Dibenzotetraazamacroheterocycles: Synthesis and properties. (Review)

Data on the synthesis, complexing ability, practical applications, and biological activity of dibenzotetraazamacroheterocycles of the azacrown ether, amide, and azomethinedibenzotetraazacycloalkane types and also dibenzotetraazamacroheterocycles containing amide and azomethine fragments are classified and analyzed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1763–1796, December, 2005.     

(Halomethyl)arsenic compounds : I. Synthesis and characterization of (chloromethyl)arsine

(Chloromethyl)arsine, ClCH₂Ash₂, can be prepared by the reduction of chloromethylarsonic acid. Bromomethyl and iodomethyl analogs could not be prepared. NMR, IR, and mass spectra data are included.     

Thiacrown compounds: Synthesis and properties. (Review)

Data of the last 15 years on the synthesis and properties of various thiacrown compounds containing 2–8 sulfur atoms in the ring are reviewed.M. V. Lomonosov Moscow State University, Moscow, RussiaTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1587–1618, December, 1999.     

(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.     

(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 -     

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.     

Solvatochromism of Heteroaromatic Compounds: XIII. Methyl(aroyloxymethyl)fluorosilanes and (Aroyloxymethyl)trifluorosilanes

The UV spectra of heptane solutions of methyl(aroyloxymethyl)fluorosilanes and (aroyloxymethyl)trifluorosilanes of the general formula 4-RC₆H₄COOCH₂Si(Me)_{3 - 4n} F _n (n = 1-3; R = H, F, Cl, Me, MeO, O2N) were studied. The intramolecular coordination bond Oarr;Si causes a bathochromic shift of the second -* transition, because the energy gap between the ground electronic and Franck-Condon excited states decreases owing to additional stabilization of the latter. The spectral shifts correspond to stabilization of the five-coordinate state of the silicon atom in (aroyloxymethyl)trifluorosilanes by 5-6 kcal mol^{- 1}.     

Organosilane polymers. II. Poly(ethylmethyl-co-dimethylsilylene) and poly(methylpropyl-co-dimethylsilylene)

Polydimethylsilylene is a largely crystalline, high-melting polymer that is soluble only above 200°C and does not thermoform below its decomposition temperature. Introduction of ethyl and propyl substituents into the linear silylene system by random copolymerization of dimethylsilylene with ethylmethyl- and methylpropylsilylenes leads to tractable polymers that are soluble in common solvents at normal ambient temperatures.