Showing papers in "Zeitschrift für Naturforschung B in 1982"

Zweikernige und dreikernige Carbonyleisenkomplexe mit 1.2-und 1.3-Dithiolatobrückenliganden / Dinuclear and Trinuclear Carbonyliron Complexes Containing 1,2-and 1,3-Dithiolato Bridging Ligands

Abstract: The reactions of 1,2- and 1,3-dithioles, HSRSH, with Fo₃(CO)₁₂ give the dinuclear compounds Fe₂(CO)₆(SRS) in good yields. With R = C₂H₄ or R = C₃H₆ the trinuclear compounds (CO)₃Fe(SRS)Fe(CO)(SRS)Fe(CO)₃ containing an open Fe₃ chain are obtained.

Röntgenograpliische und magnetische Untersuchungen an perowskitverwandten Cyanoverbindungen CsMIIMIII(CN)6 / X-Ray and Magnetic Studies of Perovskite-Related Cyano Compounds CsMIIMIII (CN)6

Abstract: Abstract The perovskite-related cyano compounds CsMIICr(CN)6 (MII = Mn, Zn), CsZnFe(CN)6 and CsMnCo(CN)6 (Mn = Mn-Cu) are characterized by their IR active C - N and MIII-CN stretching frequencies, their lattice constants and their magnetic susceptibilities (4,2-295 K). Except for CsCuCo(CN)6, which is tetragonally distorted, all compounds crystallize cubically face-centered (with lattice constants in the range from 1020 to 1084 pm). The magnetic behaviour indicates low spin MIII and high spin MII states, supporting the IR evidence for a strictly ordered MIII-CN-MII arrangement. The compound CsMnCr(CN)6 is ferrimagnetic, with a Néel temperature of TN = 90 K and an extrapolated spontaneous magnetization of a = 2,30 μB at 0 K. Superexchange interactions via the cyano bridges are considered responsible for the ferrimagnetism observed.

Cyclische Diazastannylene, XVI [1]. Ringe und Käfige mit Ge(II), Sn(II) und Pb(II) / Cyclic Diazastannylenes, XVI [1]. Rings and Cages with Ge(II), Sn(II) and Pb(II)

Abstract: 1,3-Di-tert-butyl-2,2-dimethyl-1,3,2,4λ2-diazasilagermetidine (1) and its lead analogue (3), which have been synthesized from the dichlorides of germanium and lead and the dilithium salt of bis(tert-butylamino)dimetliylsilane, are compared with the corresponding tin compound 2 in their reactivity towards tert-butylamino. There is a clear dependence of the reaction rate on the nature of the element. The norcubane-like cage Ge3(NtBu)4H2 (5 a) and the cubane-like cages Ge4(NtBu)4 (6a) and Pb4(NtBu)4 (6c) result from these reactions. When 3 is treated with bis(methylamino)dimethylsilane, [(Me2Si)2(MeN)3Pb]n (7) precipitates from the reaction mixture. Sn3(NtBu)4H2 (5b) can be transformed into Sn3(NtBu)4Ge (8a) and Sn3(NtBu)4Pb (8b) when heated at high temperatures with 1 or 3, respectively. In these polycyclic compounds two low-valent elements of group IV are simultaneously present in one cage unit. As can be shown, 8b is less stable to bond cleavage than 8a and undergoes redistribution reactions at elevated temperatures to form Sn4(NtBu)4 (6b), Sn2Pb2(NtBu)4 (9). SnPb3(NtBu)4 (10) and Pb4(NtBu)4 (6c).

Der Einfluß von Atropisomerie und chiralem Zentrum auf die biologische Aktivität des Metolachlor / The Influence of Atropisomerism and Chiral Centre on the Biological Activity of Metolachlor

Abstract: The four stereoisomers of the grass herbicide Metolachlor, the isomerism of which is based on a combination of a chiral centre and a chiral axis, were prepared, and their absolute configurations determined by X-ray analysis. The synthesis was achieved by using optically active starting materials and new optically active carbamates as intermediates. The herbicidal activity is mainly influenced by the chiral centre, the S-isomers being the most active ones.

The Crystal Structure of Carbonyl Gold(I) Chloride, (OC)AuCl

Abstract: The crystal structure of (OC)AuCl has been determined and refined to R 0.037 (space group Cmcm, a = 407.1(1), b = 1042.2(4), c = 532.1(3) pm, Z =4). The structure consists of discrete, exactly linear molecules; all atoms lie on the special positions 0, y, 1/4. The bond lengths involving the light atoms are affected by libration. The shortest Au ··· Au contacts between molecules are 338 pm.

Tetraalky lammonium - tetr achlor oantimonate (III). Struktur und Schwingungsspektren / Tetraalky lammonium Tetrachloroantimonates(III). Structure and Vibrational Spectra

Abstract: The crystal and molecular structures of tetraethyl- (1), tetra-η-propyl- (2) and tetra-nbutylammonium tetrachloroantimonate(III) (3) were determined by X-ray analysis. There are discrete Sb4Cl164- (1) and Sb2Cl82- (2 and 3) anions. The Sb-Cl bond lengths vary in the range between 234 and 326 pm, and are explained as in a three centre-four electron situation. The vibrational spectra of the anions are briefly discussed

Bi2, das Bismuth-Homologe des Distickstoffs als Komplexligand in Bi2[W(CO)5]3 / Bi2, the Bismuth Homologue of Dinitrogen as a Ligand in Bi2[W(CO)5]3

Abstract: Reductive dehalogenation of BiCl₃ with Na₂W₂(CO)₁₀ leads to Bi₂[W(CO)₅]₃ (1), which contains an axial Bi₂ ligand side-on coordinated to three W(CO)₅ groups. The star-type arrangement of three metal carbonyl moieties around a Bi₂ axis with a very short Bi-Bi bond distance (281.8(3) pm) and a Bi₂W₃ core of approximate D₃ₕ symmetry is proved by an X-ray analysis (R₁ = 0.041). 1 is thus the highest homologue of a series of complexes X₂[W(CO)₅]₃ (X = As, Sb, Bi) and is the first stable molecular compound to contain a Bi₂ ligand.

Kristallstrukturen der selenid- bzw. sulfidverbrückten Gold(I)verbindungen [Se(AuPPh3)+3]PF6- und [S(AuPPh3)2] · CH2Cl2/Crystal Structures of the Selenide- and Sulphide-Bridged Gold(I) Complexes [Se(AuPPh3)3]+PF6- and [S(AuPPh3)2] · CH2Cl2

Abstract: Abstract The Compound [S(AUPPh3)2] · CH2Cl2 was prepared from Ph3PAuCl and H2S in CH2Cl2 and characterised by X-ray structure determination [P21/c, a = 1851.6(4), b = 2225.1(6), c = 880.3(2) pm, β = 96.32(1)°, Z = 4, R = 0.053]. A constrained refinement of the light atom positions was necessary because of pseudosymmetry. Ph3PAuPF6 reacts with Se(Sn)(CH3)3)2 to give [Se(AuPPh3)3]+PF6- which was also characterised by X-ray methods [P1̄, a = 1539.5(6), b = 1800.5(7), c = 2289.5(9) pm, α = 89.35(3), β = 72.44(3), γ = 69.75(3)°, Z = 4, R = 0.061]. There are two formula units in the asymmetric unit. Both structures show short Au···Au contacts (ca. 300-340 pm).

An Investigation of AlCl3 Solutions in Ethers by 27Al NMR Spectroscopy

Abstract: Abstract 27Al NMR studies of AlCl3 solutions in diethyl ether reveal the presence of AlCl4 at high concentrations. This ion can also be recognized besides AlCl3·OR2 at low temperature in dilute solutions, while at 25 °C a single signal is observed, which represents the average of all species in solution. More extensive dissociation of AlCl3 results in tetrahydrofuran. The main species in equilibrium with one another are AlCl3·2THF, AlCl-4 and AlCl2(THF)+2. Nearly quantitative dissociation to yield AlCl-4 and [AlClL5]2+ occurs in dilute solutions of AlCl3 in monoglyme (L reprents one oxygen donor atom); at higher concentration an adduct AlCl3·L with Al in a tetrahedral environment is also present. This trend towards extensive dissociation is also observed in the solutions of AlCl3 in diglyme and triglyme. Relative peak areas are in agreement with the formation of a 1:1 electrolyte [AlCl2L4]+AlCl-4 in diglyme, whereas additional dissociation into [AlClL5]2+ and AlCl-4 occurs in triglyme.

Die Struktur des Na7Ga13-I und ein Konzept zur bindungsmäßigen Deutung / The Structure of Na7Ga13-I and its Characterization by a Bonding Scheme

Abstract: The new compound Na₇Ga₁₃-I crystallizes in the trigonal-rhombohedral system, space group R3m, with the constants a = 14965(3) pm, c = 3893(1) pm, c/o = 260 The Ga atoms form Ga₁₂ icosahedra and Ga₁₅ clusters, connected to a threedimensional net The arrangement of these clusters is related to the MgCu₂ structure The Na content of this compound correlates with the number of electrons necessary for a stable electron configuration in the Ga partial structure The BaAl₄ type structure of NaGa₄ has been confirmed by single crystal data

The Principle of Minimum Chemical Distance and the Principle of Minimum Structure Change

Abstract: The principle of minimum chemical distance (PMCD) is derived from the general theory of the BE- and R-matrices, and makes precise the vague classical “principle of minimum structure change”. In fact, the PMCD may be seen as the principle of minimum structure change in mathematical terms. It provides a quantitative measure of chemical similarity of isomeric molecular systems. Its applications lie in the fields of correlations of substructures, elucidation of reaction mechanisms, and evaluation of synthetic pathways as is illustrated by examples. The mathematical foundations of the computer assisted application of the PMCD are presented.

Zur Chemie des Ingenols, II [1] Ester des Ingenols und des ⊿7.8 -Isoingenols / On the Chemistry of Ingenol, II [1] Esters of Ingenol and ⊿7.8 -Isoingenol

Abstract: Abstract Preparation and purification of 3-acylates of ingenol (1a) structurally related to naturally occuring, irritant and cocarcinogenic principles are described. It is shown that 3-acylates partly rearrange to corresponding 5-acylates when they are chromatographecl. From the 3-acylates or from ingenol (1a) a mixed and a symmetric ingenol-3,20-diacylate is synthesized respectively. Ingenol-5,20-acetonide (2a) is rearranged to its ⊿7.8-isomer 3b. Starting with 3b ⊿7.8-isoingenol (3a) and the 3-tetradecanoate of ⊿7.8-isoingenol (3d) are prepared. Most of the ingenol derivatives prepared are tested for their irritant activity on the mouse ear.

Metallkomplexe mit Tetrapyrrol-Liganden, XXVIII. Mononukleare Nitridomangan(V)-Porphyrine: die ersten Mangan-Stickstoff-Dreifachbindungen/ Metal Complexes with Tetrapyrrole Ligands, XXVIII. Mononuclear Nitridomanganese(V) Porphyrins: the First Manganese Nitrogen Triple Bonds

Abstract: Abstract The first complexes containing a manganese-nitrogen triple bond, nitrido(octaethylporphinato) manganese(V) [MnN(OEP)]** and nitrido[meso-tetra(p-tolyl)porphinato]manganese( V) [MnN(TTP)], are prepared by hypochlorite oxidation of the corresponding methoxomanganese( III) porphyrins, Mn(OEP)OMe and Mn(TTP)OMe, in the presence of ammonia. The red, pentacoordinated, diamagnetic species are identified by UV/VIS-, IR-, 1H NMR, and mass spectra. While the isoelectronic oxochromium(IV) or oxomolybdenum( IV) porphyrins behave as weak oxidants or reductants, respectively, the nitridomanganese( V) unit in the square pyramidal environment is chemically remarkably stable.

Synthese und Struktur von [CpFe(CO)2SO2]+ AsF6- / Synthesis and Structure of [CpFe(CO)2SO2]+ AsF6–

Abstract: Abstract The cationic sulfur dioxide complexes [CpFe(CO)2SO2]+AsF6- (7) and [CpCr(NO)2SO2]+AsF6- (9) are obtained in almost quantitative yield from CpFe(CO)2I(CpCr(NO)2Cl) and AgAsF6 in liquid SO2. With excess transition metal halide dinuclear halogen-bridged cations ([CpFe(CO)2IFe(CO)2Cp]+ and [CpCr(NO)2ClCr(NO)2Cp]+) are formed. The crystal structure of 7 is reported, and the bonding in the complexes is discussed in the light of spectroscopic data.

Kristall- und Molekülstruktur von „Imido-tetraphenyl-dithiophosphinsäure" und Imido - tetraphenyl- diphosphinsäure / Crystal and Molecular Structure of "Imido-tetraphenyl-dithio-phosphinic Acid" and Imido-tetraphenyl-diphosphinic Acid

Abstract: The crystal structures of the title compounds have been investigated in order to gain information on the problem of tautomerism associated with these and related compounds. [Ph₂P(S)]₂NH crystallizes in the triclinic space group P 1. Its structure is represented by the above formula, e.g. as a disubstituted amine with its nitrogen atom being sp²-hybridized. In contrast, ,,[Ph₂P(O)]₂NH" in the solid state is present as its tautomer Ph₂P(O)-N = PPh₂OH. It is an imidodiphosphinic acid as previously suggested. The crystals are monoclinic, space group P 2₁/n, Z - 2. Crystallographic inversion centers are occupied by the N- and the unique H-atom. Therefore a linear PNP arrangement as well as a symmetric OH-O-hydrogen bridge are characteristic for the structure of this molecule. The short PN bonds suggest a high bond order approaching 2. A consequence of the hydrogen bonded oxygen atoms are fairly long PO distances. The crystal structure of is made up of infinite zig-zag chains of Ph2P(0)NPPh2OH molecules along the crystals b-axis

Beiträge zur Chemie des Phosphors, 116 Kernresonanzspektren und Kristallstruktur von Tri-tert-butylcyclotriphosphan / Contributions to the Chemistry of Phosphorus, 116 NMR Spectra and Crystal Structure of Tri-tert-butylcyclotriphosphane

Abstract: A complete analysis of the ³¹P, ¹³C and ¹H NMR spectra of tri-tert-butyl-cyclotriphosphane (1) was carried out and the resulting NMR parameters were correlated with the X-ray data of the molecule. It was found, that increasing P-P-C-bond angles correspond to a downfield shift and an increase of the absolute values of the negative ¹J(PP) and ¹J(PC) coupling constants. Generally, the chemical shifts of cyclotriphosphanes as well as of larger cyclic phosphanes depend on the endo- and exocyclic bond angles, the dihedral angle between the electron lone pairs of adjacent P-atoms, and the β-effect. On the basis of the X-ray and chemical shift data of 1, the bond angles of other cyclotriphosphanes can be deduced from their δ(³¹P) values. 1 crystallizes triclinically in the space group P1 with Z = 4 formula units. The X-ray analysis confirms the NMR-spectroscopically determined three-membered ring structure with the tert-butyl substituents on either side of the ring plane. Due to steric hindrance between the two tert-butyl groups in cis position, the corresponding P-P-C-bond angles show the largest values so far observed for organylcyclophosphanes.

Effects of Through-Conjugation on the Molecular Structure of p-Nitroaniline [1]

Abstract: Abstract A new X-ray diffraction study of p-nitroaniline shows that through-conjugation has highly significant effects on the geometry of the molecule, as compared to aniline and p-nitrobenzoic acid. The effects include a moderate decrease of the internal angles of the ring at substituted carbons, with respect to values derived by superimposing independent angular distortions from each substituent.

Röntgenstrukturbestimmung von AlCl3-Pyridin-Addukten: Der strukturelle Aufbau im trans-Dichlorotetrakis(pyridin)aluminium(III)- Tetrachloroaluminat(III) und im Trichlorotris(pyridin)aluminium(III) / X-ray Diffraction Study of AICl3-Pyridine Adducts: The Crystal Structure of trans-Dichlorotetrakis(pyridine)aluminium(III)tetrachloroaluminat(III) and of Trichlorotris(pyridine)aluminium(III)

Abstract: Abstract Crystals of [Al(C5H5N)4Cl2][AlCl4] are orthorhombic, Pna21, Z = 4, a = 18.522(7), b = 15.141(5), c = 9.593(3) Å, V = 2690(2) Å3 , Dc = 1.440 g/cm3 . The structure has been solved from 5968 diffractometer measured intensities and refined by full-matrix least squares to Rw(F) = 0.032. The crystal structure shows the complex to be trans-dichloro-tetrakis(pyridine)aluminium(III) tetrachloroaluminat(III). The mean trans Al-Cl-and trans Al-N-distances in the octahedron are 2.279(3) and 2.070(4) Å, respectively. Crystals of Al(C5H5N)3Cl3 are monoclinic, P21/c, Z = 4, a = 7.261(2), b = 29.961(4), c = 8.624(1) Å, β = 98.12(2)°, V -1857(1) Å3 , DC = 1.326 g/cm3 . The structure has been solved from 4707 diffractometer measured intensities and refined to Rw(F) = 0.028. The crystal structure shows octahedral complexes AlCl3·3 (C5H5N) with trans geometry. The Al-N-distance trans to chlorine (2.096(2) Å) is significantly longer than the two other Al-N-distances (mean 2.072(2) Å).

Zintlphasen mit komplexen Anionen: Zur Kenntnis von Ca3AlAs3 und Ba3AlSb3/Zintl Phases with Complex Anions: On Ca3AlAs3 and Ba3AlSb3

Abstract: The new compound Ca3AlAs3 crystallizes in the orthorhombic system (space group: Pnma) with a = 1221.2(3) pm, b = 420.1(2) pm, c = 1343.4(4) pm. In the structure there are AlAs4-tetrahedra connected by common corners to „Einereinfach\" chains. The new compound Ba3AlSb3 crystallizes in the orthorhombic system (space group: Cmca) with a = 2113.3(10) pm, b = 719.4(5) pm, c = 1400.9(8) pm. AlSb4-tetrahedra are connected by common edges to isolated Al2Sb6 groups. According to the compositions and structures both compounds belong to the Zintl-phases.

Über eine Hochdruckmodifikation des SrAl2 / On a High Pressure Modification of SrAl2

Abstract: SrAl2, forming at standard conditions the KHg2 structure type, transforms at ~60 kbar and 1050 °C to a high pressure modification with the MgCu2 structure (a = 832.5(5) pm).

Trimethylsilylverbindungen der Vb-Elemente, HI [1]. Tris(trimethylsilyl)- und Tris(trimethylstannyl)bismutan sowie Tetrakis(trimethylsilyl)dibismutan / Trimethylsilyl Derivatives of Vb-Elements, III [1]. Tris(trimethylsilyl)- and Tris(trimethylstannyl)bismuthine as well as Tetrakis(trimethylsilyl)dibismuthine

Abstract: Abstract Chlorotrimethylsilane and sodium/potassium bismuthide, easily prepared from finely powdered bismuth and sodium potassium alloy in 1,2-dimethoxyethane (DME), react to give tris(trimethylsilyl)bismuthine (1) in 48% yield. When compound 1 is treated with chlorotrimethylstannane all trimethylsilyl substituents are successively replaced by stannyl groups, and tris(trimethylstannyl)bismuthine (4) is obtained. As in analogous reactions of other tris(trimethylsilyl) derivatives of Vb-elements with methyl lithium in diethylether/tetrahydrofuran (THF), one trimethylsilyl group of tris (trimethylsilyl)-bismuthine (1) can also be removed, and lithium bis(trimethylsilyl)bismuthide · 2 THF (5) is formed. With 1,2-dibromoethane bismuthide 6 reacts with metal halogen exchange to give green lustrous needles of tetrakis(trimethylsilyl)dibismuthine (6). In contrast to other dibismuthines described in the literature, this compound is thermally rather stable and can be isolated in preparative amounts. Similar to several distibines a colour change from green to red, resp. orange-red occurs on melting or dissolving dibismuthine 6 in organic solvents.

Metallkomplexe funktioneller Isoeyanide, VI [1] Tosylmethyl-, Benzyl- und Benzhydrylisocyanid-Metallverbindungen und ihre Reaktionen mit Nucleophilen und 1.3-Dipolarophilen/Metal Complexes of Functional Isocyanides, VI [1] Tosylmethyl-, Benzyl- and Benzhydrylisocyanide Metal Complexes and Their Reactions with Nucleophiles and 1,3-Dipolarophiles

Abstract: Abstract Metal complexes of the type M(CO)5L (M = Cr, W), MX2L2 (M = Pd, Pt; X = Cl, Br, I), PtCl2(L)PPh3, and [Pt(Cl)(L)(PPh3)2]BF4 have been prepared with L = CNCH2SO2C6H4-pCH3, CNCH2Ph, and CNCHPh2, and reacted with a variety of nucleophiles (NH2CH2CO2CH3, CH(CN)2-, CH(CN)CO2CH3-, OH-) and 1,3-dipolarophiles (CF3CN, CH3O2CC ≡CCO2CH3, CH2 = CHCN, RNCO (R = CH3, Ph), RCHO (R = i-C3H7, Ph, C6H4-oOH)) to give carbene, α-aminovinyl, and carboxamido complexes, and C2-metallated heterocycles (imidazoles, pyrroles, oxazolos, oxazolines), respectively. Ready dealkylation occurs of benzhydryl isoeyanide in [Pt(Cl)(CNCHPh2)(PPh3)2]BF4.

Neue Ga-Cluster-Verbände im Na7Ga13-II / New Ga-Cluster Compounds: The Structure of Na7Ga13-II

Abstract: Abstract Na7Ga13-II crystallizes in the orthorhombic system, space group Pnma with the constants a - 1562.5(3) pm, b = 1497.9(3) pm, c = 2167.8(4) pm. The Ga-atoms form Gaj.2 icosahedra and Gais clusters connected to a threedimensional network. The centres of these clusters correspond to the atomic positions of the MgCu2 structure. The number of bonding electrons is related to the Na content of the compound

A Comparative Study of Metal Shielding in Low Valent Vanadium, Niobium and Manganese Complexes

Abstract: Variations of the metal chemical shifts δ(⁵¹V), δ(⁵⁵Mn) and δ(⁹³Nb) with the paramagnetic deshielding contribution to the overall shielding are discussed in terms of influences imposed by the ligand field splitting, the nephelauxetic effect and the covalency of the metal-to-ligand bond. Complexes under investigation are isoelectronic and/or iso-structural series [M(CO)₆₋ₙLₙ]q (M = V, Nb: q = -1; M = Mn: q = + 1; n = 0-6), η⁵-C₅H₅M(CO)₄₋ₙLₙ (M = V, Nb; n = 0-4) and η⁵-C₅H₅M(L')₂L (M = V, L' = NO; M = Mn, L' = CO). L is a monodentate or l/n oligodentate phosphine. η varies with the point symmetry of the complex, and with ligand parameters of primarily electronic or steric origin. Generally, for weak to medium π-interaction, there is a decrease of shielding with decreasing π-acceptor power of the ligand, increasing ligand bulkiness, increasing ring strains in chelate structures and increasing degree of substitution. For strong π-interaction, the trends may be interconverted. PF₃ is shown to be a slightly weaker π-acceptor than CO. Selected results on nuclear-spin spin coupling constants, ¹³C and ³¹P shielding are also presented

Synthese und Reaktivität von Silicium-Übergangsmetallkomplexen, XIV [1] Umsetzung von Cp(CO)2Fe-substituierten Silieium-Wasserstoff-Verbindungen mit DicobaJtoctacarbonyl: Synthese von Siliciumverbindungen mit zwei, drei und vier Übergangsmetall -Liganden / Synthesis and Reactivity of Silicon Transition Metal Complexes, XIV [1] Reaction of Cp(CO)2Fe-Substituted Silanes with Dicobaltoctacarbonyl: Synthesis of Silicon Compounds with Two, Three and Four Transition Metal Ligands

Abstract: The reaction of Cp(CO)2Fe-SiHCl2 with Co2(CO)8 yields the heteronuclear complex Cp(CO)2Fe-SiCl2-Co(CO)4 (1) and HCo(CO)4.1 is degradated by AgBF4 to Cp(CO)2Fe-SiF3. PMe3 transforms 1 to Cp(CO)2Fe-SiCl2-Co(CO)3PMe3 (2). LnM-SiH2Me reacts with Co2(CO)8 to give LnM-SiMe-Co2(CO)7 [LnM = Cp(CO)2Fe (3a), Cp(CO)2PMe3W (3b)]. Starting with Cp(CO)2Fe-SiH3, μ3-Cp(CO)2Fe-SiCo3(CO)9 (4), the second example of a μ3-metallosilylidine tricobalt cluster is obtained in high yield, which is cleaved by acetic acid to Cp(C0)2Fe-Si[OC(O)Me]3 (5). The composition and structure of the silicon transition metal complexes 1-5 is proved by NMR, IR and mass spectroscopy. 29Si NMR shifts are determined for the first time for a tri- and tetra-metalated silicon species

Heteronucleare Clustersysteme, XX [1] μ3-Bi8mutio-cyclo-tris(tricarbonyliridium) (3 Ir-Ir), BiIr3(CO)9 Darstellung und Strukturuntersuehung eines neuartigen Iridiumclusters / Heteronuclear Cluster Systems, X X [1] μ3-Bismutio-cyclo-tris(tricarbonyliridium)(3Ir-Ir), BiIr3(CO)9 - Synthesis and Structural Investigation of a Novel Iridium Cluster

Abstract: Abstract The synthesis of BiIr3(CO)9 is described. IR and mass spectroscopic data are discussed. The structure of BiIr3(CO)9 was solved by X-ray analysis. The structural data are discussed and compared with those of the related compounds Ir4(CO)12 and Bi[Co(CO)4]3, respectively

Kristallstruktur der sulfidverbrückten Gold(I)verbindung [Au{S(AuPPh3)2}2]+ [(CH3)3SnCl2]— / Crystal Structure of the Sulphide-bridged Gold(I) Complex [Au{S(AuPPh3)2}2]+[(CH3)3SnCl2]–

Abstract: The compound [Au{S(AuPPh3)2}2]+[(CH3)3SnCl2]- was prepared by the reaction of Ph3PAuCl with ((CH3)3Sn)2S and characterised by an X-ray structure determination [C2/c, a = 1713.4(5), b = 2996.7(12), c = 3081.7(12) pm, β = 102.40(3)°, Z = 8, R = 0.074]. The cation displays short Au ··· Au contacts and narrow Au-S-Au angles ( < 90°). The chlorine atoms of the anion are axially arranged. There are two independent anions, one lying on, and the other disordered about, the crystallographic twofold axes

Verbascosid und Isoverbascosid aus Paulownia tomentosa Steud. / Verbascoside and Isoverbascoside from Paulownia Tomentosa Steud

Abstract: The structure of verbascoside and isoverbascoside, isolated from the leaves of Paulownia tomentosa Steud have been determined by NMR spectroscopy and partially hydrolysis to be β-(34-dihydroxyphenyl)ethyl-O-a-1-rhamnosyl(1→3)-β-D-(4-0-caffeoyl)-glucopyranoside (1) and β-(34-dihydroxypehenyl)ethyl-O-a-L-rhamnosyl(1→3)-β-D-(6-O-caffeoyl)- glucopyranoside (2)

Borkomplexe mit Dicarbonsäuren: Bis(oxalato)borate und Bis(malonato)borate/Boron Complexes with Dicarboxylic Acids: Bis(oxalato)borates and Bis(malonato)borates

Abstract: Abstract Several bis(oxalato)borates and bis(malonato)borates have been prepared in heterogeneous reaction from boric acid, dicarboxylic acid and dicarboxylic salt by refluxing in benzene under continuous separation of water. The compounds were characterized by their IR and 11B NMR spectra. The vibrational spectra of the bis(oxalato)borate are discussed in detail.

Organoaluminum Radical Complexes from the Single Electron Transfer Reaction of Diisobutylaluminum Hydride with N-Heterocycles

Abstract: Abstract Diisobutylaluminum hydride iBu2AlH reacts with N-heterocycles L (L = pyrazine, 2,2'-bipyridine, 4,4'-bipyridine) via single electron transfer to yield 1:1 radical complexes [L(AliBU2)·].