摘要:
A novel organotin complex [(o-Cl-PhCH2)3SnOCOC 10H8N]·0.5C6H6 has been synthesized, and its crystal structure was determined by X-ray diffraction. The crystal belongs to monoclinic, space group C2/c with a = 1.6214(5), b = 1.2033(3), c = 3.2873(10) nm, β = 91.467(5)°, V = 6.411 (3) nm 3, Mr = 1441.26, Z = 4, Dc = 1.493 g/cm 3, μ(MoKα) = 10.79 cm-1, F(000) = 2904, R = 0.0500 and Rw = 0.0884. The bond lengths of Sn-C are 0.2150(5), 0.2157(4) and 0.2164(4) nm, and that of Sn-O is 0.2043(3) nm. The tin atom adopts a distorted tetrahedral geometry.
摘要:
The title complex [^nBuSn(O)(tsglyO)]6·6CHCl3 (tsglyO=N-p-tolysulfonyl-glycinate monoanion) was synthesized by the reaction of ^nBuSn(O)OH with N-p-tolysulfonyl-glycine in 1:1 molar ratio. The complex was characterized by IR, ^1H NMR spectra and elemental analysis. The crystal structure was determined by X-ray diffraction method. It crystallizes in rhombohedral system with space group R3. The crystal data are: a=b=2.738 7(4) nm, c= 1.446 5(4) nm, α=β=90°, γ=120°, Z=6, Dc=1.726 g·cm^-3, F(000)=4 878, V=9.396(3) nm^3, R1=0.032 5, wR2=0.0898. The structure shows a distorted octahedral configuration with six-coordination for the central tin atom. CCDC: 274183.
关键词:
lanthanum;ytterbium;amino acid;solution calorimetry;standard enthalpy of formation
摘要:
In order to obtain the standard molar enthalpies of formation of Rare-Earth amino acid coordination compounds, precise isothermal solution-reaction calorimetric method was used. The value of Δ<sub>r</sub>H<sub>m</sub><sup> [circled minus] </sup> of two coordination reactions was determined at T = 298.2 K. From the experimental results and other auxiliary values, the standard molar enthalpies of formation of Ln(Gly)<sub>5/2</sub>(Ala)<sub>3/2</sub>(ClO<sub>4</sub>)<sub>3</sub> ·H<sub>2</sub>O(s) [Ln = La, Yb] at T = 298.2K were obtained. The values of them is to be Δ<sub>r</sub>H<sub>m</sub><sup> [circled minus] </sup> [ La(Gly)<sub>5/2</sub>(Ala)<sub>3/2</sub>(ClO<sub>4</sub>)<sub>3</sub> ·H<sub>2</sub>O(s)] = -3545.45 kJ/mol and Δ<sub>r</sub>H<sub>m</sub><sup> [circled minus] </sup> [ Yb(Gly)<sub>5/2</sub>(Ala)<sub>3/2</sub>(ClO<sub>4</sub>)<sub>3</sub> ·H<sub>2</sub>O(s)] = -3793.81 kJ/mol, respectively.
摘要:
The corrosive electrochemistry of jamesonite was studied by cyclic voltammetry. Every peak in voltammograms was identified through thermodynamic calculation. The results show an irreversible electrode process by the strong adsorption of oxidation elemental sulfur on jamesonite. A deficient-metal and sulfur-rich compound is formed under the potential of 80 mV at pH 6.86. The passive action by elemental sulfur occurs from 80 to 470 mV and S2O23- , SO24- are produced at potential over 470 mV. The anodic peak producing SO24- is inhibited due to the deposition of PbSO4 at higher potential in Na2SO4 solution. The corrosive action of jamesonite becomes strong and the redox characterization similar to PbS, FeS and Sb2 S3 appears at pH 9.18.
摘要:
A novel method was described for the determination of ultra trace amount of scandium based on the cathodic adsorptive voltammetry of the mix-polynuclear complex of scandium-calcium-alizarin red S at a carbon paste electrode (CPE). The 2nd-order derivative linear scan voltammograms of the adsorbed complex were recorded by model JP - 303 polarographic analyzer from 0.0 to -1.0 V (vs. SCE). The experimental conditions of the working procedure were optimized. The results show that the complex can be adsorbed on the Surface of the CPE, yielding one peak at - 0.61 V, corresponding to the reduction of the alizarin red S in the mix-polynuclear complex at the electrode. The detection limit of Sc3+ is 1.0 x 10(-10) mol center dot L-1 for 3 min of accumulation time. The procedure was successfully applied to the determination of trace amount of scandium in the sample ores.
摘要:
Bioimaging with luminescent nanoparticle probes have recently attracted widespread interest in biology and medicine. In comparison with commonly used organic dyes, luminescent nanoparticles are better in terms of photostability and sensitivity. These optical features of nanoparticle probes are critical for real time tracking and monitoring of biological events in the cellular level, which may not be accomplished using regular fluorescent dyes. Nanoparticle probes are also shown highly suitable for immunoassay and other diagnostic and therapeutic applications. In this article, we describe a variety of optical nanoparticle probes such as quantum dots, metal nanoparticles, dye-doped nanoparticles etc. for bioimaging applications.
摘要:
The corrosive electrochemistry of jamesonite (Pb4 FeSb6 S14) was studied by the electrochemical methods of cyclic voltammetry, polarization, and AC impedance. The electrochemical processes of jamesonite were controlled by the corrosive reactions, growth of the metal-deficient and sulfur-riched layer, passivation and breakdown of elemental sulfur film on the electrode surface. The corrosive potential(ψcorr) moves negatively, its corrosive current increases, and hydroxyl action becomes stronger with the rising pH value. The charge transfer resistance increases and the capacitance decreases due to the gradual growth of the metal-deficient and sulfur-riched layer on the mineral surface from -378 to 122 mV (vs SHE). Element sulfur layer is formed at the potential of 122 mV. The charge transfer resistance increases and its capacitance rises slowly due to the gradual breakdown of sulfur film at voltage from 222 mV to 422 mV. S2O2-3 and SO2-4 ions occur when the electrode potential is over 422 mV. Under basic condition, the hydrophobic hydroxyl precipitate occurs on jamesonite surface, so that its collectorless floatability is poor. Under the condition of pH 6.86, it can be deduced that the potential range of collectorless floatability of jamesonite is from 22 to 422 mV due to the passive action of the hydrophilic sulfur on jamesonite surface, and its optimum range of floatable potential is between 122 and 322 mV.