(Organylthio)chloroacetylenes: VII. Hydrochlorination of (Alkylthio)chloroacetylenes

(Alkylthio)chloroacetylenes are readily hydrochlorinated with hydrogen chloride in dioxane to form a mixture of (E)- and (Z)-1-(alkylthio)-1,2-dichloroethenes, as well as 1-(alkylthio)-1,1,2-trichloroethanes.     

Technetium(I) tricarbonyl complexes: potential precursors of the radiopharmaceuticals. Part II: phenethylbiguanide (phenformin)

The radiosynthesis of [^99mTc]-phenformin ([^99mTc]-1-phenethylbiguanide) complex and its suitability as precursor of the radiopharmaceuticals for the tumor imaging was assessed. Radiochemical purity of the [^99mTc]-complex was determined using radio-TLC and was studied by the HPLC with radiochemical detection, while its stability in challenge experiments. The results show, that due to the sufficient stability and lipophilicity of the complex, it fulfills our expectations for promising radiopharmaceutical precursor not only for the diagnostic agent, but also for the drug suitable for the oncological Auger electron therapy.     

(Organylsulfanyl)chloroacetylenes: VIII. Reaction with (diethylamino)trimethylsilane

(Alkylsulfanyl)chloroacetylenes react with (diethylamino)trimethylsilane in diethyl ether (20–22°C) to form dialkyl(alkylsulfanylethynyl)amines (19–29%) and 1,3-bis(alkylsulfanyl)-4-chloro-4-(diethylamino)but-3-en-1-ynes (17–42%). The yield depends on the reagent ratio.     

W. Ekardt (ed): Metal clusters. (Wiley Series in Theoretical Chemistry)

Journal of Solid State Electrochemistry -     

On the electronic structure of giant polyoxometalates: Mo(132)vs. W(72)Mo(60)

The molecular and electronic structure of the spherical Keplerates [{(Mo(VI))Mo(VI)(5)O(21)}(12)(Mo(V)(2)O(4))(30)](12-) (Mo(132)) and [{(W(VI))W(VI)(5)O(21)}(12)(Mo(V)(2)O(4))(30)](12-) (W(72)Mo(60)) has been determined, for the first time, using first-principles density functional theory (DFT) based methods including solvent effects. Computed geometric parameters are in very good agreement with X-ray data, whereas the electronic structure reveals the archetypal nature of polyoxometalates.     

Organothallium compounds : XVII. Halogenobis(polyfluorophenyl)thallium(III) complexes

The preparations, stabilities and structures of the complexes R₂TlX and R₂ LTlX (R = C₆F₅, p-HC₆F₄, or o-HC₆F₄; X = Br or Cl; L = Ph₃PO, 2,2′-bipyridyl (bpy) or Ph₃P) have been examined or (R = C₆ F₅) reinvestigated. The derivatives R₂TlX are monomeric in acetone, from which the complex (p-HC₆F₄)₂ Me₂COTIBr has been isolated. In this solvent, the complexes R₂LTlX (L = Ph₃PO, bpy, or Ph₃P) undergo partial dissociation by loss of L. When L = bpy, there is also slight ionization into R₂LTl⁺ and R₂TlX^?₂. The acceptor properties of R₂TlX compounds towards uncharged ligands decrease R = C₆F₅ ? p-HC₆F₄ > o-HC₆F₄ > Ph. Dimeric behaviour is observed for R₂TIX compounds in benzene, whilst R₂LTlX (L = Ph₃PO or bpy) derivatives show slight but significant association. In the solid state, R₂TlX compounds are considered to be polymeric with five coordinate thallium, and R₂LTlX derivatives to be dimeric with five (L = Ph₃PO) or six (L = bpy) coordinate thallium by contrast with four coordinate dimeric and four or five coordinate monomeric structures previously proposed for the respective pentafluorophenyl derivatives. Halogen bridging is unsymmetrical for R = C₆F₅ or p-HC₆F₄, but may be more symmetrical for R = o-HC₆F₄ when L = Ph₃PO or bpy. Reported structural data for the complexes (C₆F₅)LTlX (L = Ph₃AsO, Ph₃P, Ph₃As, or 1,10-phenanthroline; X = Br or Cl) and (C₆F₅)₂TlCl^?₂ are reinterpreted and the proposed structures revised.     

1,8-dihydroxyanthraquinone-Mg(II) complex: II. Spectrophotometric study. Determination of Mg(II)

The 1,8-dihydroxyanthraquinone (1,8-DHAn) shows a colored and fluorescent reaction with the ion Mg(II) in a hydroalcoholic and ammonical medium.In the present work we have studied spectrophotometrically the 1,8-DHAn-Mg(II) complex in a hydroethanolic and ammonical, 8 × 10^?4M medium. We found that the complex shows a maximum absorbance at 510 nm, and obeys a 1:1 stoichiometry with log K of 4.08.We propose a new method for the spectrophotometric determination of Mg(II) which is valid for concentrations between 0.25 and 2.00 ppm, and yields an error of 1.32%.