaction Step in the Formose Reaction
Authors: Harsch Günther , Harsch Monika , Voelter Wolfgang
Published: February 2015

New insights into the autocatalytic primary reaction step of the formose reaction are obtained by using soluble calcium hydroxide bismethylene glycolate complexes for kinetic investigations in homogeneous phase. The reaction kinetics follows between 20% and 80% formaldehyde consumption a nonlinear rate equation. Specific co-catalytic activities are determined for the most important intermediates and end products of the formose reaction. By correlation of the kinetic results with solubility experiments, ultraviolet, 13C NMR spectroscopic measurements and rates of oxidation and acid formation, a mechanism for the autocatalytic primary reaction is given. The main catalytic effects for the formaldehyde activation are caused by calcium enediolate complexes in an autocatalytic cycle and competition with the Cannizzaro and oligomerisation reaction. Further, but less probable mechanisms are also discussed.
Produktverteilung und Mechanismus der Gesamtreaktion der Formose-Reaktion / Product Analysis and Mechanism of the Formose Reaction
Authors: Harsch Günther , Harsch Monika , Bauer Hermann , Voelter Wolfgang
Published: February 2015

By means of liquid chromatographic analysis, UV, 13C NMR and GC-MS spectroscopy it is possible to determine quantitatively the most important intermediate and final products of the formose reaction. As stable main products xylose, glucose and dendroketose, as stable side products ribose, lyxose, arabinose, mannose, dendroaldose, fructose and sorbose are identified. Instable intermediates are glycolaldehyde, glycerolaldehyde, dihydroxiacetone, erythrose, threose and pentuloses. Cannizzaro reaction, oligomerization and the primary formose reaction are catalyzed by a calcium hydroxide bismethylene glycolate complex.
Notizen: Oxidation of Tetraline by Dioxygen. Effect of Fe(acac)3 on the Thermal and Photoinitiated Reactions
Authors: Luňák Stanislav , Vašková Marie , Vepřek-Šiška Josef
Published: February 2015

The photochemical oxidation of tetraline by dioxygen is catalyzed by ferric acetylacetonate (iron(III) 2,4-pentadionate), the reaction rate increasing markedly with temperature. The rate-determining step of the photochemical oxidation is presumably a catalyzed thermal reaction.
Notizen: Ungewöhnliche Umlagerung eines Phosphinliganden in der Koordinationssphäre von Palladium / Unusual Rearrangement of a Phosphine Ligand in the Coordination Sphere of Palladium
Authors: Fenske D. , Christidis A.
Published: February 2015

(η3-Allyl)(η5-cyclopentadienyl)palladium reacts with bis(diphenylphosphino)maleic anhydride to form a complex in which the C5H5 ligand is inserted into a P-C bond of the phosphine ligand. Reaction of this compound with iodine leads to a new type of phosphino ligand. The structure is studied by X-ray crystal structure analysis.
Notizen: p-Tolytelluro-dimethylstiban - ein Molekül mit Tellur-Antimon-Bindung / p-Tolytelluro-dimethylstibane. A Molecule with the Tellurium-Antimony-Bond
Authors: Mont Wolf-Walther du , Severengiz Tevfik , Breunig Hans Joachim
Published: February 2015

Tetramethyldistibane reacts with equimolar amounts of di-p-tolylditelluride to yield quantitatively p-tolyltellurodimethylstibane, the first molecule with a Te-Sb bond. The compound has been characterised by elemental analysis and by NMR and mass spectra.
Notizen: Heterodiamantane aus Phloroglucinen / Heterodiamantanes from Phloroglucinols
Authors: Risch Nikolaus
Published: February 2015

The 1 -azaadamantane 1 is stereoselectively reduced to the trialcohol 2, as shown spectroscopically by 1H NMR 4J(W) coupling and chemically by reaction with trimethoxymethane to the heterodiamantane 4.
Asymmetrische Katalysen, 13 [1]. Chelat-Liganden und ihre Rhodium-Komplexe mit seitlichen Asymmetriezentren und ihre Anwendung in der enantioselektiven Katalyse / Asymmetric Catalyses. 13 [1]. Chelate Ligands and their Rhodium Complexes with Lateral Asymmetrie Centers and their Use in Enantioselective Catalysis
Authors: Brunner Henri , Rahman A. F. M. Mokhlesur
Published: February 2015

The chelate ligands 1-3 with lateral asymmetric centers at the nitrogen atoms were prepared and characterized. In the Rh complexes 4 and 5 the asymmetric centers directly interact with those coordination positions where during enantioselective catalysis pro-chiral substrates are converted into optically active products.

The compounds 4 and 5, as well as the in situ catalysts [Rh(COD)Cl]2/2 were used in the asymmetric hydrogenation of α-N[acetamino]cinnamic acid and in the asymmetric hydrosilylation of acetophenone with diphenylsilane. The low optical inductions obtained result from the catalyst loosing its chiral information during catalysis due to racemization or fragmentation.
Metallkomplexe mit Tetrapyrrol-Liganden, XXXI [1]. Neutrale und anionoide Bisporphinate des Gers und Praseodyms / Metal Complexes with Tetrapyrrole Ligands, XXXI [1]. Neutral and Anionoid Bisporphinates of Cerium and Praeseodymium
Authors: Buchler Johann W. , Kapellmann Heinz-Günter , Knoff Martina , Lay Kiong-Lam , Pfeifer Stefan
Published: February 2015

The preparation of the lanthanoid bisporphinates, bis[meso-tetra(p-tolyl)porphinato]-cerium(IV) [Ce(TTP)2**] and bis[meso-tetra(p-tolyl)porphinato]hydrogenpraseodymium-(III) [PrH(TTP)2] from Ce(acac)3 and Pr(acac)3 in boiling 1,2,4-trichlorobenzene is described. Ce(TTP)2 is a diamagnetic and rather inert CeIV derivative, PrH(TTP)2 is a paramagnetic PrIII complex and may be deprotonated to give the anion [Pr(TTP)2]- which is characterized by conductivity measurements, electrophoresis, and isolation of its tetra(n-butyl)ammonium or tetraphenylarsonium salt. The compounds are identified by UV/VIS, IR, 1H NMR, and mass spectra. The data are consistent with a sandwich-type square antiprismatic array of the two porphinate disks about the CeIV or PrIII ion as found earlier in the bis-phthalocyaninates U(Pc)2 or NdH(Pc)2.
[Aryl(phenyl)selenoketon]pentacarbonyl-Komplexe von Chrom und Wolfram / [Aryl(phenyl)selenoketone]pentacarbonyl Complexes of Chromium and Tungsten
Authors: Fischer Helmut , Zeuner Siegfried
Published: February 2015

[Aryl(phenyl)carbene]pentacarbonyl complexes of chromium and tungsten, (CO)5M[C(p-C6H4R)Ph] (M = Cr, R = H and M = W, R = NMe2, OMe, Me, H, Br, CF3) react with phenylisoselenocyanate or potassium selenocyanate inserting selenium into the metal-carbene bond to give the first η1 -bonded bisarylselenoketone(carbonyl) complexes, (CO)5M[Se = C(p-C6H4R)Ph]. The compounds were characterized by analytical and spectroscopic means.
Zum ambidenten Charakter des Cyanotrihydroborat-Liganden in Uran(IV)-Organylen / On the Ambident Nature of the Cyanotrihydroborate Ligand in Organouranium(IV) Complexes
Authors: Fischer R. Dieter , Yünlü Kenan
Published: February 2015

Both the acceptedly oligomeric complex [(C5H5)3U(μ-NCBH3)]n (1) and its hitherto unknown, appreciably more soluble and volatile homologue, [(CH3C5H4)3U(μ-NCBH3)]n (2), display NIR/VIS spectra typical of trigonal bipyramidal (tbp) metal coordination in the solid state, but of pseudotetrahedral (ψ-Td) coordination e.g. in CH2CI2 and C6H5CH3 solution. The 1H NMR spectra of 2 in these non coordinating solvents can be best explained in terms of temperature dependent equilibria involving the two rapidly interconverting ψ-Td-isomers (CH3C5H4)3U(η3-H3BCN) and (CH3C5H4)3UNCBH3. A reversible colour change: green ⇋ brown at 130-150 °C also suggests the facile rupture of U-H and U-N bonds, respectively, in thermally excited, polycrystalline (2).
Elektrochemische Synthesen, XIX [1]. Eine elektrochemische Synthese von Polythiazyl / Electrochemical Syntheses, XIX [1]. An Electrochemical Synthesis of Polythiazyl
Authors: Fritz Heinz P. , Bruchhaus Rainer
Published: February 2015

A facile synthesis of (chlorinated) polythiazyl by cathodic reduction of (S5N5)(FeCL4] in (Bu4N)[BF4]/CH2Cl2 at low temperatures is reported. The product was characterized by IR and mass spectra, Debeye-Scherrer diagrams and elemental analyses. Potential applications were tested.
Die Addukte von Bis(di-tert-butylphosphino)- und Bis(di-tertJ-butylarsino)schwefeldiimid mit Cyclopentadienyl-hydridometall- Komplexen CpM(CO)3H (M = Cr, Mo, W) / The Adducts of Bis(di-tert-butylphosphino)- and Bis(di-tert-butylarsino) Sulfur Diimides with Cyclopentadienyl Hydridometal Complexes CpM(CO)3H (M = Cr, Mo, W)
Authors: Herberhold Max , Ehrenreich Wolfgang , Guldner Karlheinz , Jellen Wolfgang , Thewalt Ulf , Klein Hans-Peter
Published: February 2015

The new sulfur diimides S(NPBut
2)2 (a) and S(NAsBut
2)2 (b) react with the hydrido- metal complexes CpM(CO)3H (M = Cr (1), Mo (2), and W (3)) to give 1:1 adducts which contain a three-electron acyl-chelate ligand. Only one of the two PBut
2 and AsBut
2 sub­stituents, respectively, becomes coordinated to the metal; the hydrido ligand of the starting complex (CpM(CO)3H (1-3) is transfered to a N atom of the sulfur diimide system. The structures of the adducts (1a-3a and 1b-3b) are discussed on the basis of their infrared and 1H, 13C, and 31P NMR spectra. The X-ray analysis of 3a confirms the presence of a four-membered metallocycle containing W, C(acyl), N, and P.**
Diehloro(η5 -cyclopentadienyl)chrom-Dimer / Dichloro(η5-cyclopentadienyl)chromium Dimer
Authors: Köhler Frank H. , Cao Ren de , Ackermann Klaus , Sedlmair Josef
Published: February 2015

Reaction of chromocene with chloroform yields [Cp2Cr]+[CpCrCl3]- (2) which is trans­formed to trans-[CpCrCl2]2 (3 a) on heating and to a mixture of cis/trans-[CpCrCl2]2 (3 b/a) on standing in chloroform. 2 and 3a/b have been characterized by paramagnetic 1H and 13C NMR yielding the first spectra of the chromocenium cation and the halfsandwich type [CpCrX2L]n-. For comparison, CpCrCl2(pyridine) (4) has been studied; the NMR data of 4 and [CpCrC3]- indicate that both are electronically similar. An X-ray analysis shows one isomer of 3 to be the trans-compound. Its chromium and bridging chlorine atoms consti­tute a square with a metal-metal distance of 336.2 pm. Magnetic exchange is established for 3 a by temperature dependent NMR studies. The X-ray results suggest superexchange to be the dominating mechanism.
Die experimentelle Bestimmung der Elektronendichteverteilung in einem Chrom-Carben- sowie einem Chrom-Carbin-Komplex / The Experimental Determination of the Electronic Deformation Densities in a Chromium Carbene and a Chromium Carbyne Complex
Authors: Krüger C. , Goddard R. , Claus K. H.
Published: February 2015

The electronic deformation densities for pentacarbonylmethylethoxycarbenechromium I and chlorotetracarbonylethylidynechromium II have been experimentally determined using Neutron (for I) and X-ray diffracted intensities measured from single crystals at 100 K. A build up of electron density in all bonds and around each chromium atom is observed. Deformation density maxima are directed along the 3-fold axes of the approx-imately octahedrally coordinated metal atoms and presumably represent occupation of the t2g d-orbital set. The observed electron density distributions indicate that intermole-cular bonding has an important influence on the distribution of electron density in the molecules.
Platin in seiner ungewöhnlichen Oxidationsstufe + III: Diplatin(III)-Komplexe der Modellnukleobase 1-Methyluracil / Platinum in its Unusual Oxidation State + III: Diplatinum(III) Complexes with the Model Nucleobase 1-Methyluracil
Authors: Lippert Bernhard , Schöllhorn Helmut , Thewalt Ulf
Published: February 2015

Oxidation of the head-tail dimer cis-[(NH3)2Pt(1-MeU)]2(NO3)2 (1-MeU = 1-methyl - uracilato anion, C5H5N2O2) with a mixture of nitrous and nitric acid yields three crystalline species,

[(NO2)(NH3)2Pt(C5H5N2O2)2Pt(]SrH3)2(NO2)](NO3)2 · 3 H2O (1),

[(H2O)(NH3)2Pt(C5H5N2O2)2Pt(]SrH3)2(NO2)](NO3)2 · 5 H2O (2) and

[(NO3)(NH3)2Pt(C5H5N2O2)2Pt(]SrH3)2(NO3)](NO3)2 · 4.5 H2O (3).

The crystal structure of 2 has been determined. 2 crystallizes in the triclinic space group P1̄ with cell dimensions a= 11.959(4), b= 11.560(3), c= 11.261(2) Å, α = 89.16(2), β= 104.36(2), γ = 99.61(2)° and Z = 2. The structure was refined to R = 0.056, Rw = 0.061 on 4311 reflections. The Pt-Pt distance within the dinuclear cation of 2 is 2.574(1) Å and cor­responds to a Pt-Pt single bond. The axial ligands are N̲O2 (Ptl) and O̲H2 (Pt2), the equatorial ligands two NH3 groups, N 3 and O4 of 1-MeU for both Pt atoms. The oxidation state of Pt in 2 is +III. 1H NMR and IR spectra of 1, 2, and 3 reveal a close structural similarity of the three compounds.
Komplexbildung von Rhodium mit 6.6-Dimethylfulven / Complex Formation of Rhodium with 6.6-Dimethylfulvene
Authors: Müller Jörn , Stock Rainer , Pickardt Joachim
Published: February 2015

Reaction of [(nbd)RhCl]2 (nbd = nor bornadiene) with CH3Li and 6.6-dimethylfulvene yields (nbd)Rh(2-propenylcyclopentadienyl). (cod)Rh(Cl)P(CH3)3 (cod = 1.5-cyclooctadiene), obtained by cleavage of [(cod)RhCl]2 with P(CH3)3, reacts with 6.6-dimethyl-fulvene and CH3Li or i-C3H7MgBr with substitution of cod by dimeric fulvene ligands the nature of which depends on the alkyl reagent. The new complexes were characterized by NMR spectra and in one case by X-ray diffraction analysis.
Synthese, Struktur und Sb-Mößbauer-Spektren kovalenter und ionischer Tetraorganoantimon(V) -Verbindungen / Synthesis, Structure and Sb-Mößbauer Spectra of Covalent and Ionic Tetraorganoantimony(V) Compounds
Authors: Schmidbaur Hubert , Milewski-Mahrla Beatrix , Wagner Fritz E.
Published: February 2015

Tetramethylstibonium and tetraphenylstibonium oxinate(1, 2) and anthranilate (4, 5) have been prepared from the antimony pentaorganyls and 8-oxy-quinoline or anthranilic acid, respectively. The crystal structure determination of 1 revealed covalent molecules with planar bidentate oxinate as part of a distorted coordination octahedron at antimony. -121Sb-Mößbauer spectra of 1, 2, 4, 5 and of tetramethylstibonium acetylacetonate (3) are also in agreement with covalent structures, but a pentacoordinate environment of Sb is more likely for the anthranilates 4, 5. The spectra of the hydrogendicarboxylates 6-9, however, point to ionic stuctures with, if any, only weak donor interactions of the anions with the stibonium cations.
Ferrocenylen-cobaltocenylenium-hexafluorophosphat [(h5:h5'-C10H8)2FeCo] [PF6], ein gemischtkerniger Komplex vom Bis(fulvalen)dimetall-Typus / Ferrocenylenecobaltocenyleniumhexafluorophosphate [(h5:h5'-C10H8)2FeCo] [PF6], a Mixed Membered Complex of Bisfulvalenedimetal Type
Authors: Schwarzhans Karl E. , Schottenberger Herwig
Published: February 2015

Ferrocenylenecobaltocenylenium-monochloride and ferrocenylenecobaltocenylenium-hexafluorophosphate were prepared under the aspect of influencing the valence averaging phenomena described for homodinuclear metallofulvalenes. Detected paramagnetism of the monocation is assumed to result from such interactions in dibridged rigid metallocenes. The above cation is characterized by IR, CV, MS, electron microprobe and elemental analyses.