bluuebunny/crossref_metadata_2025 huggingface dataset:
35Cl NQR and X-Ray Studies of Hexachloropalladates A2PdCl6 (A = Rb, Cs, NH4) and the Cl2 – Clathrates Bis(tetramethylammonium)hexachloropalladate (Me4N)2PdCl6 · Cl2 and Bis(tetramethylammonium)hexachlorostannate (Me4N)2SnCl6 · Cl2
Authors: Storck Peter , Weiss Alarich
Published: March 2015

The 35Cl NQR frequencies of A2PdCl6 were studied. For A = (CH3)4N+ a clathrate [(CH3)4N]2PdCl6 · Cl2 was found and its crystal structure was determined (Fd3 c, Z = 32, a = 2554.5 pm, R = 0.062). The clathrate [(CH3)4N]2SnCl6 · Cl2 was prepared, too. It is isomorphous with the corresponding palladium salt. The results of the 35Cl NQR studies are discussed on the basis of the crystal structure.
Hochdrucksynthese und Strukturverfeinerung von SrVO3, Sr2VO4 und Sr3V2O7 / High-Pressure Synthesis and Structure Refinement of SrVO3, Sr2VO4, and Sr3V2O7
Authors: Range Klaus-Jürgen , Rau Franz , Klement Ulrich
Published: March 2015

Single crystals of SrVO3, Sr2VO4 and Sr3V2O7 have been obtained by high-pressure reactions in a modified belt-type apparatus. The crystal structures, refined from diffractometer data, are as follows: SrVO3, perovskite type, Pm3̄m, a = 3.8408(3) Å, R = 0.017, Rw = 0.018, composition from occupancy refinement of oxygen positions SrVO2.93(2); Sr2VO4, K2NiF4 type, I 4/mmm, a = 3.837(1), c = 12.569(1) Å, R = 0.014, Rw = 0.017; Sr3V2O7, Sr3Ti2O7 type, I 4/mmm, a = 3.839(1), c = 20.262(2) Å, R = 0.020, Rw = 0.029.
Diorganobismutacetylide / Diorganobismuthacetylides
Authors: Rudolph Klemens , Wieber Markus
Published: March 2015

Diorganobismuthacetylides R2BiC≡CR′ (R = C6H5, p-CH3C6H4, CH3; R′ = CH3, C(CH3)3, C6H5) were prepared by reactions of R2BiBr with NaC=CR' in liquid ammonia. Reaction of two equivalents of NaC≡CR′ with RBiBr2 leads to mixtures of R2BiC=CR′ and RBi(C=CR′)2.
Metall-Ν,N′-bis(trimethylsilyl)benzamidinate: Synthese und Kristallstruktur von Bis[N,N′-bis(trimethylsilyl)benzamidinato]chrom(II), [PhC(NSiMe3)2]2Cr / Metal-N,N′-bis(trimethylsilyl)benzamidinates: Synthesis and Crystal Structure of Bis[N,N′-bis(trimethylsilyl)benzamidinato]chromium(II), [PhC(NSiMe3)2]2Cr
Authors: Buijink Jan-Karel , Noltemeyer Mathias , Edelmann Frank T.
Published: March 2015

The preparation of N,N′-bis(trimethylsilyl)benzamidinates of chromium, manganese, zinc and bismuth is described. The chromium(II) derivative [PhC(NSiMe3)2]2Cr (2) has been characterized by an X-ray structure determination. Treatment of CpTiCl3 with one equivalent of Na[PhC(NSiMe3)2] · 0.5 Et2O yields the mixed Cp/benzamidinate complex [PhC(NSiMe3)2]CpTiCl2 (9).
Synthesis and Molecular Structure of Disulfane
Authors: Hahn Josef , Schmidt Petra , Reinartz Klaus , Behrend Jörg , Winnewisser Gisbert , Yamada Koichi M. T.
Published: March 2015

The synthesis and structure of disulfane are presented. Pure disulfane, H2S2, has been obtained by the cracking distillation of raw sulfane mixtures in a rotary evaporator, thus substituting the classical cracking column for the rotating flask of the evaporator. Pure, gaseous dideuterodisulfane could be generated by the solvolysis of bis(methyldiphenylsilyl)disulfane, (MePh2Si)2S2, with D2O in the presence of trichloroacetic acid as stabilizing agent. Partially deuterated disulfane has been prepared by H,D exchange between pure H2S2 and DCl. For the first time the molecular structure of HSSH has been determined based solely on microwave spectroscopy with the following parameters: r(SS) = 2.0564 A, r(SH) = 1.3421 A, dihedral angle γ = 90.34°, and <(SSH) = 97.88°.
Cyclopentadienyl-, Indenyl- und Trifluormethylcyclopentadienyl-Cobalt-Komplexe mit Akzeptor-substituierten Olefinen als Liganden / Cyclopentadienyl, Indenyl and Trifluoromethylcyclopentadienyl Cobalt Complexes with Acceptor-Substituted Olefins as Ligands
Authors: Werner Helmut , Mahr Joachim
Published: March 2015

The complexes C5H5Co(PMe3)2 (1), C9H7Co(PMe3)2 (2) and (C5H4CF3)Co(PMe3)2 (3) react with mono- and disubstituted ethenes such as styrene, acrylic acid methylester, methylvinylketone, acroleine, acrylic acid amide, acrylonitrile, maleic anhydride, maleic and fumaric acid dimethylester, and fumaric dinitrile to give the olefin(phosphane)cobalt compounds (ring)Co(PMe3)(olefin) (4-32) in good to excellent yields. With acrylonitrile, two different rotamers are obtained which indicates that there is a considerable energy barrier for rotation around the metal-olefin bond. The reactions of 1 and 3 with maleic acid dimethylester (MDE) lead not only to the formation of the expected products (ring)Co(PMe3)(MDE) (22, 23) but also to the thermodynamically favored isomers (ring)Co(PMe3)(FDE) (24, 26) containing fumaric acid dimethylester (FDE) as ligand. A similar isomerization has been observed upon treatment of 2 and 3 with fumaric dinitrile (FDN) which gives besides the complexes (ring)Co(PMe3)(FDN) (29, 31) also the maleic dinitrile (MDN) derivatives (ring)Co(PMe3)(MDN) (30, 32). The olefin(trimethylphosphane)cobalt compounds are surprisingly inert and neither on photolysis nor on heating give the isomeric hydrido(vinyl)metal complexes.
Photochemische Reaktionen von Übergangsmetall-Organyl-Komplexen mit Olefnen, VI. Reaktionen von Tricarbonyl-η5-2,4-cyclohexadienyl-mangan mit konjugierten Dienen / Photochemical Reactions of Transition Metal Organyl Complexes with Olefins, VI. Reactions of Tricarbonyl (η5-2,4-cyclohexadienyl)manganese with Conjugated Dienes
Authors: Kreiter Cornelius G. , Lehr Klaus
Published: March 2015

Tricarbonyl-η5-2,4-cyclohexadien-1-yl-manganese (1) was reacted photochemically at 253 K with simple conjugated dienes. Four different types of products were obtained, depending upon the dienes. With 1,3-butadiene (A) dicarbonyl-η4:3-1-(3-buten-1,2-diyl)-2,4-cyclohexadiene-manganese (2A) is isolated. 2-Methyl-1,3-butadiene (B) yields the methyl-substituted diastereomeric dicarbonyls 2B, 2B′, the [4+5]-cycloadduct tricarbonyl-η3:2-3-methyl-bicyclo-[4.3.1]-3,8-decadien-7-yl-manganese (3B) and tetracarbonyl-η3-4-methylene-bicyclo[4.3.1]-8-decen-3-yl-manganese (4B) with an exocyclically coordinated tetracarbonylmanganese fragment. With 2,3-dimethyl-1,3-butadiene (C) only the [4+5]-cycloadduct 3C and the tetracarbonyl 4C are obtained. No CC-bond formation is observed with E,E-2,4-hexadiene (D) and 1,3-cyclohexadiene (E). Carbonyl-η5-2,4-cyclohexadien-1 -yl-η4-E,E-2,4-hexadiene-manganese (5D), and carbonyl-η4-1,3-cyclohexadiene-η5-2,4-cyclohexadien-1-yl-manganese (5E) are the only products. The complexes were separated and purified by HPL chromatography. Their constitutions were determined by IR and NMR spectroscopy.
Übergangsmetallkomplexe mit Schwefelliganden, LXX. / Transition Metal Complexes with Sulfur Ligands, LXX.
Authors: Sellmann Dieter , Seubert Bernd , Knoch Falk , Moll Matthias
Published: March 2015

In order to study specific properties of transition metal sulfur complexes, reactions of [Mo(NO)2(′S4′)] (1) with nucleophiles were investigated. With sodiumborohydride or hydrazine, 1 yields the hydroxylaminyl complex [Mo(η2-NH2O)(NO)(′S4′)] (2). 2 crystallizes from DMF as 2 · DMF whose molecular structure was determined by X-ray structure analysis (P21/c, Z = 4, a = 1204.4(3), b = 1579.7(4), c = 1253.0(4) pm, β = 117.44(2)°, R = 0,056, Rw = 0,040). The Mo centre is coordinated by two trans thiolato S, two cis thioether S atoms, the co-ligand NO and side-on NH2O in a distorted pentagonal bipyramid; the DMF molecule is hydrogen bonded to the NH2O-ligand. NMR spectroscopy shows that in solution 2 exists in two configurational isomers differing in the orientation of the side-on NH2O with respect to the [Mo(NO)(′S4′)] core. The mechanism of the reduction of 1 is discussed in terms of a 2e--2H+-transfer.
Neue (Ether-Phosphan)-Liganden mit unterschiedlichen elektronischen und sterischen Eigenschaften / New (Ether-Phosphine) Ligands with Different Electronic and Steric Properties
Authors: Lindner Ekkehard , Dettinger Johannes , Möckel Andrea
Published: March 2015

New ether-phosphines of the type Ph2P~D (2d, 2g-1, 2n-p) with different electronic and steric properties which are provided with open-chained or cyclic ether moieties are obtained by reaction of LiPPh2 with the corresponding chloromethyl substituted ethers ClCH2~D (1d, 1g-1, 1n-p) in THF. The ligands 2d, 2g-1, and 2n-p are characterized by selected IR and NMR data which function as probes for complexation to transition metals.
Schwefelverbrückte Metallocen/Aluminium-Verbindungen - Isolierung und dynamisches Verhalten von [(MeCp)2ZrS]2 · AlMe3 / Sulfur-Bridged Metallocene/Aluminum Complexes - Isolation and Dynamic Behaviour of [(MeCp)2ZrS]2 · AlMe3
Authors: Erker Gerhard , Albrecht Markus , Psiorz Christian
Published: March 2015

The reaction of cyclodimeric group 4b metallocene sulfides [(RCp)2MS]2 (M = Zr, R = H, Me, tBu: 2a-c; M = Hf, R = H, Me: 2d,e) with trialkylaluminum compounds gives dimeric sulfur-bridged metallocene/aluminum complexes [(RCp)2M(R′)SAlR′2]2 (M = Zr, R = H, Me, tBu, R′ = Me: 3a-c; M = Hf, R = H, Me, R′ = Me: 3d,e, R′ = Et: 3f,g). At low temperature the primarily formed adduct [(MeCp)2ZrS]2 · AlMe3 6 was isolated and its temperature-de-pendent dynamic NMR spectra monitored. The metallocene sulfide/trialkylaluminum addition products exhibit a reaction pattern which indicates the occurrence of reversible alkyl migration between the main group and transition metal center. This may be of relevance for developing novel types of olefin oligomerization catalysts.
Trichlorsilylierung sperriger Dialkylchlorphosphane und Tetraalkyldiphosphane mit Hexachlordisilan / Trichlorosilylation of Bulky Dialkylchlorophosphanes and Tetraalkyldiphosphanes with Hexachlorodisilane
Authors: Martens Reiner , Mont Wolf-Walther du , Lange Lutz
Published: March 2015

Chlorodiisopropylphosphane reacts with hexachlorodisilane to give diisopropyl(trichlorosilyl)phosphane which reacts with the educt chlorophosphane to produce tetraisopropyldiphosphane. Tetraisopropyldiphosphane reacts with hexachlorodisilane to provide diisopropyl(trichlorosilyl)phosphane. With di-tert-butylchlorophosphane and tetra-tert-butyldiphosphane, the corresponding reactions leading to di-tert-butyl(trichlorosilyl)phosphane are much slower; while the product does not react further with di-tert-butylchlorophosphane, it does with chlorodiisopropylphosphane. A stable 1:1 complex is formed from di-tert-butyl(trichlorosilylphosphane) with silver bromide. Products are characterized on the basis of analytical and 1H, 13C, 29Si and 31P NMR data.
Zur Kristallchemie von Supersäuren: Bildung und Struktur der tiefschmelzenden Addukte SbF5 · CF3SO3H und SbF5 · 7 HF [1] / Crystal Chemistry of Superacids: Formation and Structure of the Low-Melting Adducts SbF5 · CF3SO3H and SbF5 · 7 HF [1]
Authors: Mootz Dietrich , Bartmann Klemens
Published: March 2015

The melting diagram of the superacid system SbF5—CF3SO3H as well as of SbF5—HF has been studied by DTA and the crystal structure of one newly found low-melting adduct in each case determined. The adduct SbF5 · CF3SO3H (m.p. — 1°C, monoclinic, space group P21/c, Z = 4 formula units per unit cell) is composed of complex molecules F5SbOS(CF3)(O)OH which are linked by strong hydrogen bonds O-H ···F to infinite chains. The adduct SbF5 · 7HF (melting incongruently at —75°C, monoclinic, I 2/m, Z = 2) is a fluoronium salt, (H7F6)SbF6. The novel H7F6
+ cation is formed as an unbranched chain by very strong hydrogen bonds between the respective F atoms, which become weaker from the center to the ends. A further hydrogen bond of this kind, between the cations and the octahedral SbF6- anions, again leads to a one-dimensional polymer.
Schwingungsspektren und Kraftkonstanten des Anions [BN2]3- in Li3BN2, Ca3B2N4 und Ba3B2N4 / Vibrational Spectra and Force Constants of the Anion [BN2]3- in Li3BN2, Ca3B2N4 and Ba3B2N4
Authors: Somer Mehmet
Published: March 2015

Vibrational spectra of the title compounds have been measured and assigned based on the symmetry D∞h of linear [BN,]3- units. The (B–N) force constants and bond orders have been calculated and compared with those of isoelectronic molecules and ions.
Spectroscopic Characterization of the Selenium-Rich Heterocycles Se5S, Se7S, and 1,5-Se6S2
Authors: Steudel Ralf , Papavassiliou Maria , Baumgart Frank
Published: March 2015

Se5S in CS2 solution at 20°C spontaneously decomposes to give a mixture of 8 selenium-rich cyclic molecules which have been identified by reversed-phase HPLC and 77Se NMR spectroscopy as Se6, Se7, Se8, Se6S, Se7S, 1,2-Se6S2, 1,5-Se6S2, and 1,4-Se4S2. NMR spectra of Se5S, Se7S, and 1,5-Se6S2 have been measured for the first time; Raman spectra of solid Se5S and Se7S as well as crystal data of Se7S are reported in addition. A mechanism based on nucleophilic attack on Se5S is proposed for the formation of the products.
Einfluß der Enolisierung auf die Reduktion von β Ketocarbonsäure-Derivaten mit Zinkborhydrid / Influence of the Enol Formation on the Reduction of β-Keto Carboxylic Acid Derivatives by Zinc Borohydride
Authors: Meier Herbert , Krause Volker
Published: March 2015

Depending on the keto-enol equilibrium 1 ⇄ 2 reduction of the esters and the amides 1/2 a—g with Zn(BH4)2/ZnCl2 attacks either at the CO or at the CO2R group. A high diastereoselectivity (98:2 or more) is observed for the formation of the β-hydroxy compounds 3a,b,c,e,f in favour of the erythro forms. As to the structure determination of 3, different steric effects and different intramolecular hydrogen bonding have to be considered, leading to different rotameric populations.
Notizen: Synthesis of (±)-(10-2H, 11-2H2, 12-2H3)Jasmonic Acid
Authors: Miersch Otto
Published: March 2015

(±)-(10-2H, 11-2H2, 12-2H3)Jasmonic acid has been synthesized starting from racemic jasmonic acid via 2-formylmethyl-3-methoxycarbonylmethylcyclopentanone by reaction with (1-2H, 2-2H2, 3-2H3)propylidene-triphenylphosphoran followed by sponification of the labelled methyl jasmonate.
Kationenleiter auf der Basis von Poly(maleinsäure) / Cation Conductors Based on Polymaleic Acid
Authors: Fritz H. P. , Bertelmann R.
Published: March 2015

Maleic anhydride (MA) was polymerized by a free radical mechanism (PMA) and transformed into the poly-acid and its alkali salts, the ionic conductivities of which were determined. Blends of the lithium salt with propylene carbonate (PC), low molecular weight poly(ethyleneglycol) (PEG), and some crown ethers show improved conductivities. Alkali alcoholates and alcohols react with PMA to form linear poly(methylesters), comb-shaped polymers with methoxy poly(ethyleneoxide) pendants, and PEG cross-linked structures. Alkalisalt/ester copolymers as well as LiClO4 podand complexes were studied. Among these, the viscous comb-shaped polymers show the highest conductivities, when having a Li : O ratio of 1:2.7, i.e. x = 10-5S/cm at 20°C and 4 · 10-3S/cm at 80°C.
Adsorption of Tetrammine-carbonato and -cis-diaqua and Triethylenetetramine-carbonato and -cis-diaqua Complexes of Cobalt(III) on Titanium Dioxide as Models for the Binding of Uranyl Ions from the Tricarbonatouranyl Complex Ion
Authors: Lauerer Brigitte , Pusch A. , Stadler K. H. , Boehm H. P.
Published: March 2015

The adsorption of several cobalt(III) complex ions with carbonato or two aqua ligands in cis-position (and related complexes) was studied with the objective of a comparison with the adsorption of UO2
2+ ions from [UO2(CO3)3]4- solutions. One CO3
2- group per adsorbed UO2
2+ ion was found on the TiO2 surface after vacuum-drying at room temperature. Pre-adsorption of HPO4
2- ions resulted in an increased UO2
2+ uptake, whilst coverage of the TiO2 surface with adsorbed Al hydroxo complexes resulted in the opposite effect. The adsorption rate as well as the saturation uptake were higher for the cis-[Co(NH3)4(H2O)2]3+ complex than for [Co(NH3)4(CO3)]+. The diffuse reflectance spectra are similar for both adsorbates. Also with cis-[Co(trien)(H2O)2]3+ and [Co(trien)(CO3)]+ the diaqua is more rapidly adsorbed, whereas the saturation values are very similar. No carbonate is found in the adsorbates with both carbonato complexes, the ammine or trien ligands are retained on the adsorbed CoIII ions, however. Temperature-programmed decomposition spectra showed that the bonding of the ammine ligands is weakened in the adsorbed complexes compared to bulk salts of the complex ions. It is concluded that the metal complexes are anchored to the TiO2 surface by bonding to two surface oxygen ions.
Synthese und Eigenschaften von 1,2,7,3,6-Thiadiazadiborepinen, Kristallstruktur des 2,7-Di-tert-butyl-3,6-dimethyl-3,6-dihydrobenzo-1,2,7,3,6-thiadiazadiborepins / Syntheses and Properties of 1,2,7,3,6-Thiadiazadiborepines, Crystal Structure of 2,7-Di-tert-butyl-3,6-dimethyl-3,6-dihydrobenzo-1,2,7,3,6-thiadiazadiborepin
Authors: Habben Carl D. , Heine, Andreas , Stalke Dietmar , Sheldrick George M.
Published: March 2015

2,5-Bisdimethylamino-2,5-dihydrobenzo[b]-1,2,5-thiadiborole (2) has been obtained from the diiodine-derivative by reaction with dimethyl-aminotrimethylsilane. Reaction of 2 or 2,5-bisdimethylamino-1′,2′-dimethyl-2,5-dihydrobenzo[b]-thiadiborole with di-tert-butyl-, tertbutyl-trimethylsilyl- and bistrimethylsilyl-sulfurdiimide yields the 2,7,3,6-tetrahydrobenzo[b]-1,2,7,3,6-thiadiazadiborepines (3a-3e). 1H, 11B, 13C NMR, MS and analytical data and results of analysis are given. For 3a the X-ray structure is reported.
Addition von Schwefeldioxid an Ruthenium-Thiolat-Komplexe, Struktur eines bemerkenswert stabilen Thiolat-SO2-Addukts [1]/ Addition of Sulfur Dioxide to Ruthenium Thiolate Complexes, Structure of a Remarkably Stable Thiolate-SO2-Addukt [1]
Authors: Schenk Wolfdieter A. , Dombrowski Eberhard , Reuther Irene , Stur Thomas
Published: March 2015

Ruthenium thiolates [cpRu(PPh3),(SMe)] and [cp*Ru(PPh2Me)2(SR)] (R = Me, Ph) react with sulfur dioxide in two different ways, substitution of phosphine for SO2, and addition of SO2 to the thiolate ligand. The structure of [cpRu(CO)(PPh3)(SMe · SO2)] was determined by X-ray crystallography: Crystals are monoclinic, space group P21/n, a = 10.26(9), b = 16.00(6), c = 14.73(6) Å, β = 90.141(5)°, Ζ = 4. The most remarkable feature is a very long (247,8 pm) S—S single bond. [cp*Ru(PPh2Me)(SO2)(SPh)] and the corresponding sulfur monoxide complex [cp*Ru(PPh2Me)(SO)(SPh)] undergo [3+2] cycloaddition with dimethylacetylene-dicarboxylate.
Übergangsmetallkomplexe mit Schwefelliganden, LXXXVI. Säure-Base- und Redox-Reaktionen von [Ni(′MeS2′)2] mit H+, PMe3, NO+ und NO. Röntgenstrukturanalyse von [Ni(PMe3)(′MeS2′)2] (′MeS2′ = o-(Methylthio)thiophenolat(1–)) / Transition-Metal Complexes with Sulfur Ligands, LXXXVI. Acid-Base and Redox Reactions of [Ni(′MeS2')2] with H+, PMe3, NO+ and NO. X-Ray Structure Determination of [Ni(PMe3)(′MeS2′)2] (′MeS2′ = o-(methylthio)thiophenolate(1–))
Authors: Sellmann Dieter , Schillinger Helmut , Knoch Falk
Published: March 2015

In order to elucidate specific properties of nickel-sulfur complexes, addition and substitution reactions of [Ni(′MeS2′)2] (1) were investigated. 1 is rapidly hydrolyzed by aqueous HCl yielding ′MeS2′–H and Ni(II) ions. 1 coordinates phosphines as coligands, thioether donors decoordinate, however, simultaneously. The monophosphine complex [Ni(PMe3)(′MeS2′ )2] (2) was characterized by X-ray structure determination. It contains a square-planar NiS3P unit and one decoordinated thioether group. Redox reactions of 1 occur with NO+ and NO, yielding the binuclear nitrosyl complexes cis- and trans-[Ni(NO)(′MeS2′)]2 (3) and the disulfide [′MeS2']2•
Natrium-tetraethylammonium-tetrasulfid, Na+NEt4
+S4
2−. Synthese und Kristallstruktur / Sodium Tetraethylammonium Tetrasulfide, Na+NEt4
+S4
2−. Synthesis and Crystal Structure
Authors: Sens Irina , Bacher Alfred Dirk , Müller Ulrich
Published: March 2015

NaNEt4S4 was obtained from an equimolar solution of Na2S4 and NEt4Cl in ethanol. Its crystal structure was determined by X-ray diffraction with 4175 observed unique reflexions, R = 0.044. Crystal data: a = 713.4(4), b = 1744.5(9), c = 1204.0(5) pm, β = 105.8(3)°, space group P21/n, Ζ = 4. In the structure, chains consisting of Na+ and S4
2− ions run in the a direction, every Na+ being coordinated by four terminal S atoms of S4
2− ions (two terminal, one chelating). The chains are separated by the NEt4
+ ions.
Zur Chemie der Proto-und allo-Proto-lichesterinsäure / Contribution to the Chemistry of Proto- and allo-Proto-lichesterinic Acids
Authors: Huneck Siegfried , Takeda Reiji
Published: March 2015

The isolation and spectroscopic characterization of (-)-allo-proto-lichesterinic acid from Cetraria komarovii is described. Proto-lichesterinic and allo-proto-lichesterinic acids are transformed into numerous nitrogen-containing derivatives and the isomerization of the dihydro acids is investigated.
Tetrafluorcyclodi- und Hexafluorcyclotrisilazane / Tetrafluorocyclodi- and Hexafluorocyclotrisilazanes
Authors: Tecklenburg Brigitte , Klingebiel Uwe , Noltemeyer Mathias , Schmidt-Bäse Dieter
Published: March 2015

Bis(silylamino)difluorosilanes (1,2) are prepared in the reaction of lithiated di-tert-butylmethyl- and tert-butyl-dimethylsilylamine with tetrafluorosilane. The dilithium derivative of 1 reacts with SiF4 to give the tetrafluoro-substituted four-membered (Si-N) ring system [(CMe3)2MeSiN-SiF2]2 (3). Two four-membered rings [(RN-SiF2)2 (4), (RN-SiFNRSiF3)2 (5), R=CMe3SiMe2] are obtained in the reaction of dilithiated 2 with SiF4. The dilithiated silylamines and SiF4 also react with formation of 3 and 4. However, besides 4 the six-membered ring (CMe3SiMe2N-SiF2)3(6) is obtained. Crystal structures of 3,5, and 6 were determined. A transannular Si ··· Si ring distance of 237,5 pm is found in 3.
2-(4-Toluenesulphonyl)-3-aryloxaziridines as Oxidizing Reagents for P(III) Compounds
Authors: Klein Manuela , Ugi Ivar
Published: March 2015

The preparation of four 2-(4-toluenesulphonyl)-3-aryloxaziridines by oxidation of the corresponding imines by peracids is described. The relative oxidation rates of trimethyl phosphite by these oxaziridines are determined.
Synthesis and NMR Studies of Some Steroidal Isoxazoles
Authors: Giacopello Sergio , Deluca Mónica E. , Seldes Alicia M.
Published: March 2015

A short synthesis of 17α-pregna-2,4-dien-[2,3-d]isoxazol-17β-ol (1) is described using mild reaction conditions and with a high overall yield. The equilibrium between keto-enolic forms has been studied by 1H NMR methods. Complete assignments of all the resonances in the 1H and 13C NMR spectra of Danazol have been made using a variety of one and two-dimensional correlation methods. 13C NMR spectra of all the intermediate and related model compounds were also assigned.
Synthese und Antitumoraktivität von [1,2-Diamino-1-(p-hydroxy)benzyl]ethan(dichloro)platin(II)-Komplexen
Synthesis and Antitumor Activity of [1,2-Diamino-1-(p-hydroxy)benzyl]ethane(dichloro)platinum(II) Complexes
Authors: Brunner Henri , Maiterth Friedrich , Treittinger Barbara
Published: March 2015

The complexes [1,2-diamino-l-(p-hydroxy)benzyl-1-(methyl, ethyl, and phenyl)]ethane-(dichloro)platinum(II) were synthesized and characterized. The benzylic p-hydroxy group of the 1,2-diaminoethane ligand leads to good water-solubility of the complexes. The ligands were synthesized in a Strecker-type reaction, starting from the corresponding p-methoxybenzylketones. The amino nitriles were reduced to the diamines. Finally, the p-methoxy groups were converted into hydroxy groups by ether cleavage. For the preparation of the complexes, K2PtCl4 was added to the ligands. The antitumor activity of the platinum(II) compounds was tested towards the human mammary carcinoma cell line MDA-MB 231. The antitumor effect depends on the substituents and increases in the series phenyl, methyl, and ethyl. As a maximum, a growth inhibition value of 77% was obtained.
Über die thermische Zersetzung von N2H6[CrF5(H2O)] und die neue Verbindung N2H6CrF5 / On the Thermal Decomposition of N2H6[CrF5(H2O)] and the New Compound N2H6CrF5
Authors: Bentrup Ursula
Published: March 2015

Thermal decomposition of N2H6[CrF5(H2O)] has been investigated by thermoanalytical, X-ray and IR spectroscopic methods. Under quasi-isobaric conditions the decomposition takes place in several steps. The intermediate N2H6CrF5 has been found which crystallizes monoclinically with α = 555.0 pm, b = 1084.6 pm, c = 777.0 pm, β = 91.76°. N2H6CrF5 decomposes via an amorphous intermediate to give pure rhomboedrical CrF3 as the final product. One of the intermediate has been identified as chromium fluoride ammoniate CrF3 0.4 NH3. No hydrolysis reactions have been observed.
Neue metallorganisch substituierte Bismut-Chalkogen-Verbindungen mit Mo2BiE-Gerüst (E = S, Se) / New Organometallic Bismuth Chalcogen Compounds with Mo2BiE Framework (E = S, Se)
Authors: Merzweiler Kurt , Brands Ludwig
Published: March 2015

[{Cp(CO)3Mo}2BiCl] 1 reacts with silylated chalcogens E(SiMe3)2 (E = S, Se) to give the compounds [{Cp(CO)2Mo}2EBiCl] (E = Se 2, S 3). The structures of 2 and 3 were determined by X-ray crystallography. In the solid state two [{Cp(CO)2Mo}2EBiCl] units are linked by two Bi—Cl—Bi bridges to form the dimer [{Cp(CO)2Mo}2EBiCl]2 with a planar Bi2Cl2 ring. The [{Cp(CO)2Mo}2EBiCl] units contain distorted Mo2BiE tetrahedra.
Zum Einfluß von Substituenten auf σ-π-Wechselwirkung: Winkelverzerrungen in C-Borylmethylenboranen / Effect of Substituents on σ-π-Interaction: Distortion of Angles in C-Borylmethyleneboranes
Authors: Willershausen Peter , Höfner Andrea , Allwohn Jürgen , Pilz Monika , Massa Werner , Berndt Armin
Published: March 2015

C-Borylmethyleneboranes with one or two O-Aryl substituents in the boryl group, 3 a and 4b, are obtained by cleavage of B–C single bonds in the presence of a B–C double bond. The duryl(methyl)borylmethyleneborane 7 is formed by thermal rearrangement of the vinylborane 5a. 4b has an almost normal B–C– B angle (118.3(7)°) and the most strongly deshielded dicoordinated boron atom (δ11B = 80) observed so far for methyleneboranes. This indicates weak C–B hyperconjugation in 4b. The distorted B–C– B angles in 3a (108.8(5)°) and 7 (98.1(5)°) and the shielded dicoordinated boron atom of 7 (δ11B = 63) in spite of its positivation by π-π delocalization demonstrate an increase of C–B hyperconjugation upon decrease of electronegativity of substituents in the boryl group.
A Facile Synthesis of Isopongaflavone, Atalantoflavone Dimethylether, Racemoflavone Dimethylether and their Analogues
Authors: Vijayalakshmi C. S. , Rajendra Prasad K. J.
Published: March 2015

A convenient route to pyranoflavones (natural and synthetic) from acetyl hydroxy chromans via the corresponding dihydro analogues by the use of Claisen condensation in the key step is reported.
Die Phasendiagramme der Systeme aus Dibromdimethylsilan und 2-, 3- oder 4-Methylpyridin / The Phase Diagrams of Systems Containing Dibromodimethylsilane and 2-, 3- or 4-Methylpyridine
Authors: Hensen Karl , Grebner Jürgen
Published: March 2015

By analyzing the DSC heating curves and the resulting phase diagrams of the systems of dibromodimethylsilane and 2-, 3- or 4-methylpyridine the existence of the congruently melting addition compounds ((CH3)2SiBr2)2 · (3-methylpyridine) and (CH3)2SiBr2 · (4-methylpyridine)2, and the incongruently melting addition compounds ((CH3)2SiBr2)2 · (2-methylpyridine) and ((CH3)2SiBr2)2 · (4-methylpyridine) could be proved.
Übergangsmetall-substituierte Diphosphene, XXVI Zum Einfluß des Ringliganden auf Bildungstendenz und Stabilität von Diphosphenyleisenkomplexen des Typs (η5-C5R5)(CO)2Fe-P= P-Mes (Mes = 2,4,6-tBu3C6H2). Röntgenstrukturanalyse von (η5-C5Me4Et)(CO)2Fe-P(SiMe3)2 / Transition Metal Substituted Diphosphenes, XXVI Investigations on the Influence of the Ring Ligand upon Formation and Stability of Diphosphenyl Complexes (η5-C5R5)(CO)2Fe-P=P-Mes (Mes = 2,4,6-tBu3C6H2). X-Ray Analysis of (η5-C5Me4Et)(CO)2Fe-P(SiMe3)2
Authors: Weber Lothar , Schumann Iris , Stammler Hans-Georg , Neumann Beate
Published: March 2015

The disilylphosphido iron complexes (η5-C5R5)(CO)2Fe-P(SiMe3)2 (1b–d) result from the reaction of the corresponding bromo compounds (η5-C5R5)(CO)2FeBr with LiP(SiMe3)2 · 2 THF. The complexes 2b–d are cleanly converted into the diphosphenyl complexes (η5-C5R5)(CO)2Fe-P=P-Mes* (2b–d) by treatment with equimolar amounts of Mes*PCl2. The products 1b–d and 2b–d have been characterized by elemental analysis as well as spectroscopic data (IR, 1H, 13C, 31P NMR, MS). The molecular structure of η5-C5Me4Et)(CO)2Fe-P(SiMe3)2 (1b) has been established by single-crystal X-ray analysis.
Synthese und Struktur von Nb0,89Fe0,93Te2 und Ta0,77Fe0,90Te2 / Synthesis and Structure of Nb0.89Fe0.93Te2 and Ta0.77Fe0.90Te2
Authors: Neuhausen Jörg , Stork Karl-Ludwig , Potthoff Elisabeth , Tremel Wolfgang
Published: March 2015

Nb0.89Fe0.93Te2 and Ta0.77Fe0.90Te2 were prepared by chemical transport reactions. The crystal structures of both compounds were determined using X-ray single crystal methods. The structures of the layer compounds Nb0.89Fe0.93Te2 (Pmna, Z = 2, a = 7.951(1) Å, b = 7.241(1) A, c = 6.233(1) Å) and Ta0.77Fe0.90Te2 (Pmna, Z = 2, a = 7.890(2) Å, b = 7.252(2) Å, c = 6.192(1) Å) are based on a hexagonal close packing of Te atoms. Approximately one-half of the octahedral holes in this packing are occupied by Nb (Ta) atoms, about one-quarter of the tetrahedral holes are occupied by Fe atoms. The relationship to the NiAs structure type is discussed.
Tetramethylcyclopentadienylindium(I) und Tetramethylcyclopentadienylthallium(I): Synthese, Charakterisierung und Röntgenstrukturanalyse / Tetramethylcyclopentadienylindium(I) and Tetramethylcyclopentadienylthallium(I): Synthesis, Characterization and X-Ray Structural Analysis
Authors: Schumann Herbert , Kucht Homa , Kucht Andreas , Görlitz Frank H. , Dietrich Andreas
Published: March 2015

Tetramethylcyclopentadienyllithium was reacted with InCl to form [C5HMe4]In (1). [C5HMeJTl (2) was prepared from tetramethylcyclopentadiene and T1OC2H5. The 1H and 13C NMR spectra of the new compounds as well as the X-ray crystal structures of the polymeric metallocenes 1 and 2 are reported and discussed in relation to the structures of other cyclopentadienylindium(I) and -thallium(I) compounds.
Die Kristallstruktur von α-ΚΖnΡΟ4 / The Crystal Structure of α-KZnPO4
Authors: Andratschke Martina , Range Klaus-Jürgen , Haase Heinz , Klement Ulrich
Published: March 2015

Single crystals of a-KZnPO4, the low-temperature modification of potassium zinc orthophosphate, were obtained from KZnPO4 powder by high pressure experiments in a modified Belt-type apparatus. The crystals are hexagonal, space group P 63, with a = 18.155(2), c = 8.504(1) Å, c/a = 0.4684 and Z = 24. The crystal structure, refined from diffractometer data to R = 0.077, Rw = 0.068, comprises an ordered network of ZnO4 and PO4 tetrahedra with rings of six tetrahedra vertical to the c-axis. The potassium ions are located in cavities formed by the rings.
Gold(I) Complexes of Secondary and Tertiary Amines. Crystal Structure of Triphenylphosphineaurio(I)qinuclidinium Tetrafluoroborate
Authors: Grohmann Andreas , Riede Jürgen , Schmidbaur Hubert
Published: March 2015

The secondary amine piperidine and the tertiary amine quinuclidine (l-azabicyclo[2.2.2]-octane) were reacted in THF with one equivalent of triphenylphosphinegold(I) tetrafluoroborate, [Ph3PAu]+ BF4
-, to give the monoaurated ammonium salts of formula [RnNH(3-n)AuPPh3]+ BF4
- (n = 2, 3). The compounds were obtained as crystalline solids in good yields, and were characterized by IR and NMR spectroscopy as well as mass spectrometry and elemental analysis. The crystal structure of the quinuclidinium salt was determined (space group Pbca, Z = 8). The analysis shows independent formula units with no intermolecular Au • • • Au contacts. The Au(I)– N bond (2.11(1) A) is significantly longer than the average value found in poly-aurated ammonium salts.
Darstellung und Struktur von Ν,N′-Dimethylepindolidion / Preparation and Structure of Ν,N′-Dimethylepindolidione
Authors: Polborn Kurt , Lechner Günther , Wagner Hans-Ulrich , Gompper Rudolf , Schmidt Christoph , Beck Wolfgang
Published: March 2015

Methylation of epindolidione gives the Ν,N′-dimethyl derivative which was characterized by X-ray diffraction.

Dibenzo[b,g][1,5]naphthyridin-6,12(5,11 H)-dione (Epindolidione) [1] sind Strukturisomere des Indigos. Die geringe Löslichkeit sowie - ähnlich wie in Indigo [2] - die tiefe Lage der NH-und CO-Valenzschwingungen von Epindolidion ist auf intermolekulare Wasserstoffbrücken zurückzuführen. Obwohl Epindolidion nur gelb ist, wurde die Verbindung von Lüttke und Klessinger als indigoider Farbstoff eingestuft [3]. In letzter Zeit fanden Epindolidione als potentielle Halbleiter [4] sowie für den Einbau in Peptide Beachtung [5]. Im Rahmen von Arbeiten über Naphthyridin-Derivate [6] sowie über Metallkomplexe von Farbstoffen [7] interessierte die Alkylierung bzw. Metallierung (Isolobal-Analogie [8]) von Epindolidion, die am N- oder (und) O-Atom erfolgen kann.
Improvement in 13C NMR Measurements of Ring-Substituted η5-Cyclopentadienyl Metal Complexes
Authors: Wrackmeyer Bernd , Biersack Martin , Brendel Hans-Dieter , Herberhold Max
Published: March 2015

z1.5 Time-consuming 13C NMR measurements of sparingly soluble ring-substituted cyclopentadienyl metal complexes can be avoided if INEPT techniques are applied. In particular, polarization transfer based on long range 13C—1H couplings (nJ(13C1H); n = 2, 3) can be used to observe 13C NMR signals of quaternary 13C nuclei, which are difficult to observe in normal 13C NMR spectra. The improvement in the signal-to-noise ratio enabled to observe satellites due to 77Se- 13C and 125Te—13C couplings. Some typical ferrocene derivatives as well as η5-cyclopentadienyl-manganese- and -rhenium tricarbonyl derivatives were selected to demonstrate that the recommended methods are independent of the metal and of the type of ring substitution.
Die Kristallstrukturen der Palladium(II)-Komplexe [Pd(CH3CN)4](BF4)2, [PdCl(μ2 -PPh2)(HPPh2)]2 · CH2Cl2 und [PdCl(HPPh2) {H(OPPh2)2}] / The Crystal Structures of the Palladium(II) Complexes [Pd(CH3CN)4](BF4)2, [PdCl(μ2-PPh2)(HPPh2)] · CH2Cl2, and [PdCl(HPPh2){H(OPPh2)2}]
Authors: Gebauer Thorsten , Frenzen Gerlinde , Dehnicke Kurt
Published: March 2015

The crystal structures of the title compounds were solved by X-ray methods.

[Pd(CH3CN)4](BF4)2: Space group Pbca, Z = 4,812 observed unique reflections, R = 0.057, wR = 0.033. Lattice dimensions at -80 °C: α = 1027.5(5), b = 1242.8(6), c = 1280.3(6) pm. The compound consists of planar [Pd(CH3CN)4]2+ ions with Pd-N bond lengths of 195.6 pm and BF4
- anions.

[PdCl(μ2-PPh2(HPPh2)]2 • CH2Cl2 crystallizes in two polymorphic forms in the same space group type but with different cell parameters, which depends on the conditions of the synthesis. α-form: Space group P21/c, Z = 4, 4680 observed unique reflections, R = 0.041, wR = 0.033. Lattice dimensions at -80 °C: a = 937.2(2), b = 1750.3(6), c = 1593.9(5) pm, β = 106.32(2)°. β-form: Space group Ρ21/n, Ζ = 4, 2519 observed unique reflections, R = 0.105, wR = 0.067. Lattice dimensions at -80 °C: a = 1118.0(4), b = 1222.4(3), c = 1849.9(4) pm, β = 90.72(2)°. Both polymorphs contain centrosymmetric molecules [PdCl μ2- PPh2)(HPPh2)]2 with Pd-P bond lengths of 226.6 pm for the bridging PPh2 groups and Pd-P bond lengths of 232.2 pm for the terminal HPPh2 ligands.

[PdCl(HPPh2){H(OPPh2)2}]: Space group Pbca, Z = 8,3673 observed unique reflections, R = 0.038, wR = 0.032. Lattice dimensions at -80 °C: a = 1736.6(3), b = 1874.4(4), c = 1983.1(4) pm. The palladium atom has planar coordination consisting of the chlorine atom, the phosphorus atom of the HPPh2 ligand (Pd-P bond length 235.5 pm), and by the two phosphorus atoms of the H(OPPh2)2 chelate (Pd-P bond lengths 225.9 and 231.0 pm).
Photochemistry in Porous Materials, II / Photolysis of Benzoin Ethers in Silicalite
Authors: Dasmohapatra Gourkrishna , Wolff Thomas , Bünau Günther von
Published: March 2015

Four benzoin ethers 1 (a: methyl-, b: ethyl-, c: isopropyl-, d: phenylether) were photolyzed inside the channel system of silicalite S- 115, a novel type of zeolite. Products which could be separated from the zeolite framework in various relative yields were pinacol ethers (from a, b, c), benzil (a–d), benzaldehyde (a–d), benzoates (a–d), and phenol (d). While the former three types of products clearly arise from Norrish type I cleavage of the parent molecules, a mechanism involving the enolic form of the benzoin ethers is proposed in order to explain the formation of benzoates and phenol.
Tetramethylthioharnstoff als Ligand in Übergangsmetallkomplexen: Redoxsubstitutionen mit dem Dithiobis(1,1,3,3-tetramethylformamidinium)-Kation Synthese und Kristallstrukturen von [Fe(SR)L3]+BPh4
-, [FeL4]2+BPh4
-)2 und [RuCl2(CO)2L2] (R = 2,4,6-i-Pr3C6H2; L = SC(NMe2)2) / Tetramethylthiourea as Ligand in Transition Metal Complexes:. Redox Substitution Reactions with the Dithiobis(1,1,3,3-tetramethylformamidinium) Cation Synthesis and Crystal Structures of [Fe(SR)L3]+BPh4
-, [FeL4]2+(BPh4
-)2 and [RuCl2(CO)2L2] (R = 2,4,6-i-Pr3C6H2; L = SC(NMe2)2)
Authors: Bierbach Ulrich , Barklage Walter , Saak Wolfgang , Pohl Siegfried
Published: March 2015

The oxidation of tetramethylthiourea (SC(NMe2)2,L) with HC1/H2O2 yields dithiobis-(1,1,3,3-tetramethylformamidinium)dichloride, [{SC(NMe2)2}2]2+Cl2 (1). Anions in 1 can be easily exchanged by tetraphenylborate to give [{SC(NMe2)2}2]2+(BPh4
-)2 (2).

The reaction of the neutral complex [Fe(SR)2L2] (3) (R = 2,4,6-i-Pr3C6H2) with 2 results in either partial or complete oxidation of the thiolate ligands, depending on the stoichiometric ratio of the reactants, and replacement by neutral ligands L. The cations [Fe(SR)L3]+ and [FeL
4]2+ were isolated as tetraphenylborate salts (4 and 5, respectively).

[RuCl2(CO)2L2] (6) was obtained by the reaction of dodecacarbonyltriruthenium with 1. In the course of the reaction ruthenium is oxidized and CO ligands are partially replaced by L and Cl-.

The structures of 4, 5 and 6 were determined from single crystal X-ray diffraction data.

4: monoclinic, P 21/n, a = 2272.1(2), b = 1009.1(1), c = 2533.4(2) pm, β = 96.96(1)°. V = 5765· 106 pm3, Z = 4, conventional R = 0.066. The cation of 4 shows a distorted tetrahedral coordination of Fe(II) with Fe–Sthiolate 229.0(2) pm and Fe–Sthiourea 237.6(2) pm (mean).

5: monoclinic, P 21/n, a = 1153.2(1), b = 2913.8(1), c = 2019.1(1) pm, β = 92.84°. V = 6776.5 • 106 pm3, Z = 4, conventional R = 0.061. The cation of 5 possesses approximate D2d symmetry with the central [FeS4] tetrahedron compressed along the two-fold axis (Fe–S: 234.2 pm (mean)).

6: orthorhombic, P bcn, a = 847.9(2), b = 1442.2(3), c = 1660.1(3) pm. V = 2030.0· 106 pm3, Z = 4, conventional R = 0.037. The neutral complex cis, cis, trans-6 exhibits a distorted octahedral coordination of Ru(II) with thiourea ligands in trans position. 6 possesses C2 symmetry. The S–Ru–Sa angle was found to be 165.0°. The deviation from linearity is probably caused by the sterically hindered tetramethylthiourea ligands. The Ru–S bond length is 241.6(1) pm.

Structural studies of geometrical parameters in tmtu complexes that are related to the nature of the M–Sthiourea bond suggest, that 1,1,3,3-tetramethylthiourea (L) does not only function as a σ-donor but possibly also exhibits weak π-donor and π-acceptor properties, respectively. The exact type of bonding is determined by the nature and oxidation state of the metal centre.
Cyclohex-2-en-l-ones in Heterocyclic Synthesis: Facile Synthesis of 5,6-Dihydrocoumarins, their Thio Analogues and their Corresponding Dehydrogenated Derivatives
Authors: Nawwar G. A. M. , Haggag B. M. , Yakout El-S. M. À.
Published: March 2015

Novel synthesis of 5,6-dihydrocoumarins, their thioanalogues and their corresponding dehydrogenated derivatives utilizing substituted cyclohex-2-en-1-ones as starting components is reported.
Bildung von Arsensäure aus [As2Cl8]2Ionen und Ozon. Die Kristallstruktur von PPh4Cl · H3AsO4 / Formation of Arsenic Acid from [As2Cl8]2- Ions and Ozone. Crystal Structure of PPh4Cl · H3AsO4
Authors: Ruhlandt-Senge Karin , Bacher Alfred-Dirk , Müller Ulrich
Published: March 2015

Reaction of ozone with (PPh4)2[As2Cl8] in CH2C12 at low temperatures yields a red compound, possibly an ozonide. Upon evaporation of the solvent at –78 °C the ozone is released again. At -40 °C or above a subsequent reaction yields PPh4[AsCl6], PPh4Cl · H3AsO4, and other products. The crystal structure of PPh4Cl · H3AsO3 was determined by X-ray diffraction (4253 observed reflexions, R = 0.031). It is triclinic, space group P1̅, and consists of H3AsO4 molecules joined to dimer units via H bridges and associated via O–H · · · Cl- bridges to strands. The packing of the PPh4
+ ions is discussed. Products of the reaction of (PPh4)2[Sb2Cl8] with ozone in CH2C12 are PPh4[SbCl6] and (PPh4)2[SbOCl4]2 · 2 CH2Cl2.
(Dichloro)-μ-(1,3,5-trithian)kupfer(II), [CuCl2 · C3H6S3]n]n und (Dichloro)-(1,4,7-trithiacyclononan)kupfer(II), [CuCl2 · C6H12S3] / (Dichloro)-μ-(1,3,5-trithiane)copper(II), [CuCl2· C3H6S3]n, and (Dichloro)-(1,4,7-trithiacyclononane)copper(II), [CuCl2· C6H12S3]
Authors: Shen Jing , Pickardt Joachim
Published: March 2015

Reactions of CuCl2 with 1.3.5-trithiane and 1.4.7-trithiacyclononane yield crystals of CuCl2· C3H6S3, and CuCl2• C6H12S3, resp. According to X-ray structure analyses, CuCl2• C3H6S3 forms infinite chains, whereas CuCl2• C6H12S3 consists of discrete molecules. In CuCl2• C3H6S3 the thioether molecules act as bridging ligands. Each Cu is coordinated to two S atoms belonging to two adjacent ligands, and to two Cl atoms; thus a distorted square planar coordination results. In CuCl2· C6H12S3 the Cu is penta-coordinated to the three S atoms of the ligand and to two Cl atoms. One Cu–S bond is significantly longer than the two others; the coordination polyhedron may be regarded as a distorted tetragonal pyramid.
9,10-Dinaphthylphenanthrene: Synthese, Rotationsisomerie und Photocyclisierung zu polycyclischen aromatischen Kohlenwasserstoffen
9,10-Dinaphthylphenanthrenes: Synthesis, Rotational Isomers and Photocyclization to Polycyclic Aromatic Hydrocarbons
Authors: Gundermann Karl-Dietrich , Romahn Elke , Zander Maximilian
Published: March 2015

9,10-Di(1-naphthyl)phenanthrene (5 a) and 9,10-di(2-naphthyl)phenanthrene (5 b) have been synthesized. It is shown that 5 a and 5b both form two stable rotational (cis/trans) isomers with the naphthalene molecular planes perpendicular to the phenanthrene plane. In the case of 5 a the mixture of the two isomers has been separated in a preparative scale and each isomer characterized by e. g., NMR spectroscopy. Photocyclization of 5a leads to benzo[e]phenanthro[1,2,3,4-ghi]perylene (9) while 5 b yields phenanthro[9,10-i]pentahelicene (14); both hydrocarbons have not been previously described in the literature. The observed selectivities of photocyclization are explained on the basis of the structures and stabilities of the initially formed photoproducts (dihydro structures 15 and 14 a). The role of intramolecular non-radiative singlet-singlet energy transfer (naphthalene → phenanthrene) as competing with photocyclization is discussed in detail.
Chromium(III) Complexes with Some Optically Active α-Hydroxy Acids
Authors: El-Shahawi M. S. , El-Bindary A. A.
Published: March 2015

Complexes obtained from CrCl3Py3 with some optically active α-hydroxy acids have been characterized by elemental analysis, magnetic susceptibility, vibrational (IR), electronic and circular dichroism (CD) spectra. The magnetic susceptibility data are close to the spin-only value for a d3 chromium(III) ion in octahedral or distorted octahedral symmetry. Three (Cr—Cl) vibrational modes in the region 410-290 cm-1 are observed for some of the complexes indicating C2ν, local symmetry of ligand atoms around the chromium(III). In the electronic spectra two peaks are observed in the range 16949-18018 and 22986-24570 cm-1. They are assigned to d—d transitions in pseudo octahedral symmetry. The structure of the complexes is likely to be facial since strong and well defined Cotton effects are observed. The parameters (Dq, B, β35) for the complexes provide reassurance that pyridine nitrogen is preserved.
On the Chemistry of Resiniferonol. I. Preparation of Resiniferonol, Synthesis of Homologous Aliphatic Resiniferonol-9,13,14-orthoesters and Some of their Bioactivities
Authors: Adolf W. , Hecker E.
Published: March 2015

The preparation of the daphnane prototype polyfunctional diterpene resiniferonol from resiniferatoxin (1) contained in latex from Euphorbia unispina or E. poisonii was modified to convert in an `early’ fraction of the acetone extract the extremely irritant 1 to the much less irritant 9,13,14-ortho(phenylacetate) 2 by transesterification. 2 was obtained in good yields and can be handled conveniently to prepare resiniferonol as reported previously. By esterification of resiniferonol with homologous straight chain aliphatic acids from C2 to C18 resiniferonol-14,20-diacylates were prepared. Treatment of the diacylates with perchloric acid/methanol yielded by intramolecular formation of the orthoester function the corresponding 9,13,14-orthoester-20-acylates. They were cleaved selectively by base catalysed transesterification to obtain the resiniferonol-9,13,14-orthoacetate (3), -hexanoate (4), -decanoate (5), -tetradecanoate (6) and -octadecanoate (7). On the mouse ear, unexpectedly they exhibit only weak irritant activity and on the mouse back skin practically no tumor promoting activity.
Notizen: Single-Crystal Structure Refinement of LiZnAs
Authors: Hönle Wolfgang
Published: March 2015

The crystal structure of LiZnAs has been verified with single crystal X-ray methods. LiZnAs crystallizes in a filled-up zinc blende type of structure (F 43 m, a = 593.9(1) pm, As at site 4a (000); Zn at site 4d (3/4 3/4 3/4); Li at site 4 c (1/4 1/4 1/4); 25 hkl; R = 0.018). As is coordinated by 4 Li and 4 Zn atoms with identical distances of 257.2(1) pm. Li and Zn atoms are tetrahedrally coordinated by As. No indications for a disorder between Li and Zn have been found.
Notizen: Preparation and Structure of Tris(acetylacetonato)silicon Dichloroargentate
Authors: Högerle Dietlinde , Link Ulrich , Thewalt Ulf
Published: March 2015

The ionic compound [Si(acac)3][AgCl2] · CH2C12, (1) was synthesized by reaction of [Si(acac)3][HCl2] and silver acetate in dichloromethane. A singlecrystal X-ray analysis shows that the cation has an octahedral tris-chelate structure and that the anion is a polymeric chain, composed of edgesharing AgCl4 tetrahedra.
Offene und geschlossene P-funktionalisierte Diferriophosphonium-Salze des Typs [ { CpFe(CO)2}2P(Ph)R]+ X⁻ bzw. [ {μ-CO(CpFeCO)2} P(Ph)R]+ X⁻ / Open and Closed P-Functionalized Diferriophosphonium Salts of the Type [{CpFe(CO)2}2P(Ph)R]+ X⁻ and [{ μ-CO(CpFeCO)2}P(Ph)R]+ X⁻
Authors: Klasen Christian , Effinger Guido , Schmid Siegbert , Lorenz Ingo-Peter
Published: March 2015

The reaction of Ph(R)PSiMe3 with an excess of CpFe(CO)2Cl results in the elimination of Me3SiCl to give the open diferriophosphonium halides [{CpFe(CO)2}2P(Ph)R]Cl (R = H, Ph, CH2SiMe3, Me) (1 a—d). The deprotonation reaction of 1 a with KOBut at —78°C results in the formation of the unstable diferriophosphane {CpFe(CO)2}2PPh (3), which reacts with alkylating reagents RX (R = Me, CH2Ph, CH2COOEt; X = Cl, I) to give the P-functionalized diferriophosphonium halides [{CpFe(CO)2}2P(Ph)R]X (1 d’—f). The light-sensitive compounds 1b—f are found to eliminate readily a CO ligand upon photolysis to give the corresponding closed P-functionalized diferriophosphonium salts [{µ-CO(CpFeCO)2}P(Ph)R]X (2b—f) with a bridging CO ligand and a Fe— Fe bond. The mass, IR and NMR spectra of 1, 2 and the results of a crystal structure determination of [{μ-CO(CpFeCO)2}PPh2]BPh4 (2b’) are reported and discussed.