Molecular emission cavity analysis : Part 29. Determination of Tin after Conversion to its Volatile Hydride

Tin(II) and tin(IV) (each 0–40μg ml^?1) are determined after reduction with sodium tetrahydroborate to volatile tin hydride, and collection in a cold trap. The SnO emission stimulated in an oxy-cavity placed in a hydrogen/nitrogen flame is measured at 408 nm. The detection limit is 80 ng ml^?1 tin (II) in a 1-ml sample. The depressive effects of some cations are eliminated by EDTA.     

Indirect extraction—spectrophotometric method for the determination of traces of tin(II) by means of 4,7-diphenyl-1,10-phenanthroline

An indirect extraction-spectrophotometric determination of tin(II) is based on reduction of iron(III) and determination of the iron(II) formed with bathophenanthroline. Analysis is possible in strongly acidic samples even with large excesses of iron(III). The apparent molar absorptivity is 39,080 dm³ mol^-1 cm^-1 ; the limit of determination is 32 ng cm^-3 and the sensitivity is 64 ng cm^-3. Interferences are reported. The method is applicable to the determination of tin in samples soluble in non-oxidizing acids, and to the determination of tin in lead.     

5-Thia-2,8(N-alkyl)diaza-1-stanna(II)-bicyclo[3.3.01,5]octane – Intramolekular basenstabilisierte Diazastannylene

5-Thia-2,8(N-alkyl)diaza-1-stanna(II)-bicyclo[3.3.0^1,5]octanes – Intramolecular Basestabilized Diazastannylenes The title compounds are obtained by transamination of tin(II) dimethylamide with compounds of the type S(CH₂CH₂N(R)H)₂ (R = t-Bu, i-Pr) or by reaction of tin(II) chloride with the corresponding lithium amides. The monomeric structure is proved by temperature dependend ¹H-, ¹³C-, ¹¹⁹Sn n.m.r., and Mössbauer measurements.     

Polarography of tin(II) chloride in acetonitrile

Polarographic and spectrophotometric data show that tin(II) chloride is a weak electrolyte in dilute acetonitrile solutions. The dominant species, SnCl₂, exists in a labile equilibrium with the ions SnCl⁺ and SnCl₃^- Oxidation and reduction of these ionic species is responsible for all observed polarographic plateaux. The dichloro—tin(II) molecule is shown to be a good acceptor species in acetonitrile solution, readily forming 1:1 complexes with ligands such as 4-picoline N-oxide.     

Zur Reaktivität von intramolekular basenstabilisierten Zinn(II)- Verbindungen mit Mercaptanen,Disulfiden und Peroxiden

Reactivity of Intramolecular Basestabilized Tin(II) Compounds with Mercaptanes, Disulfides, and Peroxides New pentacoordinated stannaocanes can be obtained in good yields by the reaction of intramoleculare basestabilized tin(II) compounds of the typ E(CH₂CH₂S)₂Sn (E = NMe, S) with mercaptanes RSH (R = Ph, PhCH₂) and disulfides RSSR (R = Ph, PhCH₂). The redistributation of the main product proceeds as a byreaction. The resulting spirocompounds and tin tetrathiolates have been determined by ¹¹⁹Sn-n.m.r. spectroscopy. The reaction of the tin(II) compound with dibenzoylperoxide only results in the addition product. All new compounds are characterized by ¹H-, ¹³C- and ¹¹⁹Sn-n.m.r. measurements and partially by i.r. investigations.     

Zinn(II)-halogenid-Komplexe mit Tri-tert-butylphosphin und Tris(dimethylamino)phosphin

Tin(II) Halide Complexes with Tri-tert-butylphosphine and Tris(dimethylamino)-phosphine TIn(II) chloride and tin(II) bromide react with tri-tert-butylphosphine and with tris(dimethylamino)phosphine to give stable 1:1 adducts. Infrared and raman data as well as¹H-n.m.r., ³¹P-n.m.r., and ^119mSn-Mössbauer spectra of the novel phosphine dihalogennostannylenes are discussed in terms of an ylidic type of bonding.     

Extraction and spectrophotometric determination of trace amounts of tin(II) with diphenylglyoxal bis(2-hydroxybenzoylhydrazone)

Diphenylglyoxal bis(2-hydroxybenzoylhydrazone) has been used as a sensitive reagent for the spectrophotometric determination of tin. This reagent forms an orange-yellow complex with stannous ion at pH 3.5–7.0 (λ_max = 455 nm, ? = 2.25 × 10⁴ liter mol^?1/cm^?1 while no reaction is observed with quadrivalent tin. The colored complex extracted into isobutyl methyl ketone has been used for the spectrophotometric determination of trace amounts of tin(II). The molar absorption in the organic solvent is 3.54 × 10⁴ liter mol^?1 cm^?1 and the compound shows its maximum absorbance at 455 nm. The interferences of foreign ions have been determined.     

6-(N-Methyl)aza-2,10-dithia-1-stanna(II)-bicyclo[4,4,01,6]decan – ein Zehnring mit transannularer Zinn-Stickstoff-Wechselwirkung

6-(N-methyl)aza-2,10-dithia-1-stanna(II)-bicyclo[4.4.0^1,6]decane – a Ten-membered Ring with a Transannulare Tin-Nitrogen Interaction The reaction of tin(II) butoxide with N-methyl-bis(γ-mercaptopropyl)amine in toluene leads to the title compound in good yield. Its structure is investigated by ¹H-, ¹³C-, and ¹¹⁹Sn-n.m.r. spectroscopy and mass spectrometry.     

Dialkyl (Alkylene) Dithiophosphate Adducts of Anhydrous Stannous Chloride: Synthesis,Characterization, and Biological Activities

Abstract

Dialkyl (alkylene) dithiophosphate adducts of stannous chloride were synthesized by the reaction of anhydrous tin(II) chloride (SnCl₂) and dialkyl (alkylene) dithiophosphoric acid in a 1:1 molar ratio, under anhydrous reaction conditions, below 5 °C in a closed vessel. The newly synthesized adducts were characterized by physicochemical and spectroscopic techniques [FT-IR, NMR (¹H, ³¹P, and ¹¹⁹Sn), and mass spectrometry]. Coordination modalities have indicated a donor–acceptor interaction between sulfur and tin(II) moieties, where tin(II) acts as a Lewis acid. The adducts were found to have significant antibacterial activity against Escherichia coli and Pseudomonas aeruginosa, and antifungal activity against Aspergillus niger and Candida albicans.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Cyclic and stripping voltammetry of tin at mercury hanging drop and film electrodes in acidic o-diphenol media in the presence of lead and cadmium

The influence of catechol, gallic acid and tiron on the voltammetric behaviour of tin(IV) in the presence of lead(II) and cadmium(II) was investigated at hanging drop and mercury film electrodes in perchloric acid, oxalic acid and formate supporting electrolytes. Under cyclic conditions, well separated peaks of tin, lead and cadmium are obtained in oxalic acid and formate solutions containing gallic acid or catechol; tiron suppresses the tin peaks significantly. The efficiency of the deposition of tin in the presence of catechol or gallic acid is less than that of lead, particularly at long deposition time. The best separation of the stripping peaks of tin, lead and cadmium is obtained in oxalic acid solution containing gallic acid or catechol. In perchloric acid solution containing gallic acid or catechol the second peak corresponding to tin oxidation is useful for determinations of tin in the presence of lead. Tin(IV) at the 10^-8 mol l^-1 level can be detemined in various salt solutions and in water samples in the presence of five-fold amounts of lead and cadmium.     

119mSn-Mössbauer-spektren von funktionell substituierten stannylenen und ihren stannio-komplexen mit chrom,molybdän- und wolfram-carbonyl-acceptoren

^119mSn Mössbauer data for a series of base-stabilized, intermolecularly associated tin(II) compounds ith O, Cl, P and As atoms bonded to tin are compared with isomer shifts (IS) and quadrupole splittings (QS) of their stannio complex derivatives with Cr, Mo and W carbonyls. Coordination at the tin lone-pair atom decreases IS to ca. 2.1 ± 0.2 mm s^?1 and increases the QS. QS values reflect the highly associated nature of the complexes (CO)₅MSn(Cl)E(t-Bu)₂ (M Cr, W; E  P, As) which are bridged through μ-E(t-Bu)₂ groups.     

Synthesis,characterization, and insecticidal activity of new tin (IV) complexes

A three-component reaction of dimethyltin dibromide with imidazo[1,2-a]pyridine, pyridine derivatives, or isoquinoline and allyl bromide in refluxing ethanol affords the ionic complex, bis(1-allylcycloiminium) dimethyltetrabromostannate (II). The reaction involves N-allylation of cycloimine accompanied by the coordination of two bromide ions with the tin atom of dimethyltin dibromide. The complexes have been characterized by infrared and ¹H NMR, ¹³C NMR, and ¹¹⁹Sn NMR studies. The X-ray crystal structure analysis of a complex reveals the tin atom to be hexacoordinated and the dimethyltetrabromostannate (II) anion having octahedral geometry. Some of the complexes tested for their insecticidal activity are found to exhibit strong activity against Tribolium castaneum insect with LC₅₀ ranging from 0.4 to 0.8 ppm.     

Synthesis,Spectral, and 3D Molecular Modeling of Tin(II) and Organotin(IV) Complexes of Biologically Active Schiff Bases Having Nitrogen and Sulfur Donor Ligands

Reaction of tin(II) chloride and dimethyltin dichloride with Schiff bases derived from S-benzyldithiocarbazate leads to the formation of a new series of tin(II) and organotin(IV) complexes of general formula SnCl ₂ .L and Me ₂ SnCl ₂ .L (where L = Schiff bases are derived from the condensation of S-benzyldithiocarbazate with heterocyclic aldehydes). An attempt has been made to prove the structures of the resulting complexes on the basis of elemental analysis, conductance measurements, molecular weight determinations, infrared, and multinuclear magnetic resonance ( ¹ H, ¹³ C, and ¹¹⁹ Sn NMR) spectral studies. A few representative ligands and their tin complexes have also been screened for their antibacterial and antifungal activities and found to be quite active in this respect.     

Potentiometric titration of trace amounts of mercury after a preliminary separation by a reduction method

Isolation and concentration of mercury by reduction of mercury(II) with acidic tin(II) chloride solution and absorption of mercury vapour in acidic permanganate solution is combined with potentiometric titration with dithiooxamide. The simple procedure is applicable to 5–100 ppb mercury in 1-dm³ samples. Recoveries from organomercurials are discussed.     

Oxidaiton of tin/II/ in air-kept hydrochloric acid solutions

An air-storage stability of tin/II/ chloride solution was studied by voltammetric and spectrophotometric methods. The chosen concentration range was due to the problems of the kits preparation for a^99mTc generator. The rate of oxidation of tin/II/ in the range of 0.04–12.5 mg.ml^–1 was shown to decrease with an increase in tin concentration. According to the obtained results one can determine maximal storage time for the correct practical use.     

A simple route to the 7H-cyclopenta[a]pentalene system: preparation of the 1,2,3,4,5,6-hexachloro-derivative.

Reaction of octachlorofulvene (3) with diazomethane leads to the formation of the tricyclic tetraene (4), which on dechlorination with tin(II) chloride gives 1,2,3,4,5,6-hexachloro-7$\text{H}$-cyclopenta[a]pentalene¹ (2).     

The oxidized complex of nickel with 4-carboxy-1,2-cyclohexanedionedioxime in alkaline media

The reaction of oxygen with a nickel(II) complex of 4-carboxy-1,2-cyclohexanedionedioxime in alkaline media was studied spectrophotometrically, polarographically, and by spectrophotometric titrations with tin(II) chloride. Magnetic susceptibility measurements were also performed. The rate of formation of the oxidized complex was found to be first order at 25° and 50°. The average values obtained for the rate constant k'₁ are (2.71 ± 0.23) x 10^-2 h^-1 (25°), spectrophotometrically; (5.99 ± 0.83) x 10^-2 h^-1 (50°), polarographically; (4.98 ± 0.90) x 10^-2 h^-1 (50°), titrimetrically; (2.87 ± 0.29) x 10^-2 h^-1 (50°), curve fitting. The value obtained for the rate constant K'₂ is (1.59 ± 0.16) x 10^-2 h^-1 (50°), curve fitting, The effect of reducing agents on the formation of the oxidized complex was studied. It was found that tin(II) chloride, hydrazine sulfate, and hydroxylammonium chloride prevented the formation of the oxidized complex. A reaction mechanism for the formation and decomposition of the oxidized complex is proposed.     

Determination of mercury traces by differential-pulse stripping voltammetry after sorption of mercury vapour on a gold-plated electrode

Trace mercury is reduced with tin(II) to mercury metal, which is volatilised by bubbling air through the solution. A certain fraction of this mercury is sorbed on a rotating gold disk electrode and stripped in a thiocyanate solution. The detection limit is about 30 ng Hg(II) in solution; the relative standard deviation is 6% for 100 ng Hg(II) (n = 7). The detection limit for mercury in air is 1.7 ng l^?1 with a preconcentration time of 10 min.     

The structure of nitratotriphenylstannyltin(II): A compound with a tin(IV)tin(II) bond

A compound of formula [Sn^II(NO₃) [(C₆H₅)₃ Sn^IV], containing a tin(IV)tin(II) bond, has been prepared, and its crystal structure is determined.     

Potentiometric stripping analysis for tin with a gold film electrode formed in situ on glassy carbon

A gold film electrode formed in situ on glassy carbon is used as the working electrode for the determination of tin over the range 0.1–10 μg ml^?1. Gold(III) added to the solution provides the film and serves as the oxidant for stripping. Two stripping curves corresponding to Sn(Au) → Sn(II) and Sn(II) → Sn(IV) were observed; either can be used for determinations of tin. The equations for the transition time (i.e., stripping signal) and stripping curve derived were verified experimentally.