Telluronium salt chemistry: Some fluorides and carboxylates

Ph₃TeF is ionic and no evidence is obtained for a covalent form in solvents of relatively low polarity. By contrast significant covalent interaction is seen for Ph₂(CH₃)Te(OOCR)(R=Ph, o-CH₃O·C₆H₄-, m-NO₂·C₆H₄). Factors influencing the formation and stability of covalent forms of telluronium “salts” are discussed. Phenyl(methyl)telluronium-ortho-phthalate is shown to be a monomer in chloroform solution. The structure of the compound is discussed in relation to NMR and IR data and against the background of previous literature reports of both dimeric and monomeric diorganotellurium-ortho-phthalates.     

On the utilization of pulse ultrasonic nebulization for analyzing small volumes of solution by flame emission spectrometry

A pulse ultrasonic nebulizer system capable of reproducibly introducing small sample volumes into a flame for analysis by flame emission spectrometry i     

Reactions of collman complex with tin(IV) and germanium(IV) porphyris,formation of [tin(II) and germanium(II) porphyrins] tetracarbonyliron and crystal structure of [2,3,7,8,12,13,17,18-octaethylporphinato tin(II)] tetracarbonyliron

The action of Na₂Fe(CO)₄ with tin(IV) and germanium(IV) porphyrins affords metal(II) porphyrin complexes [(por)M(II)Fe(CO)₄] (por = porphyrinate, M - Sn(II) or Ge(II)). The molecular structure of [(oep)Sn(II)Fe(CO)₄] was solved by X-ray diffraction techniques. The molecular structure of [(oep)Sn(II)Fe(CO)₄] was solved by X-ray diffraction techniques : the Sn coordination is square pyramidal with the iron in axial position (Sn-Fe = 2.492(1)Å) whereas the Fe coordination is trigonal bipyramidal. Mössbauer parameters provide convincing evidence for the formal zero oxidation state of the iron atom.     

Photosubstitution reactions in potassium octacyanomolybdate(IV) and octacyanotungstate(IV) in the presence of 1,10-phenanthroline and 2,2-́bipyridyl

Substitution reactions take place following the photonic excitation of aqueous K₄M(CN)₈ (where M = Mo or W) in the presence of 1,10-phenanthroline and 2,2$\text{-}\text{?}$bipyridyl. Changes in absorbance with time show that the overall reaction is dependent on photochemical activation of potassium octacyanomolybdate(IV) and -tungstate(IV). The species [K₂Mo(CN)₄(OH)₂(phen)], [K₂W(CN)₄(OH)₂(phen)], [K₂Mo(CN)₄(OH)₂(bipy)] and [K₂W(CN)₄(OH)₂(bipy)] exist in solution. The final photosubstitution products [Mo(OH)₃(CN)(phen)₂] · 2H₂O], [Mo(OH)₃(CN)(bipy)₂] · 3H₂O, [W(OH)₃(CN)(phen)₂] · 2H₂O and [W(OH)₃(CN)(bipy)₂] · H₂O have been isolated in the solid state. Their IR spectra have been discussed. The quantum yield of the photosubstitution reactions has been determined and its variation with change of concentration of the complex as well as the H⁺ ion concentration has been studied.     

Subject index

We have investigated the Penning ionization of NO₂(²A₁) by He(2³S) by means of electron—ion coincidence measurements. It is possible to identify two entrance channels. The quartet state is essentially repulsive and gives rise to an electron energy spectrum similar to that found in photoionization. The doublet entrance channel is strongly attractive with a well depth D_e of 4.8 {_?0.3^+0.1 eV. Ionization out of this channel leads to very broad features in the electron energy spectrum.     

Tungsten(V) dimeric complexes with heterocyclic dithiocarbamates

In this paper we report the syntheses and study of a number of oxo- and sulphido-bridged tungsten(V) complexes with morpholine dithiocarbamate and piperidine dithiocarbamate as ligands. We assign the following formulae to the complexes: W₂O₃(Rdtc)₄, W₂O₄(Rdtc)₂, W₂O₂S₂(Rdtc)₂ and W₂O₃S(Rdtc)₂ (where R = morpholine and piperidine), based on the analytical data. We have studied the complexes by IR and electronic spectra, and magnetic susceptibility measurements. We assign in the IR spectra the following bands: W=O (ν_s=939–948 cm^?1), W-O_b(ν_a=813–819 cm^?1, ν_s = 431–448 cm^?1), W-S_b (ν_a=470–476 cm^?1, ν_s = 368–370 cm^?1, C-N (β = 1511–1519 cm^?1) and C-S (ν = 1090–1113 cm^?1). The low values of the magnetic moments (0.03–0.60 B.M.) are in accordance with a dimeric species of tungsten(V).     

Velocity dependence of vibrational branching ratios in electronic energy transfer collisions of metastable argon atoms with nitrogen

Measurements have been made of the vibrational branching ratio (υ′=0)/(υ′=1) in N^*₂ (C³Π_u) formed in electronic energy transfer collisions between argon metastable atoms and ground state nitrogen molecules, using crossed molecular beams. In the relative collision energy range, 0.08–0.20 eV, this ratio is 3.5±0.2.     

Dependence of the spectral width of the self-absorbed Sr 4607.33Åresonance line on Sr atomic density in a flame

Using a pressure-scanned Fabry-Pérot interferometer, we measured spectral profiles of the self-absorbed Sr resonance line at 4607.33Åemitted in a pre-mixed, laminar, shielded air-C₂H₂ flame at 1 atm for various Sr-solution concentrations. The dependence of the full width at one-half maximum (FWHM) on Sr atomic density in the flame was found to agree with a calculation based on the Voigt expression and Beer's law. It appears that one can derive the FWHM under optically thin conditions (i.e. at vanishing Sr atomic density) by linear extrapolation from measurements made at higher concentrations where the signal-to-noise ratio is good, but broadening due to self-absorption plays a role.     

Infrared spectra of ν-cyclopentadienylberyllium chloride and bromide and of dicyclopentadienylberyllium: a comparative study

The IR spectra of η⁵-cyclopentadienylberyllium chloride and bromide and of dicyclopentadienylberyllium in solution are compared. Evidence is given for pentahapto- and monohapto-attachment of the cyclopentadienyl rings for the structure of dicyclopentadienylberyllium in solution.