Mass spectrometric study of apogalanthamine and its derivatives

Conclusions 1. The mass spectra of apogalanthamine, its monomethyl ether, and the acetate of the monomethyl ether have been studied.2. The general nature of the fragmentation of these compounds and of alkaloids of the galanthamine type has been shown and specific features of fragmentation due to the presence of the second aromatic ring have been determined.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 6, pp. 519–521, 1969     

Mass spectrometric study of 2- and 4-silalactones

In contrast to the previously investigated 1-silalactones, ejection of a CO₂ molecule from the molecular ion is not characteristic in the disintegration of 2- and 4-silalactones under electron impact. Migration of the silicon atom to the oxygen atom during fragmentation of the 2- and 4-silalactones was observed. The dependence of the paths of disintegration of the silalactones on the ring size and the number of methylene links was established. The possibility of the identification of isomeric 2-silalactones on the basis of their mass spectra was observed.     

Synthesis and structures of silicon-, germanium-, and tin-containing imido-alkyl molybdenum complexes (ArN)2Mo(CH2EMe3)2 (E = Si, Ge, Sn)

New silicon-, germanium-, and tin-containing imido-alkyl molybdenum complexes (ArN)₂Mo(CH₂EMe₃)₂ (Ar is 2,6-diisopropylphenyl; E = Si (1), Ge (2), Sn (3)) were prepared in the crystalline state in 58–66% yields by the reactions of the (ArN)₂MoCl₂(DME) complex with alkyllithium derivatives Me₃ECH₂Li (E = Si or Ge) or the Grignard reagents Me₃ECH₂MgCl (E = Ge or Sn). The structures of complexes 1–3 and the known analog (ArN)₂Mo(CH₂Bu^t)₂ (4) were established by X-ray diffraction analysis. Complexes 1–3 were found to be isostructural. The coordination environment about the Mo atom can be described as a distorted tetrahedron. Complex 4 has a similar structure. The Mo-C distance tends to decrease with increasing electron donating ability of the EMe₃ group.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 597–600, March, 2005.     

Modification of anode surface in organic light-emitting diodes by chalcogenes

Influence of thin chalcogen X (S, Se, Te) interlayer between anode (indium-tin oxide, ITO) and a layer of N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD) used as a hole-transport layer (HTL) on the operating characteristics of organic light-emitting diodes (OLEDs) of composition ITO/X/TPD/Alq₃/Yb (Alq₃ - aluminum 8-quinolinolate) has been investigated. It was found that the sulphur layer decreases operating voltage and enhances operating stability of a device while the selenium or tellurium interlayers impair these characteristics.     

Synthesis, properties, and the crystal structure of the complex Cp2Yb(DAD)

The diazadiene complex of trivalent ytterbium, Cp₂Yb(DAD) (1) (DAD=Bu^t−N=CH−CH=N−Bu^t) was prepared according to three different procedures, namely, by oxidation of Cp₂Yb(THF)₂ with diazadiene in THF, by the reaction of Cp₂YbCl with DAD²⁻Na⁺ ₂ taken in a ratio of 2∶1, and by the reaction of Cp₂YbCl(THF) with DAD²⁻Na⁺ ₂ taken in a ratio of 1∶1. Complex1 was characterized by microanalysis, IR spectroscopy, magnetochemistry, and X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 384–386, February, 1999.     

Polynuclear germanylmercury complexes of lanthanides

Conclusions The transmetallation of [(C₆F₅)₃Ge]₂Hg with metallic praseodymium, neodymium, and holmium yielded complexes [(C₆F₅)₃Ge]₇Hg₂Ln·3DME (DME is dimethoxyethane), for which the ionic structure {[(C₆F₅)₃Ge]₇Hg₂}^3–Ln³⁺·3DME was proposed on the basis of electrical conductivity and chemical properties.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2589–2594, November, 1981.The authors thank O. N. Babkina at the Institute of Chemical Physics of the Academy of Sciences of the USSR for electrical conductivity measurements.     

Metallocenes in oxidative-reductive transmetallzation with bis[tris(pentafluorophenyl)germyl]mercury

Conclusions The oxidative-reduction transmetallation reaction between bis[tris(pentafluorophenyl)-germyl]mercury and the dicyclopentadienyl derivatives of various metals can yield ionic multinuclear ate-type complexes, covalent compounds with a metal-metal bond, or ionic complexes that form by transfer of a cyclopentadienyl anion from the central metallocene atom to mercury.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2548–2555, November, 1986.The authors thank N. Walker and D. Stuart for providing the DIFABS program.     

A mass spectrometric investigation of alkaloids of the galanthamine type

Conclusions 1. Features of the mass spectrometric behavior of alkaloids of the galanthamine type have been established: the presence of strong M⁺ and M — 1 peaks, the contraction of ring C with the retention or with the expulsion of the nitrogen atom, and the elimination of the elements of ring B.2. Additional information on the structure of the alkaloid chlidanthine has been obtained.3. The similarity of the mass spectrometric behavior of a dihydro derivative of galanthamine (lycoramine) and of dihydro derivatives of alkaloids of the lycorine type have been shown.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 5, pp. 280–283, 1969     

A Novel Route to Triphenylgermyl Europium Complexes. Crystal Structure of (Ph3Ge)2Eu(DME)3

(Ph₃Ge)₂Eu(THF)₄ ( 1 a ) and (Ph₃Ge)₂Eu(DME)₃ ( 1 b ) have been synthesized by reacting Ph₃GeH with europium naphthalene, C₁₀H₈Eu(THF)₂, in THF or DME, respectively. The reaction of Ph₃GeH with C₁₀H₈[EuI(DME)₂]₂ in DME yielded Ph₃GeEuI(DME)₂ ( 2 ). The addition of two equivalents of CH₃I to a solution of 1 b in THF produced Ph₃GeMe and EuI₂(DME)₂ with almost quantitative yields. Complex 2 easily disproportionates forming mixtures of 1 b and EuI₂(DME)₂. The molecular structure of 1 b was determined from X-ray diffraction data.