Published by De Gruyter

Volume 38 Issue 5

Issue of Zeitschrift für Naturforschung B

Contents
Journal Overview

Open Access June 2, 2014

Beiträge zur Chemie des Phosphors, 126. Tris(tert-butylphosphino)-phosphan, P(t-BuPH)₃ - ein teilsubstituiertes Derivat von iso-P₄H₆/ Contributions to the Chemistry of Phosphorus, 126. Tris(tert - butylphosphino)phosphane, P(t-BuPH)₃ - a Partially Substituted Derivative of iso-P₄H₆

Marianne Baudler, Jochen Hellmann, Thomas Schmidt

Page range: 537-542

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Abstract

The reaction of tris(bromo-tert-butylphosphino)phosphane, P(t-BuPBr) 3 , with lithium aluminium hydride leads to the title compound P(t-BuPH) 3 (1), which could be isolated in a pure state. 1 is the first partially substituted derivative of iso-tetraphosphane(6), P(PH 2 ) 3 , and was characterized in all details. Because of the chirality of the Z-BuPHgroups, 1 forms two diastereomers with RRS(SSR)- and RRR(SSS)-configuration in a ratio of about 3:1. The conformation of both isomers, which could be deduced from the 31 P NMR parameters, is mainly determined by the steric situation of the molecule.

Open Access June 2, 2014

Barrier to Rotation about Sulfur-Sulfur Bonds in Homocyclic Sulfur Molecules

Ralf Steudel

Page range: 543-545

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Abstract

It is shown that the distances (d) of the 19 longest bonds in 9 homocyclic sulfur rings of type S n (n = 6-20) depend on the torsional angles (τ) which vary between 0° and 140°. The function d = f(τ) is smallest for τ = 90-100° and largest for τ = 0°; the corresponding bond distance variation amounts to 13 pm or 6%. The height of the torsional cis-barrier is estimated from the enthalpy of formation of gaseous S 7 as equal to or smaller than 24 kJ/mol.

Open Access June 2, 2014

Cycloaddition von Schwefelkohlenstoff an die Azidliganden in (Ph₃P)₂Pd(N₃)₂ und [Co(N₃)₄]^2–/ Cycloaddition of Carbon Disulfide to the Azide Ligands of (Ph₃P)₂Pd(N₃)₂ and [Co(N₃)₄]^2-

Wolf Peter Peter, Wolfgang Beck

Page range: 546-548

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Abstract

(Ph 3 P) 2 Pd(N 3 ) 2 reacts with CS 2 by 1,3-dipolar cycloaddition to give the thiatriazoline- 5-thionato complex (Ph 3 P) 2 Pd(N 3 CS 2 ) 2 . From the reaction of [Ph 4 As] 2 [Co(N 3 ) 4 ] with CS 2 , the isotliiocyanato complex [Ph 4 As] 2 [Co(NCS) 4 ] has been isolated, and the intermediate thiatriazoline-5-thionato complex [Ph 4 As] 2 [Co(N 3 CS 2 ) 4 ] could be detected by its electronic spectrum.

Open Access June 2, 2014

Untersuchungen an Polypseudohalogeniden, II. Darstellung und Kristallstruktur des Rubidiumdicyanotriiodids, Rb[I(ICN)₂]/ Studies on the Polypseudohalides, II. Preparation and Crystal Structure of Rb[I(ICN)₂]

Karl-Friedrich Tebbe, Roland Fröhlich

Page range: 549-553

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Abstract

The new compound Rb[I(ICN) 2 ] can be prepared in aqueous solution by simple addition of two mole equivalents of ICN to one formula unit Rbl. The solid is isotypic with Cs[I(ICN) 2 ] and crystallizes in the orthorhombic space group Pmmn with a = 16.246 Å, b = 6.795 Å, c = 4.397 Å and Z = 2. The crystal structure has been solved from diffractometer data and refined to R = 0.035 for 313 observed reflections. The structure may be interpreted as a layer-like package of Rb+ cations and pentahalideanalogous anions [I(ICN 2 ] - . The anionic groups are angular with symmetry mm 2 and φ ( I-I - - I ) = 128.69°, φ(I- - I-C) = 175.5°, φ=(I-C-N) = 177°, d(I - -I) = 3.271 Å, d(I-C) = 2.11 A, d(C-N) = 1.13 A. The cation is surrounded by a distorted cube of iodine atoms with a minimum distance d(Rb-I) = 3.775 Å. Some additional results on the reactions of alkali halides and halogenocyans in different solvents are mentioned and compared with those described elsewhere.

Open Access June 2, 2014

Über neue monocyclische Acyloxyfluoroborane 2.2.6.6-Tetrafluoro-1.4-dialkyl-1.3.5-trioxa-1.6-diboracyclohexene: Darstellung, Molekül- und Kristallstruktur/ New Monocyclic Acyloxyfluoroboranes 2,2,6,6-Tetrafluoro-1,4-dialkyl-1,3,5-trioxa-2,6-diboracyclohexenes: Synthesis, Molecular and Crystal Structure

Herbert Binder, Walter Matheis, Hans-Jörg Deiseroth, Han Fu-Son

Page range: 554-558

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Abstract

Acyloxyfluoroboranes Trimeric alkoxydifluoroboranes (F2BOR)3 (2) react with organic acid anhydrides by substitution of a ring group OR forming monocyclic acyloxyfluoroboranes of the type 2,2,6,6-tetrafluoro-l,4-dialkyl-l,3,5-trioxa-2,6-diboracyclohexene (3). The X-ray crystal structure determination of 3a shows two conformational isomers: two planar and two non-planar six-membered rings are present in the unit cell. The ring conformation is influenced by weak intermolecular H — F interactions.

Open Access June 2, 2014

β-NbBr₅, eine neue Modifikation von Niobpentabromid mit einer eindimensionalen Lagenfehlordnung/ β-NbBr₅, a New Modification of Niobium Pentabromide Having One-Dimensional Stacking Disorder

Ulrich Müller, Paul Klingelhöfer

Page range: 559-561

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Abstract

While trying to react NbBr 5 with sulfur in a closed tube, crystals of the new modification β-NbBr 5 were obtained. Its X-ray diffraction patterns have sharp reflexions and diffuse streaks showing the presence of a one-dimensional disorder. From the sharp reflexions alone, a statistically averaged sub-structure results; it has the space group Ccmm and the lattice constants a 0 = 644, b 0 = 1867 and c 0 = 615 pm. Taking into account the diffuse streaks, the true structure was deduced; its lattice constants are a = 2a 0 , c = Co, b indefinite due to the disorder. β-NbBr 5 is isostructural to tantalum pentaiodide. It consists of layers of (NbBr 5 ) 2 molecules that are stacked with displacement faults in the direction of b. The bromine atoms have a hexagonal close-packing arrangement.

Open Access June 2, 2014

Transition Metal Complexes with Sulfur Ligands, IV. Synthesis and Reactions of Mo (IV) Complexes with the Tetradentate Thioether-thiol Ligand 2,3,8,9-Dibenzo-1,4,7,10-tetrathiadecane

Bharat B. Kaul, D. Sellmann

Page range: 562-567

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Abstract

Synthesis and characterization of non-oxo Mo(IV) complexes with the tetradentate thioether-thiol ligand 2,3,8,9-dibenzo-1,4,7,10-tetrathiadecane(dttd-H 2 ) are reported. MoCl 4 (THF) 2 reacts with dttd-H 2 in THF at room temperature to give the paramagnetic (2.61 BM, 295 K) [Mo(dttd)Cl 2 ]. The chlorine ligands in [Mo(dttd)Cl 2 ] can be substituted by sulfur ligands yielding diamagnetic complexes as [Mo(dttd)(CeH 4 S 2 )], [Mo(dttd)(SC 2 H 4 S)] and [Mo(dttd)(SC 2 H 5 ) 2 ]; with Na 2 S, NaHS or H 2 S, the di-μ-sulfido bridged complex [(dttd)Mo(S) 2 Mo(dttd)] is obtained. The reduction of [Mo(dttd)Cl 2 ] by various reducing agents in the presence of CO or NO yields labile carbonyl and nitrosyl species in solution. In contrast to [Mo(dttd)Cl 2 ], the complexes with MoSe cbromophores showed no reactivity to CO or NO under reducing conditions.

Open Access June 2, 2014

Zur Stereochemie von Diazadien-Metall-Komplexen, V. Molekülstrukturen und CO-Kraftkonstanten nicht-starrer Chrom-, Molybdänund Wolframcarbonylderivate DAD M(CO)₃(CO) (C0 = ¹²CO, ¹³CO, C¹⁸0)/ Stereochemistry of Diazadiene Metal Complexes, V Molecular Structures and CO Force Constants of Non-Rigid Chromium, Molybdenum and Tungsten Carbonyl Derivatives DAD M(CO)₃(CO) (CO = ¹²CO, ¹³CO, C¹⁸O)

Heindirk tom Dieck, Thomas Mack, Karl Peters, Hans-Georg von Schnering

Page range: 568-579

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Abstract

Diazadiene metal tetracarbonyls, DAD M(CO) 4 , (M = Cr, Mo, W; DAD = R-N = CH-CH = NR with aliphatic and aromatic substituents R) show equidistribution of one labelled CO when synthesized from fac-DAD M(CO) 3 (CH 3 CN) as a consequence of intramolecular CO site exchange. The structures of two Mo-complexes (1: R = iso-propyl; 2: R = 2,6-diisopropylphenyl) with DAD's of different bulkiness have been solved by X-ray methods. From the infrared solution spectra, including those of isotopically labelled ( 13 CO, C 18 O) compounds, all of the force constants k 1 , k 2 , k tt , k cc and k cc have been calculated independently. The ratios of interaction force constants deviate sharply from Cotton-Kraihanzel assumptions, perhaps because of the substantial deviation of the iraws-pair of CO groups from linearity (1: 154.5°, 2: 147.9°). The solid state N-Mo, Mo-C and C - O bond lengths are neither in agreement with the generally accepted picture for donor/acceptor influences nor with typical IR data and force constant interpretations. (2 with higher v(CO) and k 1 , k 2 has the longer CO bonds and shorter Mo-C bonds than 1.) The force constant sets have been used to calculate CO frequencies for over 60 labelled compounds with good accuracy (Δv < 2 cm -1 ).

Open Access June 2, 2014

Übergangsmetall-Carben-Komplexe, CXXX. Nucleophile Spaltung der Kohlenstoff-Fluor-Bindung in einem Fluorcarben-Komplex des Mangans/ Transition Metal Carbene Complexes, CXXX. Nucleophilic Cleavage of the Carbon-Fluorine Bond in a Fluorocarbene Complex of Manganese

Ernst Otto Fischer, Jiabi Chen

Page range: 580-581

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Abstract

The reaction of C 5 H 5 (CO) 2 Mn[C(C 6 H 5 )F] with n-C 4 H 9 Li results in cleavage of the C(carbene)-F bond and formation of C 5 H 5 (CO) 2 Mn[C(C 6 H 5 )n-C 4 H 9 ]. In a similar way fluoride can be abstracted by ethanol to yield C 5 H 5 (CO) 2 Mn[C(C 6 H 5 )OC 2 H 5 ].

Open Access June 2, 2014

Übergangsmetall-Carben-Komplexe, CXXXI. Umsetzung von [(CO)₅WCNEt₂]BF₄ mit anionischen Organylverbindungen von Elementen der V. Hauptgruppe/ Transition Metal Carbene Complexes, CXXXI. Reaction of [(CO)sWCNEt₂]BF₄ with Anionic Organyl Compounds of Group V Elements

Ernst Otto Fischer, Rudolf Reitmeier

Page range: 582-586

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Abstract

The cationic carbyne complex [(CO) 5 WCNEt 2 ]BF 4 (1) reacts with potassiumdiphenylamide, KNPh 2 , with nucleophilic addition of the amide anion to give (CO) 5 W[C(NEt 2 )NPh 2 ] (2). The corresponding reactions with KPPh 2 , KPEt 2 , KPMePh, NaSbPh 2 and NaBiPh 2 yield the complex [(CO) 5 W(CNEt 2 )] 2 (3), which is formed by reductive dimerization of two carbyne fragments. In case of KPMePh the carbene complexes (CO) 5 W[C(NEt 2 )PMePh (4) and trans-(MePhPH)(CO) 4 W[C(NEt 2 )PMePh] (5) are also obtained. On warming in solution 5 spontaneously rearranges to the novel cyclic carbene complex (6). Reaction conditions, properties and spectroscopic data of the new compounds are reported.

Open Access June 2, 2014

Übergangsmetall-Carbin-Komplexe, LXXIY. Synthese thermisch stabiler neutraler Carbin-Carbonyl-Komplexe von Chrom, Molybdän und Wolfram mit den zweizähnigen Liganden 2.2′ -Bipyridyl und 1.10-Phenanthrolin/ Transition Metal Carbyne Complexes, LXXIV. Synthesis of Thermostable Neutral Carbyne Carbonyl Complexes of Chromium, Molybdenum, and Tungsten with the Bidentate Ligands 2,2′-Bipyridyl and 1,10-Phenanthroline

Alexander Filippou, Ernst Otto Fischer

Page range: 587-591

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Abstract

Reaction of trans-bromotetracarbonyl(phenylcarbyne)-complexes of chromium, molybdenum and tungsten and trans-bromotetracarbonyl(methylcarbyne) complexes of chromium and tungsten with the bidentate ligands 2,2′-bipyridyl and 1,10-phenanthroline results in the replacement of two carbonyl groups leading to very thermostable carbyne complexes with the general formula Br(CO) 2 LMCR (L: 2,2′-bipy, ophen; M: Cr, Mo, W; R : CH 3 , C 6 H 5 ).

Open Access June 2, 2014

η³-Allylmetall-Schwefel-Komplexe, IV/ η³-Allyl-hydrogensulfidopalladium- und -platin-Komplexe/ η³-Allylmetal-Sulfur Complexes, IV. η³-Allyl-hydrogensulfidopalladium and -platinum Complexes

Borislav Bogdanović, Martin Rubach, Klaus Seevogel

Page range: 592-598

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Abstract

Abstract η 3 -Allyl- or η 3 -methallyl-η 5 -cyclopentadienylpalladium react with hydrogensulfide at - 78 °C with selective cleavage of the cyclopentadienyl group to give the dimeric, thermolabile η 3 -allyl- or η 3 -methallylhydrogensulfidopalladium (2, 2a), which decompose above ≈ - 60 °C to palladiumsulfide and propene or isobutene. The new compounds have been characterised by 1 H NMR, IR and Raman spectroscopy. Similarly, η 3 -allyl- and η 3 - methallylhydrogensulfidoplatinum (6, 6 a) have been prepared from hydrogensulfide and η 3 -allyl- and η 3 -methallyl-?75-cyclopentadienylplatinum, respectively. From bis(??3-allyl)- or bis(?y3-methallyl)palladium and H2S rj3-allyl- or ??3-methallylhydrogensulfidopalladium (2', 2a') have been obtained and their IR spectra and physical properties found to differ from those of 2 or 2a.

Open Access June 2, 2014

η³-Allylmetall-Schwefel-Komplexe, V. Mono- und bimetallische, mehrkernige η³-Allylmetall-Sehwefel-Komplexe des Nickels, Palladiums und Platins/ η³-Allylmetal-Sulfur Complexes, V. Mono- and Bimetallic, Polynuclear η³- Allylmetal-Sulfur Complexes of Nickel, Palladium and Platinum

Borislav Bogdanović, Peter Göttsch, Martin Rubach

Page range: 599-603

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Abstract

η 3 -Allylhydrogensulfidopalladium (6) reacts with bis-(η 3 -allyl)- (4) or η 5 -cyclopentadienyl-η 3 -allyl-palladium (11) with elimination of propene to give the known η 3 -allylpalladium- sulfur-cluster (2). The same method was used to prepare the first bimetallic η 3 -allyl-Ni-Pd-, Ni-Pt- and Pd-Pt-sulfur complexes 12-14 (IR-spectra); their structures are still unknown. The polynuclear η 3 -methally Ipalladium- and -platinum-sulfur complexes 2 a and 3 a, soluble in benzene and toluene, have been prepared from the corresponding bis(η 3 -methallyl)metal compounds and H 2 S. In benzene, 2 a may have a structure in which the four palladium atoms adopt a square planar (2a′) or tetrahedral (2a″) geometry.

Open Access June 2, 2014

η³-Allylmeta]l-Schwefel-Komplexe, VI. Anionische η³-Allylnickel- und -palladium-Schwefel-Cluster/ η³-Allylmetal-Sulfur-Complexes, VI. Anionic η³-Allylnickel- and -palladium-Sulfur-Clusters

Reinhard Benn, Borislav Bogdanović, Peter Göttsch, Martin Rubach

Page range: 604-610

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Abstract

η 3 -Allylhydrogensulfidonickel (2) reacts with n-butyllithium with elimination of lithium sulfide and formation of the ionic η 3 -allylnickel-sulfur-cluster [(η 3 -C 3 H 5 Ni) 3 S 2 ] + [Li(THF) 2 ] - (4). The crystal structure of the analogous THF-TMEDA-adduct (4′) indicates that the nickel and sulfur atoms of the anion adopt a trigonal bipyramidal arrangement, in which the sulfur atoms are at the apices of the bipyramid. The Li(THF) 2+ cation in 4 can be replaced by the (n-C 4 H 9 ) 4 N + cation (5). The 1 H NMR spectra suggest the presence of two stereoisomers of the anionic clusters in 4 and 5 having C 3h and C s symmetry. In the reaction of η 3 -allyl- or η 3 -methallylhydrogensulfidopalladium (6, 6 a) with n-butyl-lithium crystalline compounds having the composition RC 3 H 4 PdSLi(THF)≈ 4 , R = H, CH 3 (7, 7 a) are obtained; their 1 H NMR spectra also reveal the existence of the two stereoisomers having C 3h and C s symmetry. The same type of stereoisomerism is observed with the crystalline [(n-C 4 H 9 ) 4 N] + [(η 3 -C 3 H 5 Pd) 3 S 2 ] - (8) obtained from 7 and (n-C 4 H 9 ) 4 N+ClO 4 - . For 7 and 7 a an ionic structure consisting of trigonal bipyramidal (η 3 -RC 3 H 4 Pd) 3 S 2 - anions and Li 3 S(THF) 4 + cations is proposed.

Open Access June 2, 2014

Gasphasen-Reaktionen, 35. Benzseleniren als kurzlebiges Zwischenprodukt in der Pyrolyse von 1.2.3-Benzoselenodiazol zu 6-Fulvenselon/ Benzselenirene as Short-lived Intermediate in the Pyrolysis of 1,2,3-Benzoselenodiazole to 6-Fulvenselone

Hans Bock, Sitki Aygen, Bahman Solouki

Page range: 611-615

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Abstract

In the pyrolysis of 1,2,3-benzoselenodiazole using a short-distance furnace, a short-lived intermediate is detected photoelectron spectroscopically. Mass spectra recorded under similar conditions suggest an isomer C 6 H 4 Se rearranging to the more stable final product 6-fulveneselone. The ionization pattern obtained by computerized spectra stripping is assigned to benzselenirene by molecular radical cation state comparison based on MNDO calculations.

Open Access June 2, 2014

Mikrobiologische Umwandlung von Silicium-Yerbindungen: Enantioselektive Reduktion von Acetessigsäure-(trimethylsilylalkyl)estern und deren Carba-Analoga/ Microbiological Transformation of Silicon Compounds: Enantioselective Reduction of Trimethylsilylalkyl Acetoacetates and their Carba-Analogues

Reinhold Tacke, Haryanto Linoh, Burghard Stumpf, Wolf-Rainer Abraham, Klaus Kieslich, Ludger Ernst

Page range: 616-620

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Abstract

The trimethylsilylalkyl acetoacetates 1 b and 2 b as well as their carba analogues 1 a and 2 a have been reduced microbiologically by Kloeckera corticis (ATCC 20109), leading to the corresponding ( + )-3(S)-hydroxybutanoates 3b, 4b, 3a, and 4a. The enantiomeric purity was found to be 80% (3a, 3b, 4b) and 65% (4a), respectively. The reduction of lb and 2b is - to our knowledge - the first example for a controlled microbiological transformation of organosilicon substrates.

Open Access June 2, 2014

Untersuchungen über Substituenten-Einflüsse auf die reduktive Eliminierung des Biphenyl-Systems aus cis-Bis(aryl)bis(triphenylphosphan)platin(II)-Verbindungen/ Influence of Substituents on the Reductive Elimination of the Biphenyl-System from cis-Bis(aryl)bis(triphenylphosphane)platinum(II) Compounds

Ulrich Bayer, Hans Albert Brune

Page range: 621-631

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Abstract

Compounds cis-[Pt(PPh 3 ) 2 (3-X-C 6 H 4 ) 2 ] [X = F, Cl, CF 3 , CH 3 O, (CH 3 ) 2 N] and cis- [Pt(PPh 3 ) 2 (3-X-C 6 H 4 )(Y-C 6 H 4 )] [X = F / Y = H, 4-F, 4-CF 3 , 4-CH 3 O; X = Cl/Y = 4-F; X = CF 3 /Y = 4-F; X = CH 3 O/Y = 4-F] have been synthesized and studied thermally with respect to the reductive elimination of disubstituted biphenyls. Activation parameters ⊿H≠ and ⊿S≠ are reported and discussed.

Open Access June 2, 2014

Ein Beitrag zur Frage der Existenz von d_πp_π-Binduiigsanteilen zwischen Platin und sp²-hybridisierten Kohlenstoff-Atomen in Phenyl-Platin-Verbindungen/ A Contribution on the Existence of d_πp_π-Interactions between Platinum and sp²-hybridized Carbon in Phenyl-Platinum Compounds

Ulrich Bayer, Hans Albert Brune

Page range: 632-634

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Abstract

19 F NMR chemical shifts of 14 fluorine substituted cis-Bis(phenyl)bis(triphenylphos-phane)platinum(II) compounds are discussed with respect to d π p π -interactions between platinum and sp 2 -hybridized carbon.

Open Access June 2, 2014

Zur intermediären Existenz von Ethylenfluoronium-Ionen in der Gasphase/ On the Intermediary Existence of Gaseous Ethylen Fluoronium Ions

Bernhard Ciommer, Helmut Schwarz

Page range: 635-638

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Abstract

The long-sought ethylen fluoronium ion (2) is generated as an intermediate in the dissociative ionization of 1-fluoro-2-(p-methyl)phenoxy ethane (4). However, prior to collisionally induced dissociation 2 undergoes ring-opening, associated with hydrogen migration, to form 1-fluoroethyl cation (3). Other decomposition pathways of the molecular ions of 4 involve (i) direct formation of 3 via a combination of C-O-cleavage (loss of ArO -) and [1,2] hydrogen migration (18%) and (ii) complete positional loss of the a-and β-methylene hydrogen atoms (34%). The remaining 48% of the molecular ions of 4 dissociate via anchimeric assistance of the fluorine in the elimination of ArO·, thus giving rise to the formation of 2.

Open Access June 2, 2014

Activated Nitriles in Heterocyclic Synthesis: The Reaction of Cinnamonitrile Derivatives with Active Methylene Reagents

Galal Eldin Hamza Elgemeie, Samier Anwar Elees, Ibraheim Elsakka, Mohamed Hilmy Elnagdi

Page range: 639-642

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Abstract

The reaction of substituted cinnamonitrile derivatives with cyanoacetanilide and ethyl acetoacetate is reported. Several new polyfunctional pyridine and pyran derivatives could be synthesised. The structures of the prepared compounds and the mechanisms of their formation is reported.

Open Access June 2, 2014

Amino Acids as Substrates in the Synthesis of Substituted Organocobalamins

Abdussalam Maihub, Jay W. Grate, Hui Bi Xu, Gerhard N. Schrauzer

Page range: 643-647

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Abstract

The amino acids alanine, valine, leucine, isoleucine, norvaline, α-amino butyric acid, and β -methyl aspartic acid are utilized as substrates for organocobalamin syntheses under “oxidizing/reducing” conditions. In the presence of V +3 as the reducing agent, free radicals are generated by the reaction of oxygen radicals with the amino acids through hydrogen atom abstraction. These amino acid radicals then combine with the cobalt atom of vitamin B 12 r to yield the respective organocobalamins. The cobalamin obtained from the reaction of β-methyl aspartic acid is a possible intermediate in the coenzyme B 12 dependent skeletal rearrangement of β-methyl aspartic acid to glutamic acid. HPLC analysis of the cobal-amins prepared from D, L-alanine indicates that the corrin ligand is relatively ineffective at promoting asymmetric syntheses under these conditions.

Open Access June 2, 2014

[4 + 2] -Photocycloaddition eines Organoeisendienophils mit 1.3-Dienen/ [4 + 2]-Photocycloaddition of an Organoiron Dienophile with 1,3-Dienes

R. Battaglia, C. C. Frazier, H. Kisch

Page range: 648-654

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Abstract

A tricyclic 1,1,1-tricarbonyl-2,3,1-diazaferrole derivative (1) reacts photochemically with 1,3-dienes with formation of [4 + 2]-cycloadducts. Introduction of substituents in the 1- or 1,4-positions of the diene or of electron releasing groups in the dienophile results in an inhibition of the cycloaddition. The reaction proceeds stepwise via photodissociation of carbon monoxide, coordination of the diene to iron, intramolecular photocycloaddition, and re-uptake of carbon monoxide. No cycloaddition occurs if the complexed diene is allowed to react thermally. X-ray structural analyses of 1 and its cycloadduct with 2,3-dimethylbutadiene (3d) reveal the presence of a novel type of three electron metal - diazene bond for both compounds and delocalized bonding for the diazaferrole 1.

Open Access June 2, 2014

Notizen: Synthesis of Trialkylstannanedithi ocarboxy lato Rhenium(I) Complexes [1]

Thomas Hättich, Udo Kunze

Page range: 655-657

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Abstract

Novel trialkylstannanedithiocarboxylato complexes are formed in a one-pot reaction of R 3 SnCS 2 Li (R = benzyl, methyl, cyclohexyl) with BrM(CO) 5 (M = Mn, Re) in a THF/dioxane solution. Tetracarbonylmetal species could be detected by IR spectroscopy in all cases. The more stable rhenium chelate complexes, R 3 SnCS 2 Re(CO) 4 , were isolated by chromatographic separation as yellow, low-melting solids with 10-20% yield.

Open Access June 2, 2014

Notizen: Photodimerisierung von 6-trans-Styryl-4- methoxy-2-pyr on ( = 5.6-Dehydrokawain) und cis-Isomerisierung von ( ± )-Kawain/ Photodimerisation of 6 -1 rans-Styry 1 - 4 - methoxy- 2 - pyrone ( = 5,6-Dehydrokawain) and cis-Isomerisation of (±)-Kawain

Macki Kaloga, Ilona Christiansen

Page range: 658-659

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Abstract

The photochemical transformation of 5,6-Dehydrokawain (1) to rel-(lR,6S,7S,8S)-5-methoxy-7-phenyl-8-[6-(4-methoxy-2-pyronyl)]-1-(E)-styryl-2-oxabicyclo[4,2,0]octa-4-en-3-one (2) by irradiation with a light bulb [1] is con-firmed. Kawain (3) turns out to be resistent to photochemical reaction in several tests. During irradiation by a Hg-lamp a transformation to cis-Kawain (4) takes place, however.

Open Access June 2, 2014

Notizen: The Absolute Configuration of Julifloridine

Viqar Uddin Ahmad, Sabiha Qazi

Page range: 660-660

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Abstract

The absolute configuration of julifloridine is proposed to be 2 R, 3 R, 6 R through 13 C Spectra, 1 H NMR Spectra,

About this journal

Objective
Zeitschrift fuer Naturforschung B (ZNB) publishes novel research in all areas of inorganic chemistry, organic chemistry, and analytical chemistry. In particular, the journal focuses on solid state chemistry, coordination chemistry, main group element chemistry, synthetic organic chemistry, natural product chemistry and, to a lesser extent, on analytical chemistry. For more than 65 years Zeitschrift fuer Naturforschung B has been open to contributions from all fields of experimental and theoretical chemistry. Zeitschrift fuer Naturforschung B publishes 12 issues per volume/year. Sometimes double issues occur.

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Solid state chemistry
Coordination chemistry
Main group element chemistry
Organic chemistry
Natural product chemistry

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Original (full) papers, research notes and preliminary communications, reports on specific research topics of current interest (reviews)

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Volume 38 Issue 5

Issue of Zeitschrift für Naturforschung B

Beiträge zur Chemie des Phosphors, 126. Tris(tert-butylphosphino)-phosphan, P(t-BuPH)3 - ein teilsubstituiertes Derivat von iso-P4H6/ Contributions to the Chemistry of Phosphorus, 126. Tris(tert - butylphosphino)phosphane, P(t-BuPH)3 - a Partially Substituted Derivative of iso-P4H6

Abstract

Barrier to Rotation about Sulfur-Sulfur Bonds in Homocyclic Sulfur Molecules

Abstract

Cycloaddition von Schwefelkohlenstoff an die Azidliganden in (Ph3P)2Pd(N3)2 und [Co(N3)4]2–/ Cycloaddition of Carbon Disulfide to the Azide Ligands of (Ph3P)2Pd(N3)2 and [Co(N3)4]2-

Abstract

Untersuchungen an Polypseudohalogeniden, II. Darstellung und Kristallstruktur des Rubidiumdicyanotriiodids, Rb[I(ICN)2]/ Studies on the Polypseudohalides, II. Preparation and Crystal Structure of Rb[I(ICN)2]

Abstract

Abstract

β-NbBr5, eine neue Modifikation von Niobpentabromid mit einer eindimensionalen Lagenfehlordnung/ β-NbBr5, a New Modification of Niobium Pentabromide Having One-Dimensional Stacking Disorder

Abstract

Transition Metal Complexes with Sulfur Ligands, IV. Synthesis and Reactions of Mo (IV) Complexes with the Tetradentate Thioether-thiol Ligand 2,3,8,9-Dibenzo-1,4,7,10-tetrathiadecane

Abstract

Abstract

Übergangsmetall-Carben-Komplexe, CXXX. Nucleophile Spaltung der Kohlenstoff-Fluor-Bindung in einem Fluorcarben-Komplex des Mangans/ Transition Metal Carbene Complexes, CXXX. Nucleophilic Cleavage of the Carbon-Fluorine Bond in a Fluorocarbene Complex of Manganese

Abstract

Übergangsmetall-Carben-Komplexe, CXXXI. Umsetzung von [(CO)5WCNEt2]BF4 mit anionischen Organylverbindungen von Elementen der V. Hauptgruppe/ Transition Metal Carbene Complexes, CXXXI. Reaction of [(CO)sWCNEt2]BF4 with Anionic Organyl Compounds of Group V Elements

Abstract

Abstract

η3-Allylmetall-Schwefel-Komplexe, IV/ η3-Allyl-hydrogensulfidopalladium- und -platin-Komplexe/ η3-Allylmetal-Sulfur Complexes, IV. η3-Allyl-hydrogensulfidopalladium and -platinum Complexes

Abstract

η3-Allylmetall-Schwefel-Komplexe, V. Mono- und bimetallische, mehrkernige η3-Allylmetall-Sehwefel-Komplexe des Nickels, Palladiums und Platins/ η3-Allylmetal-Sulfur Complexes, V. Mono- and Bimetallic, Polynuclear η3- Allylmetal-Sulfur Complexes of Nickel, Palladium and Platinum

Abstract

η3-Allylmeta]l-Schwefel-Komplexe, VI. Anionische η3-Allylnickel- und -palladium-Schwefel-Cluster/ η3-Allylmetal-Sulfur-Complexes, VI. Anionic η3-Allylnickel- and -palladium-Sulfur-Clusters

Abstract

Gasphasen-Reaktionen, 35. Benzseleniren als kurzlebiges Zwischenprodukt in der Pyrolyse von 1.2.3-Benzoselenodiazol zu 6-Fulvenselon/ Benzselenirene as Short-lived Intermediate in the Pyrolysis of 1,2,3-Benzoselenodiazole to 6-Fulvenselone

Abstract

Mikrobiologische Umwandlung von Silicium-Yerbindungen: Enantioselektive Reduktion von Acetessigsäure-(trimethylsilylalkyl)estern und deren Carba-Analoga/ Microbiological Transformation of Silicon Compounds: Enantioselective Reduction of Trimethylsilylalkyl Acetoacetates and their Carba-Analogues

Abstract

Abstract

Ein Beitrag zur Frage der Existenz von dπpπ-Binduiigsanteilen zwischen Platin und sp2-hybridisierten Kohlenstoff-Atomen in Phenyl-Platin-Verbindungen/ A Contribution on the Existence of dπpπ-Interactions between Platinum and sp2-hybridized Carbon in Phenyl-Platinum Compounds

Abstract

Zur intermediären Existenz von Ethylenfluoronium-Ionen in der Gasphase/ On the Intermediary Existence of Gaseous Ethylen Fluoronium Ions

Abstract

Activated Nitriles in Heterocyclic Synthesis: The Reaction of Cinnamonitrile Derivatives with Active Methylene Reagents

Abstract

Amino Acids as Substrates in the Synthesis of Substituted Organocobalamins

Abstract

[4 + 2] -Photocycloaddition eines Organoeisendienophils mit 1.3-Dienen/ [4 + 2]-Photocycloaddition of an Organoiron Dienophile with 1,3-Dienes

Abstract

Notizen: Synthesis of Trialkylstannanedithi ocarboxy lato Rhenium(I) Complexes [1]

Abstract

Notizen: Photodimerisierung von 6-trans-Styryl-4- methoxy-2-pyr on ( = 5.6-Dehydrokawain) und cis-Isomerisierung von ( ± )-Kawain/ Photodimerisation of 6 -1 rans-Styry 1 - 4 - methoxy- 2 - pyrone ( = 5,6-Dehydrokawain) and cis-Isomerisation of (±)-Kawain

Abstract

Notizen: The Absolute Configuration of Julifloridine

Abstract

Beiträge zur Chemie des Phosphors, 126. Tris(tert-butylphosphino)-phosphan, P(t-BuPH)₃ - ein teilsubstituiertes Derivat von iso-P₄H₆/ Contributions to the Chemistry of Phosphorus, 126. Tris(tert - butylphosphino)phosphane, P(t-BuPH)₃ - a Partially Substituted Derivative of iso-P₄H₆

Cycloaddition von Schwefelkohlenstoff an die Azidliganden in (Ph₃P)₂Pd(N₃)₂ und [Co(N₃)₄]^2–/ Cycloaddition of Carbon Disulfide to the Azide Ligands of (Ph₃P)₂Pd(N₃)₂ and [Co(N₃)₄]^2-

Untersuchungen an Polypseudohalogeniden, II. Darstellung und Kristallstruktur des Rubidiumdicyanotriiodids, Rb[I(ICN)₂]/ Studies on the Polypseudohalides, II. Preparation and Crystal Structure of Rb[I(ICN)₂]

β-NbBr₅, eine neue Modifikation von Niobpentabromid mit einer eindimensionalen Lagenfehlordnung/ β-NbBr₅, a New Modification of Niobium Pentabromide Having One-Dimensional Stacking Disorder

Übergangsmetall-Carben-Komplexe, CXXXI. Umsetzung von [(CO)₅WCNEt₂]BF₄ mit anionischen Organylverbindungen von Elementen der V. Hauptgruppe/ Transition Metal Carbene Complexes, CXXXI. Reaction of [(CO)sWCNEt₂]BF₄ with Anionic Organyl Compounds of Group V Elements

η³-Allylmetall-Schwefel-Komplexe, IV/ η³-Allyl-hydrogensulfidopalladium- und -platin-Komplexe/ η³-Allylmetal-Sulfur Complexes, IV. η³-Allyl-hydrogensulfidopalladium and -platinum Complexes

η³-Allylmetall-Schwefel-Komplexe, V. Mono- und bimetallische, mehrkernige η³-Allylmetall-Sehwefel-Komplexe des Nickels, Palladiums und Platins/ η³-Allylmetal-Sulfur Complexes, V. Mono- and Bimetallic, Polynuclear η³- Allylmetal-Sulfur Complexes of Nickel, Palladium and Platinum

η³-Allylmeta]l-Schwefel-Komplexe, VI. Anionische η³-Allylnickel- und -palladium-Schwefel-Cluster/ η³-Allylmetal-Sulfur-Complexes, VI. Anionic η³-Allylnickel- and -palladium-Sulfur-Clusters

Ein Beitrag zur Frage der Existenz von d_πp_π-Binduiigsanteilen zwischen Platin und sp²-hybridisierten Kohlenstoff-Atomen in Phenyl-Platin-Verbindungen/ A Contribution on the Existence of d_πp_π-Interactions between Platinum and sp²-hybridized Carbon in Phenyl-Platinum Compounds