Metallierungsreaktionen an cyclometallierten komplexen des typs Mo-C6H4CH2PR2)2(M = Pd,Pt)

The complexes of type $\text{M}\text{o}\text{-C}{}_6\text{H}{}_4\text{CH}{}_2\text{P}$R₂)₂ (M = Pd, Pt) are readily deprotonated by n-Buli under various conditions yielding μ-C-bis-dilithiated species. The resulting carbanions are attacked by the electrophiles Mel, Me₃SiCl and Ph₂PCl to form the corresponding disubstituted derivatives. The reaction with AuCl . PPh₃ yields heterobimetallic complexes with two different MC σ-bonds. The compounds obtained are analytically and spectroscopically characterized.     

Superexcited state reconstruction of HCl using photoelectron and photoion imaging

The velocity-map imaging technique was used to record photoelectron and photofragment ion images of HCl following two-photon excitation of the E Sigma(+)(0+), V 1Sigma(+)(0+) (nu=9,10,11) states and subsequent ionization. The images allowed us to determine the branching ratios between autoionization and dissociation channels for the different intermediate states. These branching ratios can be explained on the basis of intermediate state electron configurations, since the configuration largely prohibits direct ionization in a one-electron process, and competition between autoionization and dissociation into H* (n=2)+Cl and H+Cl*(4s,4p,3d) is observed. From a fit to the vibrationally resolved photoelectron spectrum of HCl+ it is apparent that a single superexcited state acts as a gateway to autoionization and dissociation into H+Cl*(4s). Potential reconstruction of the superexcited state to autoionization was undertaken and from a comparison of different autoionization models it appears most likely that the gateway state is a purely repulsive and low-n Rydberg state with a (4Pi) ion core.     

Unusual peak defocusing in capillary GC on hexakis(2,6-diO-pentyl-3-O-acetyl)-α-cyclodextrin stationary phase

An unusual peak defocusing effect influencing chromatographic performance over a limited range of elution temperatures is described for hexakis(2,6-di-O-pentyl-3-O-acetyl)-α-cyclodextrin stationary phase. Since this phenomenon is likely to be dependent on minor details of the cyclodextrin molecule, full assignment of the ¹H- and ¹³C-NMR-spectra are given.     

Identification of oxygenated polycyclic aromatic hydrocarbons in diesel particulate matter by capillary gas chromatography and capillary gas chromatography/mass spectrometry

Summary Using a two-step liquid chromatographic separation on normalphase cartridges, crude extracts of diesel particulate matter can be separated without time-consuming sample handling into special fractions which mainly contain slightly-polar oxygenated polycyclic aromatic hydrocarbons (oxy-PAH) and nitrated polycyclic aromatic hydrocarbons (nitro-PAH). Subsequent analysis was by fused-silica capillary gas chromatography on a SE54 column along with flame-ionisation (GC/FID) and positive-ion electron-impact mass spectrometric detection (GC/MS) respectively. A number of individual oxy-PAH belonging to four different chemical classes (ketones, quinones, anhydrides and aldehydes) and several individual nitro-PAH were characterized by their retention times and mass spectra. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984     

Schwefeldioxid als Ligand und Synthon. XIII. Reaktionen von Isocyanid-tris(triphenylphosphan)nickel(0)-Komplexen mit Schwefeldioxid und N-p-Tolylsulfinylamin

Sulfur Dioxide as Ligand and Synthon. XIII. Reactions of Isocyanide-tris(triphenylphosphane)nickel(0) Complexes with Sulfur Dioxide and N-p-tolylsulfinylamine Reactions of the isocyanide-tris(triphenylphosphane)-nickel(0) complexes [(RNC)Ni(PPh₃)₃] (R = ^tBu, Cy, PhCH₂, p-TosCH₂) with SO₂ and p-TolNSO are described. The sulfur dioxide and N-p-tolylsulfinylamine complexes obtained by PPh₃ ligand substitution have been characterized by means of i.r. and ³¹P n.m.r. spectra. The X-ray crystal structure of [(Ph₃P)₂(CyNC)Ni(SO₂)] · 0.5 PhMe and (Ph₃P)(^tBuNC)Ni(η²-p-TolNSO) have been determined.     

Zur Struktur und Reaktivität von stannylierten Propylaminen und -sulfiden. Kristall- und Molekülstruktur von Bis(3-dimethylchlorostannylpropyl)sulfid S(CH2CH2CH2SnMe2Cl)2

Structure and Reactivity of Stannylated Propyl Amines and Propyl Sulfides. Crystal and Molecular Structure of Bis(3-chlorodimethylstannylpropyl)sulfide S(CH₂CH₂CH₂SnMe₂Cl)₂ The synthesis and reactivity of stannylated propyl amines and propyl sulfides, respectively, E(CH₂CH₂CH₂SnMe₃)₂ ( 1 , E ? NMe; 2 E ? S) and N(CH₂CH₂CH₂SnMe₃)₃ 3 are reported. 1 and 3 react with dimethyl dichlorostannane under thermal cyclisation to 1,5-dimethyl-5-chloro-1aza-5-stannabicyclo[3.3.0^1,5]octane Me(Cl)Sn(CH₂CH₂CH₂)₂NMe 4 and 5-chloro-1-aza-5-stannatricyclo[3.3.3.0^1,5]-undecane ClSn(CH₂CH₂CH₂)₃N 5 , respectively. The reaction of 2 with dimethyl dichlorostannane leads to the formation of bis(3-chloro-dimethylstannylpropyl)sulfide S(CH₂CH₂CH₂SnMe₂Cl)₂ 6 , whereas the treatment of 2 with tin tetrachloride yields the bis(3-di-chloro-methylstannylpropyl)sulfide S(CH₂CH₂CH₂SnMeCl₂)₂ 7 . The ¹H, ¹³C, and ¹¹⁹Sn NMR data are discussed. 6 crystallizes in the ortho-rhombic space group Pna2₁ with the unit cell parameters a = 2275.0(1), b = 733.6(2), c = 1062.0(4) pm, V = 1.77273 nm³, Z = 4. The structure was refined to a final R value of 0.041. Both tin atoms adopt distorted trigonal bipyramidal configurations as a result of intramolecular interactions with the bridging sulphur. The sulphur and the chlorine atoms occupy the apical positions. The Sn? S distances amount to 309.7(4) and 311.8(4) pm.     

Absolute Configuration of 3-Substituted 1-Azabicyclo[2.2.1]heptanes

The l-azabicyclo[2.2.1]heptan-3-exo-ol ( 2 ) was resolved by fractional crystallisation of its hydrogen tartrate salts. The enantiomers (+)- and (?)- 2 were oxidised to the ketones (?)- 4 and (+)- 4 , respectively (Scheme). CD spectroscopy suggested that (?)- 4 possesses the (1R,4S)-configuration. This absolute configuration was confirmed by single-crystal X-ray diffraction of the derivative (+)-(1R,4R)-3-(1,3-dithian-2-ylidene)-1-azabicyclo [2.2.1]-heptane ((+)- 5 ).     

On the analysis of CO2, H2- and CO,H2-mixtures by water-gas potentiometry with solid electrolyte cells

The potentiometric analysis of CO₂, H₂ and CO, H₂O-mixtures using oxide ion-conducting solid electrolytes requires the adjustment of the water-gas equilibrium without side reactions in the high-temperature galvanic cell. Conventional cell designs suitable for the analysis of H₂, H₂O and CO, CO₂-mixtures are not applicable due to the insufficient gas residence times in the cells and the insufficient catalytical activity of the platinum electrodes. Solid electrolyte cells have to be modified by integrating of suitable catalysts. Under optimized conditions of gas velocity and cell temperature both gas systems can be analyzed only by measuring the cell tension U (=–emf) and temperature in the favorized temperature range around 813°C. Here systematical errors of the component ratio or the mole fraction were smaller than 6%. Several fundamental requirements for the application of catalysts in solid electrolyte cells for the analysis of reactive water-gas mixtures are pointed out.