bluuebunny/crossref_metadata_2025 huggingface dataset:
Bis(di-tert-butylphosphino)ethan-nickel(0)-Komplexe / Bis(di-tert-butylphosphino)ethane-nickel(0) Complexes
Authors: Pörschke Klaus-Richard , Pluta Christian , Proft Bernd , Lutz Frank , Krüger Carl
Published: March 2015

Ni(cdt) reacts with tBu2Bu2PC2H4P4P'Bu2 in pentane at 20°C to yield brownish crystals of (tBu2Bu2PC2H4P4P'Bu2)Ni(η2-C12H18) (1). The molecular structure of 1, as established by X-ray crystallography, exhibits a trigonal-planar coordination geometry of the nickel center with a η2bonded cdt ligand. In the crystal 1 exists as two enantiomers, which are determined by the leftor right-handed screw axis of the cdt ligand. The cdt ligand in 1 resists most typical displacement reactions but 1 reacts with CO at – 78°C to afford the colorless 18e complex (tBu2Bu2PC2H4P4P'Bu2)Ni(CO)2 (2). From the reaction of Ni(cod)2 with tBu2Bu2PC2H4P4P'Bu2 yellow needles of (tBu2Bu2PC2H4P4P'Bu2)Ni(η2-cod) (3) are obtained. Low temperature NMR spectroscopy established that only one diene C=C bond is coordinated to nickel(0). At higher temperatures a rapid exchange of the coordinated and unbound C=C bonds is induced. When solutions of 3 are kept at 20°C for several days the dinuclear, almost insoluble yellow complex {(tBu2PC2H4P4P'Bu2)Ni}2(μ-η2,η2-cod) (4) precipitates. The reaction of Ni(C2H4)3 and tBu2Bu2PC2H4P4P'Bu2 affords orange (tBu2Bu2PC2H4P4P'Bu2)Ni(C2H4) (5). From Ni(1,5-hexadiene)2 and tBu2Bu2PC2H4P4P'Bu2 in 1,5-hexadiene the yellow-greenish complex (tBu2Bu2PC2H4P4P'Bu2)Ni(η2-C6H10) (6) is obtained. As for 3, only one diene C=C bond is coordinated to nickel(0), but the structure is fluxional with exchange of the coordinated and unbound C=C bonds (NMR at 20°C). From a solution of 6 in pentane the dinuclear, diastereomeric compounds rac/meso-{(tBu2PC2H4P4P'Bu2)Ni}2(μ-η2,η2-C6H10) (7a,b) separate in large yellow crystals. In similar reactions the 1,6-heptadiene complexes (tBu2Bu2PC2H4PtBu2)Ni(η2-C7H12) (8) and rac/meso-{(tBu2Bu2PC2H4PtBu2)Ni}2(µ-η2μ-η2,η2-C7H12) (9a,b) are also obtained. In 6, 7a,b, 8, and 9a,b the open-chain diene ligands can easily be displaced, e.g., by ethene to afford 5. Thus, complexes 6, 7a,b, 8, 9a, b are the most reactive. These complexes react readily (the ethene derivative 5 also reacts but very slowly) with butadiene to yield large yellow cubes of (tBu2Bu2PC2H4P4P'Bu2)Ni(η72-C4H6) (10), which is also fluxional. The alkene complexes 5, 6, 7a, b, 8, 9a,b, 10 react with ethyne to yield yellow-brownish crystalline (tBu2
tBu2PC2H4P4P'Bu2)Ni(C2H2) (11).
N-Methylimidazole Mediated Chemistry of Transition Metal Phenylthiolates. The Isolation of the Perthiolate Salts [M(N-MeIm)6](S2Ph)2
Authors: Krautscheid Ulrike , Dev Somanath , Krautscheid Harald , Paul Partha P. , Wilson Scott R. , Rauchfuss Thomas B.
Published: March 2015

Salts of the composition [M(N-MeIm)6](SPh)2 (M = Mn, Ni; N-MeIm = N-methylimidazole) were prepared by dissolution of the metal powders with N-MeIm solutions of Ph2S2. X-ray crystallographic examination established that these salts indeed feature uncoordinated PhS-. The salts [M(N-McIm)6](SPh)2 (M = Mn, Ni) react with S8 to give [M(N-MeIm)6]S8 via the intermediacy of the perthiolate salts [M(N-MeIm)6](S2Ph)2.
Darstellung und Einkristall-Röntgenstrukturanalyse einiger Fluorphosphite und Phosphitester / Preparation and Single Crystal X-Ray Diffraction Study of Some Fluorophosphites and Phosphite Esters
Authors: Meyer Thomas G. , Fischer Axel , Jones Peter G. , Schmutzler Reinhard
Published: March 2015

The synthesis of some monofluorophosphite esters from the appropriate hydroxy compound and PCl2F in the presence of a tertiary amine is described. The reaction of 2,2′-dihydroxy-biphenyl with PCl3 in the presence of triethylamine did not furnish the expected chlorophosphite 9; instead, the bridged bisphosphite ester, 10, was obtained. Reaction of the fluorophosphite ester 8 with 3,5-di-tert-butyl-benzoquinone furnished the spiromonofluorophosphorane 12 in which λ5P is part of a five-membered and a seven-membered ring system. Single crystal X-ray diffraction studies were conducted on compounds 2, 10 and 13. In the case of 2, crystallographic 2/m symmetry and short intermolecular P · · · O distances were observed. Compound 10 shows short intramolecular P · · · O contacts. The catechyl phosphate 13, similarly to other dialkylphosphate esters, was found to be a hydrogen-bonded dimer.
Erste strukturelle Charakterisierung eines leicht oxidierbaren 1,4-Dihydrochinoxalin-Derivats / First Structural Characterization of an Easily Oxidized Derivative of 1,4-Dihydroquinoxaline
Authors: Lichtblau Alexander , Hausen Hans-Dieter , Kaim Wolfgang
Published: March 2015

The first crystal structure analysis of a 1,4-dihydroquinoxaline is described by example of the 1,4-bis(tert-butyldimethylsilyl) derivative. In the solid state, this molecule exhibits a nonplanar heterocycle with a dihedral angle of 156.3° along the N—N axis in the boat-shaped 8π electron ring system. The alkyl groups of the Si(tert-Bu)Me2 substituents are arranged as to minimize steric repulsion. Despite the reduced π electron conjugation due to non-planarity, the compound is oxidized reversibly to an EPR detectable radical cation at —0.59 V vs. ferrocene in dichloromethane. However, the second oxidation to the fully aromatic dication is electrochemically irreversible. A comparison with previously obtained results illustrates the structural flexibility of the non-aromatic 1,4-dihydro-1,4-diazine ring system which is strongly affected by rather weak non-bonded interactions.
Schwingungsspektren und Normalkoordinatenanalyse der 35Cl/37Cl-isotopierten Chloro-Iodo-Osmate(IV), [OsClnI6-n]2-, n = 0-6 / Vibrational Spectra and Normal Coordinate Analysis of the 35Cl/37Cl Labelled Chloro-Iodo-Osmates(IV), [OsClnI6-n]2-, n = 0-6
Authors: Manthey M. , Preetz W.
Published: March 2015

All components of the two series [Os35ClnI6-n]2- and [Os37ClnI6-n]2-, n = 0-6, including the pairs of geometric isomers for n = 2, 3, 4, have been prepared and isolated by ion exchange chromatography on DEAE cellulose. The highly resolved low temperature (80 K) IR and Raman spectra of the pure isotopomers show distinct isotopic shifts for different vibrational modes up to 10 cm-1. Normal coordinate analyses have been performed, based on a general valence force field. Due to the stronger trans influence of I as compared to Cl in all asymmetric Cl˙—Os—I′ axes the Os—I′ bonds are strengthened and the Os—Cl˙ bonds are weakened, as indicated by valence force constants for Os—I′ approximately 9% higher, for Os—Cl˙ 7% lower, as compared with the values calculated for symmetric axes.
Phenylalanine: Its ˙OH and SO4˙⁻-Induced Oxidation and Decarboxylation. A Pulse Radiolysis and Product Analysis Study
Authors: Wang Degui , Schuchmann Heinz-Peter , von Sonntag Clemens
Published: March 2015

Phenylamine has been oxidized by radiolytically generated hydroxyl and sulfate radicals, the ensuing intermediates and their reactions have been studied by pulse radiolysis and product analysis in the absence and presence of oxidants such as Fe(CN)6
3- and O2. Upon OH radical attack, hydroxycyclohexadienyl-type radicals are mainly formed while Η-abstraction reactions can be neglected. In the presence of Fe(CN)6
3- these radicals are for the most part oxidized to the corresponding tyrosines (80%), except for the ipso-OH-adduct radicals (≈ 20%). It is concluded that ˙OH-addition is almost random, but with a slight avoidance of the metaposition relative to the ortho-, para- and ipso-positions. Oxygen adds reversibly to the OH-adduct radicals (kf = 1.8 × 108 dm3 mol-1 s-1, kr = 5.4 × 104 s-1). In this case, tyrosine formation occurs by HO2˙-elimination. However, due to side reactions, tyrosine formation only reaches 52% of the OH radical yield. The tyrosine yield drops to 10% in the absence of an oxidant.

Upon SO4˙⁻-attack, decarboxylation becomes a major process (33% of SO4˙⁻) alongside the production of tyrosines (43%). Here, with Fe(CN)6
3- as the oxidant the formation of p-Tyr (18.5%) and m-Tyr (16.5%) is preferred over o-Tyr formation (8.5%). It is believed that in analogy to other systems a radical cation is formed immediately upon SO4˙⁻-attack which either reacts with water under the formation of hydroxycyclohexadienyl-type (“OH-adduct”) radicals, or decarboxylates after intramolecular electron transfer. The radical cation can also arise indirectly through H+-catalysed water elimination from the ˙OH-adduct radicals. At pH 2 and a dose rate of 0.0046 Gy s-1 CO2 formation matches the OH radical yield when ˙OH is the attacking radical. Below pH 2, G(CO2) decreases with falling pH. This indicates the occurrence of another, unimolecular, pathway under these conditions competing effectively with decarboxylation. This appears to be a relatively slow deprotonation reaction of the carboxylprotonated phenylalanine radical cation which gives rise to the benzyl-type radical.
Thiocarbonyl Complexes of Rhenium. Part I.
Authors: Abram Ulrich , Lorenz Bernd
Published: March 2015

Novel rhenium complexes with terminal thiocarbonyl groups have been synthesized from ReCl3(Me2PhP)3 and sodium diethyldithiocarbamate. mer-(Diethyldithiocarbamato)tris-(dimethylphenylphosphine)(thiocarbonyl)rhenium(I), mer-[Re(CS)(Me2PhP)3(Et2dtc)], and tris(diethyldithiocarbamato)(thiocarbonyl)rhenium(III), [Re(CS)(Et2dtc)3] have been studied by infrared and NMR spectroscopy, mass spectrometry and X-ray diffraction.

mer-[Re(CS)(Me2PhP)3(Et2dtc)] crystallizes orthorhombic in the space group Pna21 with a = 1516.1(2), b = 2189.8(2) and c = 1035.6(1) pm. Structure solution and refinement converged at R = 0.042. The coordination geometry is a distorted octahedron. The Re—C bond length is found to be 184(2) pm.

[Re(CS)(Et2dtc)3] crystallizes monoclinic in the space group P21/c with a = 962.2(6), b = 1744.0(2), c = 1537.4(6) pm and β = 96.21(1)°. The final R value is 0.028. In the monomeric complex the rhenium atom is seven-coordinate with an approximate pentagonal-bipyramidal coordination sphere and a rhenium-carbon distance of 181(1) pm.
Tris(trimethylphosphine)cobalt(0) Compounds Containing Azaolefinic Ligands — Syntheses and Structures of Benzo[c]cinnoline and Phenylisocyanate Complexes
Authors: Klein Hans-Friedrich , Helwig Michael , Karnop Michael , König Herbert , Hammerschmitt Birgit , Cordier Gerhard , Flörke Ulrich , Haupt Hans-Jürgen
Published: March 2015

Mononuclear cobalt(0) complexes Co(η2-azaolefin)(PMe3)3 (azaolefin = benzo[c]cinnoline (1), p-dimethylamino-phenyl(phenyl)diazene (2), 1/2 diazobenzene (3), bis(p-tolyl)diazene (4), bis(p-fluorphenyl)diazene (5), bis(p-trifluoromethyl-phenyl)diazene (6), phenylisocyanate (7)) are obtained from Co(cyclo-C5H8)(PMe3)3 by substitution of the olefin. X-ray crystal structure determinations of 1 and 7 show tetrahedral arrangements of ligands around the cobalt atom. By reaction with carbon monoxide carbonyl(phosphine)cobalt(0) complexes are formed. 7 catalyses the cyclotrimerization of phenylisocyanate, while with CoCl(PMe3)3 as a catalyst the cyclic dimer of phenylisocyanate is selectively formed. A convenient synthesis for CoCl(PMe3)3 is described.
Sr3[MnN3] und Ba3[MnN3], die ersten Nitridomanganate(III): Trigonal-planare Anionen [MnIIIN3]6- / Sr3[MnN3] and Ba3[MnN3], the First Nitridomanganates(III): Trigonal-Planar Anions [MnIIIN3]6-
Authors: Tennstedt Andreas , Röhr Caroline , Kniep Rüdiger
Published: March 2015

Sr3[MnN3] (hexag. P63/m (Nr. 176); a = 764.2(1) pm, c = 529.8(1) pm; Z = 2) and Ba3[MnN3] (hexag. P63/m (Nr. 176); a = 805.0(2) pm, c = 558.6(1) pm; Z = 2) are isotypes of the Ba3[FeN3] crystal structure and contain trigonal-planar anions [MnN3]6- with D3h-symmetry (Mn—N: 174.1(13) pm/173.7(12) pm). The compounds were prepared by reaction of mixtures of Li, Sr/Ba and Mn (molar ratio 2:1:1) in tungsten crucibles with nitrogen (1 atm) at 850°C.
Antagonists of LHRH with Histidine in the Priority Position 8
Authors: Janecka Anna , Shan Si-Mei , Bowers Cyril , Folkers Karl
Published: March 2015

Sixteen new designs of antagonists of the luteinizing hormone releasing hormone (LHRH) with histidine in position 8 were synthesized, because this position is critical both for antiovulatory activity and the side effect of histamine release. The most potent antagonist was NAcDQal-DpClPhe–D 3 Pal– Ser–cPzACAla–DPicLys– Leu– His – Pro –DAlaNH2, which showed 33% AOA at 0.25 μg. The histamine release was remarkably negligible by an ED50 of 308 μg/ml which is superior to 186 μg/ml for LHRH and comparable to 300 for Antide.

The relative basicities of His, Arg, and ILys in position 8 of antagonists appear to influence both the level of potency of AOA and a negligible to a significant release of histamine. The least basic His8-analogs can have the lowest AOA and the highest ED50. The very basic Arg8-analogs can have the highest AOA and the lowest ED50. The moderately basic ILys8-analogs can be a compromise for acceptable levels of potency and safety.
Notizen: Darstellung und Struktur von CaPtGa2 / Preparation and Structure of CaPtGa2
Authors: Dascoulidou-Gritner K. , Schuster H.-U.
Published: March 2015

The new compound CaPtGa2 crystallizes in a MgCuAl2 type structure, orthorhombic system, space group C mcm (No. 63) with the lattice constants: a = 425,8(1), b = 1025,1(2), c = 698,8(1) pm.
Notizen: Auflösung von Palladium- und Platinpulver durch biogene Stoffe / Dissolution of Palladium and Platinum Powder by Biogenic Compounds
Authors: Freiesleben Doris , Wagner Barbara , Hartl Helmut , Beck Wolfgang , Hollstein Michael , Lux Franz
Published: March 2015

Palladium and platinum powder dissolve at room temperature in oxygen saturated solutions of α-amino acids, peptides, nucleosides and ATP.

The resulting mass concentrations of dissolved palladium and platinum were in the range from 10 to 100 μg/ml.
Das 2-Halogen-5,6-benzo-1,3,2-dioxaphosphorinan-4-on-Ringsystem / The 2-Halogeno-5,6-benzo-1,3,2-dioxaphosphorinan-4-one Ring System
Authors: Gast Rainer , Kaukorat Thomas , Neda Ion , Schmutzler Reinhard
Published: March 2015

The reaction of salicylic acid with phosphorus trichloride furnished the previously known 2-chloro-5,6-benzo-1,3,2-dioxaphosphorinan-4-one heterocycle 1 which was unambiguously characterized, for the first time, by NMR spectroscopy and mass spectrometry. The fluorine and bromine analogues of 1, 2 and 3 were synthesized from 1, using exchange reactions. The iodo derivative, 4, owing to its instability, could be identified only in the reaction mixture by 1H and 31P NMR spectroscopy. The amine derivatives 5-8 were obtained from 1 using standard exchange reactions, either with silylated amines or with secondary amines in the presence of base. There was no evidence by 1H NMR spectroscopy for intramolecular Me2N→P coordination in 6. The 31P NMR investigation of 7 revealed the presence of two rotational isomers, presumably as a result of steric hindrance at the P–N bond by the methyl substituent of the piperidine group. The reaction of 6 with methyl iodide led to methylation at the nitrogen atom of the Me2N group, producing the ammonium iodide, 9. The reactions of 5,6 and 8 with norbornadiene tetracarbonyl molybdenum failed to furnish isolable products.
Determination of the Stability of Some Dithiophosphinate Complexes of Silver by Potentiometry
Authors: Malakova Hristina G. , Vasileva Aksinia E.
Published: March 2015

To characterize the stability of dithiophosphinate complexes of silver the value of their ion product (IP) has been determined by potentiometry. Complexes with ethyl-, n-propyl-, and phenyl- radicals have been studied. The composition of the complexes (Ag+ : L = 1:1) has been determined using the relationship E/lgCL.
Metallkomplexe mit 1,4,7-Trithiacyclononan: Kristallstrukturen von [CdI2 · C6H12S3]2 und [Hg(C6H12S3)2](HgI3)2 / Metal Complexes with 1,4,7-Trithiacyclononane: Crystal Structures of [CdI2 · C6H12S3]2 and [Hg(C6H12S3)2](HgI3)2
Authors: Pickardt Joachim , Shen Jing
Published: March 2015

Crystals of the complexes [CdI2 · C6H12S3]2 (1) and [Hg(C6H12S3)2](HgI3)2 (2) were obtained by diffusion of 1,4,7-trithiacyclononane (9 S 3) in ethanol into aqueous solutions of cadmium iodide and mercuric iodide/potassium iodide, resp. Both compounds crystallize monoclinically,1: space group P21/n, Z = 4, a = 1207.1(5), b = 909.9(2), c = 1240.3(7) pm, β = 92.59(9)°; 2: P21/c, Z = 2, a = 804.7(6), b = 934.0(6), c = 2167.9(4) pm, β = 94.34(7)°. 1 is dimeric, consisting of two [CdI2 · 9S3] units, connected via iodine bridges. Crystals of 2 contain sandwich-like cations [Hg(9S3)2]2+ and [HgI3]- anions, forming chains via Hg ··· S and Hg ··· I bridges.
Totalsynthese von Thymosin /β4, 3[1,2] Klassische Synthese des Fragments [31 -43] von Thymosin ß4 / Total Synthesis of Thymosin β4, 3[1, 2] Conventional Synthesis of the Fragment [31-43] of Thymosin β4
Authors: Link Peter , Voelter Wolfgang
Published: March 2015

As part of our total synthesis of thymosin β4 an optimized synthesis of the C-terminal part of thymosin β4 is described. Side chain functional residues of the tridecapeptide are masked by tert-butyl and the α-amino residues are protected by Z groups. The fully protected peptide derivative was obtained by WSCI/HOBt coupling of three fragments representing the segments [31-35], [36-37] and [38-43].
Darstellung und Kristallstruktur von K49Tl108 / Preparation and Crystal Structure of K49T1108
Authors: Cordier Gerhard , Müller Volker
Published: March 2015

K49T1108 was prepared from the elements (molar ratio K: Tl = 1:2) at 700 K. The crystal structure was determined by single crystal X-ray diffraction methods (a = 1728.7(1) pm, Pm 3, Z = 1, R = 0.086). It contains T112 icosahedra and Tl12 truncated tetrahedra (Kasper polyhedra). 20 truncated tetrahedra form Tl84-polyhedra (Samson polyhedra) by sharing hexagonal faces. These polyhedra are connected by common edges. Folded Tl13-chains connect the icosahedra and the Samson polyhedra to a framework. The truncated tetrahedra are occupied by potassium atoms.
Cyclische Schwefeldiimide des Siliciums. 15N-NMR-Spektroskopie und die Röntgenstrukturanalyse des Achtrings tBu2Si(NSN)2SitBu2 / Cyclic Sulfur Diimides of Silicon. 15N NMR Spectroscopy and the X-Ray Analysis of the Eight-Membered Ring tBu2Si(NSN)2SitBu2
Authors: Herberhold Max , Gerstmann Silke , Milius Wolfgang , Wrackmeyer Bernd
Published: March 2015

Various six-membered cyclic sulfur diimides (3a—f) were prepared by aminolysis of the bis(chloro-dimethylsilyl)sulfur diimide (2) using NH3 (a) and primary amines RNH2 [R = Me (b), Et (c), nPr (d), nBu (e), iPr (f)]. Except for R = H, non-cyclic intermediates, the Si-monoamino- (7) and Si,Si′-diamino derivatives of 2 (8), were detetected for all groups R, including R = tBu (g). The reaction between R2SiCl2 and the sulfur diimide anion K[(NSN)SiMe3] gave non-cyclic silanes (9,10) and the eight-membered rings of the type R2Si(NSN)2SiR2 [R = Me (4), tBu (5)] of which 5 was studied by X-ray analysis (monoclinic, space group P21/c; planar ring system) and solid-state 15N and 29Si CP/MAS NMR spectroscopy. The ten-membered ring system 6 was obtained from the reaction between 1,2-dichlorotetramethyldisilane and bis(trimethylstannyl)sulfur diimide. All compounds were studied by 1H,13C, 15N and 29Si NMR. The δ15N NMR data proved useful to distinguish between fluxional systems with fast E/Z—Z/E isomerization (non-cyclic compounds 8 and the ten-membered cycle 6). Hahn-Echo-extended (HEED) polarization transfer (INEPT) pulse sequences served to measure coupling constants 1J(29Si15Namine) for the compounds 3 and 8. This also proved that the magnitude of 1J(29Si15NNSN) must be small (< 1 Hz). In the case of the compounds 3, the rather small magnitude of both 1J(29Si15Namine) and 1J(15N1H) (3a) indicated that the aminonitrogen atom adopts a pyramidal environment.
Funktionalisierte 1,1-Ethendithiolate als Liganden, II / Functionalized 1,1-Ethene Dithiolates as Ligands, II
Authors: Weigand Wolfgang , Saumweber Rupert , Schulz Peter
Published: March 2015

para-Substituted β-ketodithiocinnamic acid dianions react with L2MCl2 [M = Ni, L = PBu3; M = Pd, L = PPh3; M = Pt, L = PEt3, PBu3, PPh2Tol, 1/2 dppe, 1/2 2,9-dimethyl-1,10-phenanthroline (dmphen)] to give the 1,1-ethene dithiolate complexes L2M[S2C=CH-C(O)-C6H4p-OCnH2n-1] (3: M = Ni, L = PBu3, n = 12; 4a, b: M = Pd, L = PPh3, n = 1,8; 5a: M = Pt, L = PEt3, n = 1; 5b, 5e-g; 5i: M = Pt, L = PPh3, n = 1,8,10,12,14; 5c, h: M = Pt, L = 1/2 dppe, n = 1,12; 5j: M = Pt, L = PPh2Tol, n = 12; 6 a-c M = Pt, L = 1/2 dmphen, n = 8, 12, 16); L2Pt[S2C=CH-C(O)-C6H4-p-C12H25] (7 a, b: L = PPh3, 1/2 dmphen), (Ph3P)2Pt[S2C=CH-C(O)-C6H4-p-C6H5] (8) and L2M[S2C=CH-C(O)-C4H3S] (9a: M = Pd, L = PPh3; 9b: M = Pt, L = PEt3; 9c: M = Pt, L = PPh3, 9d: M = Pt, L = 1/2 dppe). These compounds have been characterized by their UV, IR, 1H, 13C and 31P NMR spectra.
Reaktionen von ausgewählten fluorierten Ketonen und (Me3Si)2NP=NSiMe3 / Reactions of Selected Fluorinated Ketones and (Me3Si)2NP=NSiMe3
Authors: Seifert Frank Uwe , Röschenthaler Gerd-Volker
Published: March 2015

The iminophosphine (Me3Si)2NP=NSiMe3 (1) was found to add pentafluoroacetone (2) giving two oxaphosphiranes (3a,b) (isomer ratio 2:3), whereas trifluoromethylpyruvate (4) gave rise to both a three-membered and a five-membered ring system (ratio 2:1) containing λ5σ4-phosphorus (5a,b) (isomer ratio 5:4) and 6, respectively. Pentafluoropropene-2-ol (7) (tautomer of 2), and 1 form the diamidophosphite 8 in a [2+2] addition reaction. Two 1,2λ5σ4-oxaphosphols 10a,b (isomer ratio 5:1) were synthesized from bifunctional 2-trifluoroacetylphenol 9 and 1. Hexafluoroacetone (11) added to 10a,b to yield only the λ5σ4-oxazaphosphetane (12).
Amidinadditionsprodukte des 1,2,3-Indantrionhydrats: Synthese und Strukturzuordnung durch Kristallstrukturanalyse, spektrale Daten und Blei(IV)acetatoxidation / Products of Amidinaddition to 1,2,3-Triketohydrindenhydrat: Synthesis and Determination by Crystal Structure, Spectral Data and Oxidation with Lead(IV)acetate
Authors: Hemmerling Hans-Jörg , Janoschka Margarete , Wunderlich Hartmut
Published: March 2015

The addition of amidines to 1,2,3-triketohydrindenhydrat gives cyclic dihydroxyindenoimidazoles. From N-substituted amidines mixtures of regioisomeric derivatives were obtained. Analysis of crystals revealed the major product of 2k to be 4k. They belong to the monoclinic space group P21/c (a = 889.1(2); b = 1186.6(3); c = 2783.5(7) pm; β = 91.26(2)°) with Ζ = 8 molecules including four molecules of ethanole per unit cell. These results were confirmed by oxidation with lead(IV)acetate, which lead to derivatives of isoindols.
Synthese und Kristallstrukturen der Wolfram(VI)-Alkinkomplexe [WCl4(Ph - C≡C - I)(THF)] und [WCl4(Ph-C≡C-Te-C4H9)(THF)] / Synthesis and Crystal Structures of the Tungsten(VI) Alkyne Complexes [WCl4(Ph-C≡C-I)(THF)] and [WCl4(Ph-C≡C-Te-C4H9)(THF)]
Authors: Plate Michael , Hofacker Peter , Massa Werner , Schwarz Birgit , Neumüller Bernhard , Dehnicke Kurt
Published: March 2015

[WCl4(Ph-C≡C-I)(THF)] has been prepared by the reaction of trans-[WCl4(SEt2)2] with Ph - C≡C - I in THF solution, whereas [WCl4(Ph-C≡C-Te-nC4H9)(THF)] has been synthesized by the reaction of Ph-C≡C-Te-nC4H9 with tungsten hexacloride in the presence of C2Cl4 and THF. Both complexes were characterized by IR spectroscopy and by crystal structure determinations.

[WCl4(Ph-C≡C-I)(THF)]: Space group P21/c, Z = 4, 2617 observed unique reflections, R = 0.064. Lattice dimensions at –70°C: a = 1518.2(3), b = 714.5(1), c = 1540.0(3) pm, β = 90.09(3)°.

[WCl4(Ph-C≡C-Te–nC4H9)(THF)]. Space group P1̄, Z = 2, 3911 observed unique reflections, R = 0.067. Lattice dimensions at 20°C: a = 844.0(3), b = 974.6(4), c = 1002.4(3) pm, α = 76.00(4), β= 105.14(1), γ = 82.03(3)°.

Both complexes have molecular structures, in which the tungsten atoms are seven-coordi-nate by four chlorine ligands, by the two alkyne carbon atoms, and in trans position to the latter by the oxygen atom of the THF molecule. The WC bond lengths are 198 and 200(1) in the telluro complex and 206 and 196(1) pm in the iodine derivative.
195Pt- und 19F-NMR-Spektren der Fluoro-Chloro-Platinate(IV), [PtFnCl6-n]2-, n = 0-6 / 195Pt and 19F NMR Spectra of the Fluoro-Chloro-Platinates(IV), [PtFnCl6-n]2-, n = 0-6
Authors: Parzich E. , Peters G. , Preetz W.
Published: March 2015

The 10 complex ions of the system [PtFnCl6-n]2-, n = 0—6, including the three pairs of stereoisomers for n = 2, 3, 4 have been characterized by 195Pt and 19F NMR spectroscopy in CD2Cl2 solution. A wide range from 4731 ([PtCl6]2-) to 11816 ppm ([PtF6]2-) is covered by the clearly separated 195Pt resonances. The chemical shift δ(195Pt) depends nearly linearly on the sum of the electronegativities of the ligands. In accordance with increasing deshielding of the 195Pt nucleus by increasing coordination with F ligands an averaged major downfield shift of 1181 ppm per substitution of Cl by F is observed, while a minor averaged value of 354 ppm downfield is found for the trans/mer isomers in comparison to the related cis/fac isomers. Coupling with 19F results in characteristic 195Pt multiplets, with 1J(PtF) coupling constants for symmetric F—Pt—F axes of averaged 1890 Hz about 31% larger than 1J(PtF•) for asymmetric F•—Pt—Cl′ axes with averaged 1296 Hz. The data reflect the trans influence of the ligands. Highly resolved and expanded 195Pt spectra reveal clearly separated isotopomer signals with intensities according to the expected statistical ratios given by the natural abundance of 35Cl and 37Cl. For [Pt35Cln
37Cl6-n]2- five distinct signals related to n = 6-2 with 0,18 ppm highfield shift per 37Cl atom have been reliably assigned. Resolved isotopomer peaks have also been observed for mer-[PtF3
35Cl3]2-/mer-[PtF3
35Cl2
37Cl]2- with 0,21 ppm and for [PtF5
35Cl]2/[PtF5
37Cl]2- with 0,32 ppm highfield shift per 37Cl atom, respectively. The 19F resonances of symmetric axes appear at higher field, in the range from —357 to —382 ppm, than those of asymmetric axes, from —266 to —287 ppm. Under high resolution compounds with inequivalent F nuclei show multiplets originating from homonuclear 2J(FF•) couplings of about 40 Hz.
Synthesen und Strukturen sechsgliedriger Cyclometallaphosphazene von Tellur(IV) und Rhenium(VII) / Syntheses and Structures of Six-Membered Cyclometallaphosphazenes Containing Tellurium(IV) and Rhenium(VII)
Authors: Leichtweis Iring , Hasselbring Reinhard , Herbert W. , Noltemeyer Mathias , Herzog Axel
Published: March 2015

The reactions of the tridentate ligands (Me3Si)2NC(4-RC6H4)NPPh,NSiMe3 [(1): R=H, (2): R=CF3] with Re2O7 yield the six-membered rings

, (4): R=CF3]. The acyclic compound Me3SiNC(4-CF3C6H4)NPPh2NReO2OSiMe3 (5) has been obtained by reaction of 2 with Me3SiOReO3- 2 reacts quantitatively with TeCl4 to form the metallacycle

. The molecular structures of 4·CH2Cl2 and 6 · pyridine · 0.5 toluene have been determined by X-ray diffraction.
Die Darstellung von Trifluormethylnitrylhexafluorometallaten CF2N(O)H+MF6
-, Trifluormethylhydroxylammoniumhexafluorometallaten CF3NH2OH+MF6- (M = As, Sb) und Kristallstruktur von CF3NH2OH+AsF6
- / Preparation of Trifluoromethylnitryl-Hexafluorometallates CF3N(O)H+MF6
-, Trifluoromethylhydroxylammonium-Hexafluorometallates CF3NH2OH+MF6
- (M = As, Sb) and Crystal Structure of CF3NH2OH+AsF6
Authors: Minkwitz Rolf , Preut Hans , Seifert Mathias , Lamek Dirk
Published: March 2015

The preparation of CF3N(O)H+MF6- and CF3NH2OH+MF6- (M = As, Sb) and the crystal structure of CF3NH2OH+AsF6
- are reported. CF3N(O)H+MF6
- is prepared by protonation of CF3NO in the superacid system HF/MF5 (M = As, Sb). With an excess of CF3NO the cation CF3NH2OH+MF6- is formed. CF3NH2OH+AsF6
- crystallizes in the triclinic space group P T with a = 5.071(2), b = 8.297(3), c = 8.882(4) Å, α = 90.93(4)°, β = 95.49(4)°, γ = 102.96(4)° and Z = 2. It is formed by a redox reaction between CF3N(O)H+ and excess CF3NO.
Ternary Complexes in Solution+ with Phosphonates as Ligands. Intramolecular Equilibria in the Mixed Ligand Cu2+ Complexes Formed by 2,2′-Bipyridyl or 1,10-Phenanthroline and the Dianion of Phosphonylmethoxyethane in Water-Dioxane Mixtures
Authors: Bastian Matthias , Chen Dong , Gregáň Fridrich , Liang Guogang , Sigel Helmut
Published: March 2015

The stability constants of the mixed ligand complexes formed by Cu2+, 2,2′-bipyridyl or 1,10-phenanthroline (= Arm), and the dianion of phosphonylmethoxyethane (PME2-), ethyl phosphonate (EtP2-), methyl phosphonate (MeP2-), or D-ribose 5′-monophosphate (RibMP2-) (= R–PO3
2-) were determined by potentiometric pH titrations in water containing 30 or 50% (v/v) 1,4-dioxane (I = 0.1 M, NaNO3; 25°C). The corresponding results regarding water as solvent were taken from our earlier work. Previous measurements with simple phosphate monoesters, together with the present results for RibMP2-, were used to establish log

versus

straight line plots. With the aid of the equilibrium constants determined for the MeP2- and EtP2- systems it is shown that simple phosphonates, i.e., those without an additional binding site, fit also on the same straight lines. Therefore, it could be demonstrated with these reference lines that the Cu(Arm)(PME) complexes in all solvents have a higher stability than expected for a sole phosphonate Cu2+ coordination. This increased stability is attributed to the formation of 5-membered chelates involving the ether oxygen present in the – CH2– O – CH2–PO3
2- residue of PME2-. The formation degree of the 5-membered chelates in the Cu(Arm)(PME) systems varies only between about 65 and 85% in the three mentioned solvents, despite the fact that the stabilities of the Cu(Arm)(PME) complexes increase by more than 1.8 log units by going from water to 50% dioxane-water. It is concluded that (i) such 5-membered chelates will also be formed in mixed ligand complexes of other metal ions in solvents with a reduced polarity, and (ii), more importantly, that the same interactions will also occur with the parent compound of PME2-, i.e. the dianion of 9-(2-phosphonylmethoxyethyl)adenine (PMEA2-), a compound which shows antiviral properties and for which the ether oxygen is important.
Notizen: Kristall- und Molekülstruktur von 2,2-Bis(hydroxymethyl)propionsäure / Crystal and Molecular Structure of 2,2-Bis(hydroxymethyl)propionic Acid
Authors: Müller Gerhard , Lachmann Joachim , Wunderle Joachim
Published: March 2015

According to the molecular structure of 2,2-bis(hydroxymethyl)propionic acid (P 31, a = b = 6.051(1), b = 15.118(2) A, V = 479.4 Å3,Z= 3, wR = 0.047) the corresponding carboxylate should be a good anionic oxygen tripod ligand for hard metal ions with a span of the coordinating oxygen atoms of about 2.7 A.
Notizen: Naturstoffchemie,165. Mitteilung Die Synthese des 4-Acetoxy-(E)-3-(3-methyl-1,3-butadien-1-yl)-2(1 H)-chinolinon, eine potentielle Vorstufe zu dimeren Chinolonalkaloiden [2] / Chemistry of Natural Products, Part 165 The Synthesis of 4-Acetoxy-(E)-3-(3-methyl-1,3-butadien-1-yl)-2(1 H)-quinolinone, a Potential Precursor of Dimeric Quinolone Alkaloids [2]
Authors: Reisch Johannes , Bathe Andreas
Published: March 2015

A synthesis of 4-acetoxy-(E)-3-(3-methyl-1,3-butadien-1-yl)-2(1 H)-quinolinone by dehydration of 4-acetoxy-(E)-3-(2-hydroxy-3-methylbuten-1-yl)-2(1 H)-quinolinone is described.
15N and 77Se Nuclear Magnetic Resonance Study of Selenium Diimides and Aminoselenanes
Authors: Wrackmeyer Bernd , Distler Berthold , Gerstmann Silke , Herberhold Max
Published: March 2015

Selenium diimides R(NSeN)R [R = tBu (1a), tOct (1b)], the eight-membered heterocycle tBuN(SeSeSe)2NtBu (2) and the aminoselenanes of the type [R(Cl3Si)N]2Se (4a,b) and [(Me3Si)2N]2Se (5) were studied by multinuclear NMR with emphasis on 15N NMR for detection of coupling constants J(77Se15N). The selenium diimides possess the largest values of 1J(77Se15N) observed so far (1a: 158.4 and 163.5 Hz; 1 b: 158.6 and 162.8 Hz). Compound 1 b was found to be much more stable than 1a, the heterocycle 2 being the major decomposition product of 1a. The selenium diimides (1a,b) react readily with hexachlorodisilane to give the bis[alkyl(trichlorosilyl)amino]selenanes 4a,b. The solid state 13C, 15N, 29Si and 77Se CP/MAS NMR spectra of bis[bis(trimethylsilyl)amino]selenane (5) gave results in accord with the known crystal structure, and there is agreement with the solution state NMR data
Neue In2P2-Vierringe. Synthese und Kristallstrukturen von [{iPrIn(μ-tBu2P)Cl}2] und [{Me3SiCH2In(μ-tBu2P)Cl}2] / New Four-Membered In2P2 Rings. Snythesis and Crystal Structures of [{iPrIn(μ-tBu2P)Cl}2] and [{Me3SiCH2In(μ-tBu2P)Cl}2]
Authors: Merzweiler Kurt , Brands Ludwig , Spohn Jürgen
Published: March 2015

The reaction of organoindium halides RInCl2 with tBu2PSiMe3 leads to compounds of the type [{RIn(μ-tBu2P)Cl}2] (R = iPr: 1, Me3SiCH2: 2). According to the crystal structure determinations 1 and 2 contain planar In2P2 rings. The In atoms are coordinated to two bridging tBu2P groups, a terminal alkyl group and a terminal Cl atom
Ionische Kronenetherkomplexe von Thallium(I), Blei(II) und Indium(III). Die Kristallstrukturen von [T1(12-Krone-4)2] [SbC6], [Pb(15-Krone-5)2] [SbCl6]2 • [SbCl3(15-Krone-5)] und [In(12-Krone-4)2] [SbCl6]3· 3 CH3CN / Ionic Crown Ether Complexes of Thallium(I), Lead(II), and Indium(III). Crystal Structures of [T1(12-Crown-4)2][SbCl6], [Pb(15-Crown-5)2] [SbCl6]2 • [SbCl3(15-Crown-5)], and [In(12-Crown-4)2] [SbCl6]3 · 3 CH3CN
Authors: Arnim Henning von , Dehnicke Kurt , Maczek Klaus , Fenske Dieter
Published: March 2015

The ionic crown ether complexes [Tl(12-crown-4)2][SbCl6] (1) and [In(12-crown-4)2][SbCl6]3·3 CH3CN (3) have been prepared by reaction of T1C1 and InCl3, respectively, with SbCl5 in the presence of 12-crown-4 in acetonitrile solution. The lead complex [Pb(15-crown-5)2][SbCl6]2· [SbCl3(15-crown-5)] (2) has been obtained from the reaction of Pb(CH3)2Cl2 with SbCl5 in the presence of 15-crown-5 in acetonitrile solution. 1-3 were characterized by crystal structure determinations.

[Tl(12-crown-4)2][SbCl6] (1): Space group C2/c, Z = 4, 2306 observed unique reflections, R = 0.051. Lattice dimensions at -70°C: a = 2360.9(5), b = 1189.6(2), c = 1080.4(3) pm, β = 111.14(2)°. 1 contains cations [Tl(12-crown-4)2]+, in which the Tl+ ion is coordinated sandwichlike by the eight oxygen atoms of the two crown ether molecules. The lone pair at the thallium ion shows steric activity.

[Pb(15-crown-5)2][SbCl6]2·[SbCl3(15-crown-5)] (2): Space group Pna2(1), Z = 4, 4631 observed unique reflections, R = 0.048. Lattice dimensions at -70°C: a = 2972.5(3), b = 1481.9(5), c = 1305.5(1) pm. 2 consists of [Pb(15-crown-5)2]2+ ions, in which the lead ion is coordinated sandwich-like by the ten oxygen atoms of the two crown ether molecules without steric activity of the lone pair of Pb2+, of SbCl6- ions, and of molecules [SbCl3(15-crown-5)], which are already known.

[In(12-crown-4)2][SbCl6]3·3CH3CN (3): Space group P1̅, Z = 2, 5530 observed unique reflections, R = 0.059. Lattice dimensions at -70°C: a = 1041.8(8), b = 1052(1), c = 1543(2) pm, α = 103.62(9)°, β=108.68(8)°, γ = 99.48(8)°. 3 consists of [In(12-crown-4)2]3+ ions, SbCl6- anions, and crystal CH3CN molecules. The In3+ ion is coordinated sandwich-like by the eight oxygen atoms of the two crown ether molecules, which are disordered in two positions
Zur Struktur von Hydroxy-5-phenyl-furanonen: Lösungs-NMR, Festkörper-13C-NMR und Röntgenstruktur im Vergleich / On the Structure of Hydroxy-5-phenyl-furanone Derivatives: NMR Spectroscopy in Solution and High Resolution Solid State 13C NMR Spectroscopy in Relation to X-Ray Crystallography
Authors: Schmidt M. , Albert K. , Brindle R. , Maichle-Mössmer C. , Eger K.
Published: March 2015

The structure of (5H)-2-Amino-3-hydroxy-5-phenyl-furan-4-one (lb) was determined by NMR-spectroscopy in solution and in the solid state. The structure of its oxidation product, 3,4-Dihydro-3,3,4,4-tetrahydroxy-5-phenyl-furan-2(5H)-one (7), given in the literature as 5-Phenyl-2,3,4-(5H)-furan-trione, was determined by NMR spectroscopy and crystal structure analysis. The solid state NMR spectrum of 7 was compared to the spectrum of dehydroascorbic acid
4,4′-Binaphthylidendione - Farbe und Struktur / 4,4′-Binaphthylidene-1,1′-diones — Colour and Structure
Authors: Kral Andreas , Laatsch Hartmut
Published: March 2015

Synthesis and properties of various 4,4′-binaphthylidene-1,1′-diones are described. The UV spectra of the deep red to purple diones may be calculated on the base of substituent increments. The experimental values of the analyzed substituents can be reproduced using PPP calculations with satisfying accuracy, which makes it possible to predict also absorption maxima of hitherto unknown 4,4′-binaphthylidene-1,1′-diones
Notizen: 13C NMR Spectroscopic Study of Pentacarbonylacetonitrilemetal(0) Complexes of the Group 6 B Elements
Authors: Özkar Saim , Özer Zahide
Published: March 2015

The complexes M(CO)5(CH3CN) (M: Cr, Mo, W) were obtained from the substitution of THF in M(CO)5(THF) which has been generated by photolysis of M(CO)6 in THF and characterized by using IR, 1H NMR and 13C NMR spectroscopies. The acetonitrile ligand is found to be N-bonded to the M(CO)5-moiety with a local C4v-symmetry. The effect of the acetonitrile ligand on the metal-carbonyl bonding was discussed in terms of 13C NMR chemical shifts.
Notizen: Geminal Coupling Constants 2.J(15N13C) in 2-Substituted Pyridines, Measured by Hahn-Echo Extended (HEED) Pulse Sequences
Authors: Wrackmeyer Bernd , Kehr Gerald
Published: March 2015

Coupling constants 2J(15N13CR) and nJ(15N1HR) in 2-substituted pyridines [R = Me (1), CH=CH2 (2), C≡CH (3), C(O)H (4), C(O)Me (5)] have been measured by using Hahn-echo extended (HEED) pulse sequences for one- (1 D) and two-dimensional (2D) 13C/1H NMR (HEED-INEPT, HEED-HETCOR). The magnitude of |2J(15N13CR)| is hardly affected by the hybridization of 13CR. 15N NMR spectra, measured under conditions of ultra high resolution (UHR) confirm the values 2J(15N13CR). 2D 13C/1H HEED-HETCOR experiments show that the sign of 3J(15Ν1HR) is negative in 1, whereas the coupling constants 3J(15N1HR) in 4 and 4J(15N1HR) in 3 have a positive sign
Polydeckerkomplexe mit μ,η5-2,3-Dihydro-1,3-diborolylnickel-Fragmenten als Stapeleinheiten / Polydecker Complexes with μ,η5-2,3-Dihydro-1,3-diborolylnickel Fragments as Stacking Units
Authors: Fenner Ulrich , Kuhlmann Thomas , Brodt Gregor , Roziére Jacques , Siebert Walter
Published: March 2015

Reactions of 2,3-dihydro-1,3-diboroles 6a–h with (C3H5)2Νi lead to µ,η5-2,3-dihydro-1,3-diborolylnickel triple-decker complexes 7a –h. By slow heating these oily, diamagnetic complexes in a rotating flask polycondensation with formation of black 8a–h as well as of bis(allyl)nickel and hexadiene occurs. The latter can be removed under reduced pressure. The constitution of the polymeric material follows from EXAFS studies. The Ni–Ni distance is 3,35 A, the ring atom Ni bonds are in the range of 2,13 to 2,15 A. Thermogravimetric measurements between 200 and 400°C show a mass loss of 20-40%, depending of the alkyl substituents of the heterocycle. In dynamic difference calorimetry an endothermic process occurs near 420°C. The powder conductivity of the amorphous, air-sensitive material is in the range of 10-2 S • cm-1. Doping with iodine or oxygen causes a decrease in the conductivity of these semi-conductors.
Metallkomplexe von Heteroarenen, VII: Bis(2,3,5,6-tetramethyl-η6-pyrazin)vanadium, der erste Bis(aren)metall-Komplex mit vier N-Atomen in der Koordinationssphäre / Metal Complexes of Heteroarenes, VII: Bis(2,3,5,6-tetramethyl-η6-pyrazine)vanadium, the First Bis(arene)metal Complex with Four N Atoms in the Coordination Sphere
Authors: Nowotny Mathias , Elschenbroich Christoph , Behrendt Andreas , Massa Werner , Wocadlo Sigrid
Published: March 2015

Cocondensation of 2,3,5,6-tetramethyl-pyrazine with vanadium atoms affords [2,3,5,6-(CH3)4-η6-1,4-C4N2]2V (6) which has been studied by X-ray crystallography, EPR-spectro-scopy and cyclic voltammetry. As shown by unequal metal ring-atom distances (V—C = 219.6, V—N = 210.9 pm) the ligand in 6 is folded along the N—N axis (dihedral angle 13.6°). The conformation adopted by the cyclic ligands in the crystal has a torsional angle of 44.2° which comes close to the angle of 45° expected for maximum back-bonding, the filled vanadium orbitals 3 dx2-γ2
and 3 dxy interacting separately with unoccupied b3u(π*) orbitals of the individual pyrazine rings. The hyperfine coupling constant a(51V) = 4.45 mT attests to comparatively small spin density at the metal nucleus. It is proposed, that substantial transfer of spin density is effected by V 3dz
2→ag(σn+) overlap, the latter function representing the in-phase combination of the nitrogen “lone pair” orbitals. Contrary to bis(η6-phosphinine)vanadium 8, for the pyrazine complex 6 only the anion 6⁻ is formed reversibly in cyclovoltammetry, oxidation to 6+ being irreversible. However, in common with 8, the redox potentials for 6 show pronounced anodic shifts. Attempts towards η6-coordination of 2,4,6-trimethyl-1,3,5-triazine failed. Apparently, the 1:1 ratio of CH3/N is insufficient to furnish the triazine ring with the appropriate combination of π-donor and δ-acceptor properties essential for synergetic bond formation.
Reaktionen von Komplexliganden, LVI. 3-Pyrrolylcarben-Komplexe des Chroms: Darstellung und neuartige Carbenanellierung zum Isoindol-Gerüst / Reactions of Complex Ligands, LVI. 3-Pyrrolylcarbene Complexes of Chromium: Synthesis and Carbene Annulation to the Isoindole Skeleton
Authors: Dötz Karl Heinz , Glänzer Jörg
Published: March 2015

N-Protected 3-bromo-2,5-dimethylpyrrols, accessible from low-temperature bromination using NBS or BTMABT, have been modified into pentacarbonyl[methoxy(3-pyrrolyl-car-bene)] complexes via sequential halogen/lithium exchange, addition to hexacarbonyl chromium and alkylation. These compounds react with alkynes and amines, resp., to give aminolysis and annulation products. The carbene annulation methodology has been exploited in the synthesis of a persubstituted isoindoloquinone.
On Metal-Modified Nucleobase Triples and Quartets
Authors: Schreiber André , Hillgeris Edda C. , Lippert Bernhard
Published: March 2015

Linking three nucleobases by two metal ions M of linear coordination geometry leads to metal-modified base triples. With M = trans-(amine)2PtII, the bases are forced into an essentially coplanar fashion with interbase H bonding maintained in many cases. The model nucleobase triples described here are of general composition {[trans-(amine)2PtB]2(9-MeA)}n+ with two nucleobases B bound via Pt to N1 and N7 of 9-methyladenine (9-MeA). The X-ray structure of a precursor, ([trans-(CH3H2)2PtCl]2(9-MeA)}(ClO4)2, is briefly described. The generation of metalated, cyclic nucleobase quartets and their expected structures are discussed and ways towards larger macrocyclic metal compounds are pointed out.
Regiospezifische Insertion von [SCN]- und [SeCN]- in die S – C- bzw. Se– C-Bindung Übergangsmetall-koordinierter Thietane und Selenetane
Regiospecific Insertion of [SCN]- and [SeCN]- in the S–C- and Se–C-Bond of Transition-Metal-Coordinated Thietanes and Selenetanes
Authors: Fischer Helmut , Kalbas Claudia , Troll Carsten , Fluck Klaus H.
Published: March 2015

Pentacarbonyl(thietane)tungsten complexes react with thiocyanate, [SCN]-, and SiO2/H2O by insertion of the CN group into a S—C bond of the four-membered heterocycle, 1,3-migration of the pentacarbonyltungsten fragment and protonation of the nitrogen atom to give tungsten-coordinated thiazinthione complexes. Analogously, the reactions of a thietane tungsten complex with [SeCN]- and SiO2/H2O affords a thiazinselone complex. A selenazinthione complex is obtained from a selenetane complex and [SCN]- (+ SiO2/H2O). The insertions are regiospecific and stereoselective. The structure of the trans-isomer of a pentacarbonyl-(thiazinthione) complex has been established by X-ray structure analysis.
Zweikernige Mangan- und Rheniumkomplexe mit gemischt aliphatischen-aromatischen Kohlenwasserstoffbrücken / Dinuclear Manganese and Rhenium Complexes with Mixed Aliphatic-Aromatic Hydrocarbon Bridges
Authors: Lindner Ekkehard , Wassing Walter , Fawzi R. , Steimann M.
Published: March 2015

The symmetrically hydrocarbon-bridged complexes (OC)5M-(CH2)n+1-X-(CH2)n+l-M(CO)5 [n = 1, X = 1,4-C6H4, M = Mn (2a), M = Re (3a); n = 2, X = 1,4-C6H4, M = Mn (2b), M = Re (3b); n = 1, X = 1,3-C6H4, M = Mn (5a), M = Re (6a); n = 2, X = 1,3-C6H4, M = Mn (5b), M = Re (6b); n = 1, X = 1,2-C6H4, M = Mn (8a), M = Re (9a); n = 2, X = 1,2-C6H4, M = Mn (8b), M = Re (9b)] are obtained by the reaction of the bistriflates X[(CH2)„-CH2-OSO2CF3]2 [X = 1,4-C6H4, n = 1 (la), n = 2 (lb); X = 1,3-C6H4, n = 1 (4a), n = 2 (4b); X = 1,2-C6H4, n = 1 (7a), n = 2 (7b)] with the carbonyl metalates [M(CO)5]- (M = Mn, Re) in THF and dimethyl ether, respectively. According to an X-ray structural analysis 8a crystallizes in the triclinic space group P1̅ with Ζ = 2. Depending on the solvent, the reaction of 7 a with [Mn(CO)5]~ affords also the cyclic carbene complex 10a. The behavior of the manganese compounds toward CO has been investigated exemplarily in the case of 8a and leads to the diacyl complex 1,2-C6H4[CH2CH2C(O)Mn(CO)5]2 (11). Upon reaction with Na2CO3/CH3OH 11 is converted to give the corresponding diester 1,2-C6H4[CH2CH2C(O)OCH3]2 (12).
Notizen: CsNaSe — das erste Interalkalimetallchalkogenid mit Cäsium / CsNaSe – the First Inter Alkali Metal Chalkogenide with Cesium
Authors: Sabrowsky Horst , Winter Volker , Feldbaum-Möller Elisabeth , Vogt Petra
Published: March 2015

The grey compound CsNaSe has been prepared. The characterization by X-ray powder methods leads to a tetragonal lattice (P 4/nmm) with a = 499.0(1), c = 808.7(2) pm and Z = 2. The structure is related to the PbFCl structure type.
Rotation Point and KJC Estimations for Miniature CT-Specimens Based on Off-Load Line Displacement
Authors: Valo Matti J. , Planman Tapio K. , Wallin Kim R.
Published: March 2015

In fracture toughness tests, the energy absorbed by the specimen is calculated from load versus load point displacement data. If tests are made with small CT-specimens, direct measurement of load point displacement is often not possible due to small specimen dimensions; subsequently, specimen displacement is measured on the front face of the specimen. The measured displacement is transferred into load point displacement with the help of a geometric rotation point concept. The measurements were performed with miniature CT-specimens of dimensions B = 4 mm, W = 8 mm having the integral clip seated on the specimen front face. The location of the rotation point was concluded from the measured initial compliance by applying the rotation point values of r = 0.5 and r = 0.13 and by comparing the calculated crack lengths with the measured crack lengths. The value of r = 0.5 was observed to be too high and the value r = 0.13 produced the measured crack lengths accurately. A linear combination of elastic and plastic deformations is proposed to be used for calculating the location of the rotation point outside the elastic loading range. The load line load–displacement curves were derived and the measured KJC-values were calculated with the assumptions r = 0.5 and with the linear combination described in the paper. The linear combination believed to be more relevant than the value r = 0.5 resulted in lower KJC-values than r = 0.5. However, the difference was only about 1.6 % in KJC-values, which changes the T0 values approximately by 1°C. Hence, the measured KJC-values are not sensitive to the exact location of the rotation point used in the analysis.