气相色谱-质谱法测定木制品中双三丁基氧化锡

提出了气相色谱-质谱法测定木制品中双三丁基氧化锡(TBTO)含量的方法。样品经甲醇提取,所得提取液用四乙基硼化钠衍生化,产物用气相色谱-质谱法测定,外标法定量。双三丁基氧化锡的质量浓度在0.1～40 mg.L-1范围内与峰面积呈线性关系,方法的检出限(3S/N)为0.05mg.kg-1。在3个标准加入水平下进行了回收率和精密度试验,加标回收率在88.4%～90.4%之间,相对标准偏差(n=6)在2.0%～5.4%之间。     

Bis(tributyltin) oxide as a wood preservative: Its chemical nature in timber

Tributyltin compounds have been used for many years as wood preservatives. This study has provided, for the first time, an explanation for the previously reported dealkylation and/or volatilization of the tributyltin species in, and from, timber. Thus ¹¹⁹Sn NMR studies have shown that, on impregnation into timber, bis(tributyltin) oxide, (Bu₃Sn)₂O, is rapidly converted to other tributyltin species, Bu₃SnOX, and that these subsequently undergo disproportionation to Bu₄Sn and Bu₂Sn(OX)₂ compounds. We have additionally demonstrated that Bu₄Sn, so produced, is not persistent in timber and is lost by volatilization. Since the rate of disproportionation of the Bu₃SnOX species should be dependent upon the nature of the X group, it should be possible to affect significantly, if not to stop, this process by the use of alternative tributyltin fungicides, e.g. tributyltin methanesulphonate. However, tributyltin fungicides have been used successfully in wood preservation for at least 25 years. Therefore, it must be concluded that, even after disproportionation in timber, in service, sufficient preservative action is retained to prevent decay of wood under the conditions of natural exposure.     

Hitting a Soft Drug with a Hard Nucleophile: Preparation of Esmolol's Metabolite by Treatment with Bis(tributyltin) Oxide

A facile method for the production of esmolol's metabolite in high purity is described. Bis(tributyltin) oxide is used to disrupt esmolol's ester linkage, and hydrolysis is completed by addition of water, which also allows the inorganic side products to be conveniently extracted into ether. Evaporation of the aqueous phase and trituration with ethyl acetate provides the carboxylic acid–amine internal salt as a white, free-flowing powder.     

Effects of tributyltin(IV) chloride on fertilization of Styela plicata (Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy studies

The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm–egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.     

Effects of sublethal levels of tributyltin chloride on a new toxicity test organism,Liza saliens (osteichthyes,mugilidae): a histological study

The histopathological effects of 10^?7 and 10^?9 M tributyltin(IV)chloride,TBTCl, solutions on different Liza saliens organs have been studied by light microscope. The fish were sacrificed after 3–4 h incubation in 10^?7 M TBTCl solution or after 15 days incubation in 10^?9 M solution. The observed histopathological changes were dose‐ and time‐dependent. The 10^?7 M TBTCl concentration resulted in major damage to the gill epithelium, indicating that TBTCl primarily interfered with the respiration, osmoregulation, acid balance and nitrogenous waste excretion processes. After incubation in 10^?9 M TBTCl solution the fish lived 20 or more days, but many of the organs were altered. Thymus atrophy, reduced spleen and altered head kidney were observed. These histological results indicated that TBTCl interfered with organ immunodefense and altered main metabolic pathways in Liza saliens. The presence of melano‐macrophage centers, only in TBT‐treated liver and spleen, can be considered a tool to facilitate, with other biomarkers, the detection of alterations by toxicants. Regarding the pancreas activity in 10^?7 M solutions, it has been noted that, in the exocrine cells, very few zymogen granules were still present and the Langerhans islets were more altered. In 10^?9M solution the exocrine pancreatic cells had no granules and the islet cells presented degenerative alterations. In addition, TBTCl, which altered the pancreas and gonad morphology, could again be considered an endocrine disrupter even if biochemical data are still necessary. Finally, the Liza saliens juveniles could be considered an interesting biological model for experiments with contaminants, due to their ease of adaptation to experimental conditions and food chain position. Copyright © 2005 John Wiley & Sons, Ltd.     

Biodegradation of bis(tri-n-butyltin) oxide

Bis(tri-n-butyltin) oxide can be biodegraded by a mixed bacterial culture from activated sludge in cyclone fermentors under aerobic and anaerobic conditions with half-lives of five and three days respectively. The degradation follows a sequential dealkylation process. All the intermediates and end products are determined in the degradation process for mass balance calculation. Degradation under different nutrient conditions has been investigated. Adsorption losses for each of the butyltin and inorganic tin species on container walls have also been assessed and discussed.     

Organometallic complexes with biological molecules. XV. Effects of tributyltin(IV)chloride on enzyme activity,Ca2+, and biomolecule and synthesis in Ciona intestinalis (Urochordata) ovary

Considerable attention has been given in recent years to the possibility that xenobiotics in the environment may affect reproduction in animals. In this study, the relative impact of tributyltin(IV) (TBT) chloride, one of the most toxic environmental pollutants, was investigated using Ciona intestinalis ovary as a model system. The pleiotropic effects of TBT exposure are concentration dependent and include a decrease of ATP levels, lipid content and nucleic acid content and synthesis. In contrast, a marked increase in calcium (Ca²⁺) and glucose content is observed. Furthermore, TBT alters enzymatic activity, inhibiting creatine kinase and stimulating alkaline phosphatase and cholinesterase (at concentrations higher than 10^?5M in sterile sea water solution). The implications of these effects on reproduction and embryonal development are discussed, along with the possibility that they reflect an extreme cellular defence mechanism triggered to avoid deleterious consequences for the survival of the species.Copyright © 2001 John Wiley & Sons, Ltd.     

Effects of tributyltin(IV) chloride exposure on early embryonic stages of Ciona intestinalis: In vivo and ultrastructural investigations

The effects of tributyltin(IV) chloride (TBT chloride) solutions on ascidian embryos of Ciona intestinalis have been tested at different stages of development. It has been observed, in vivo, that TBT chooride inhibited cleavage of fertilized eggs and of embryo blastomeres giving rise to cellular masses that are not delimited by plasma membrane. Electron-dense precipitates of TBT chloride, probably as inorganic tin, have been observed by transmission electron microscopy in the egg cytoplasm of cellular masses. The same type of precipitate was present also inside the mitochondria, whose structure appeared to be highly modified. These ultrastructure aspects are indicative of a degenerative process of the embroys after incubation in TBT chloride.     

Effects of tributyltin(IV) chloride on the gametes and fertilization of Ascidia malaca (Ascidiacea: Tunicata)

Ascidia malaca gametes before fertilization incubated in 10^?5 or 10^?7 M solutions of tributyltin(IV) chloride, TBTCl, for 3 h appear highly damaged under transmission electron microscopy observation. Also, the fertilization process is affected by the compound: the damaged spermatozoa are present in the vitelline coat and the egg does not cleave. An increase of microbodies, structurally similar to peroxisomes, have been detected in the egg peripheral cytoplasm, probably in relation to their role in alleviating damage to some cellular components. The results have shown that the reproduction of ascidians under unfavourable environmental conditions is prevented. Copyright © 2003 John Wiley & Sons, Ltd.     

Stereospecific preparation of symmetrical (1Z, 3Z)- and (1E, 3E)-2,3-difluoro-1,4-disubstituted-buta-1,3-dienes from 1-bromo-1-fluoroalkenes

A straightforward method to prepare symmetrical (1Z, 3Z)- and (1E, 3E)-2,3-difluoro-1,4-disubstituted-buta-1,3-dienes is described. High E/Z ratio 1-bromo-1-fluoroalkenes, prepared by isomerization from the E/Z ≈ 1:1 isomeric mixtures, reacted with Bu₃SnSnBu₃ and Pd(PPh₃)₄ to afford (1Z, 3Z)-2,3-difluoro-1,4-disubstituted-buta-1,3-dienes in good yield. (Z)-1-Bromo-1-fluoroalkenes, which were prepared by kinetic reduction from 1-bromo-1-fluoroalkenes (E/Z ≈ 1:1), can undergo similar reaction with Bu₃SnSnBu₃ and Pd(PPh₃)₄/CuI to prepare (1E, 3E)-2,3-difluoro-1,4-disubstituted-buta-1,3-dienes.     

Kristallstruktur-Untersuchungen von Bis(pentafluorphenyl)tellurdihalogeniden (C6F5)2TeHal2 (Hal = Cl,Br)

Crystal Structure Determinations of Bis(pentafluorophenyl)tellurium Dihalides (C₆F₅)₂TeHal₂ (Hal = Cl, Br) Bis(pentafluorophenyl)telluriumdichloride and bis(pentafluorophenyl)telluriumdibromide crystallize at 10°C or 20°C from CH₂Cl₂ or CHCl₃ solution in the monoclinic space group P2₁/c with a = 649.5(1) pm, b = 1 275.6(2) pm, c = 1 816.2(5) pm, β = 92.89(2)° for (C₆F₅)₂TeCl₂ and a = 694.4(1) pm, b = 1 579.1(2) pm, c = 1 423.4(1) pm, β = 90.22(2)° for (C₆F₅)₂TeBr₂ with four formula units per each unit cell.     

Photocatalytic degradation of chloroform by bis (bipyridine)dichlororuthenium(III/II)

Broadband (λ > 320 nm) irradiation of chloroform solutions of either [Ru(bpy)₂Cl₂] or [Ru(bpy)₂Cl₂]Cl exposed to air led to a photostationary state, in which [Ru(bpy)₂Cl₂]⁺ predominated, and to the continuous decomposition of CHCl₃, as evidenced by the accumulation of HCl, hydroperoxides (CCl₃OOH and CHCl₂OOH), and tetra-, penta-, and hexachloroethane. The addition of Cl^? increased the rate of photodecomposition, while the replacement of Cl^? by F^? greatly decreased the rate. The observations are consistent with a photocatalytic cycle in which [Ru(bpy)₂Cl₂]⁺ is photochemically reduced to [Ru(bpy)₂Cl₂], which is thermally reoxidized by CCl₃OO or CCl₃OOH. In the absence of air a much slower photodecomposition reaction takes place leading to continuously increasing concentrations of chloroethanes. The data are consistent with a catalytic cycle in which [Ru(bpy)₂Cl₂]⁺ is photoreduced, as in aerated solutions, while [Ru(bpy)₂Cl₂] is photooxidized with chloroform as the substrate.     

C28X4（X=H,Cl）,CX4（X=H,Cl）的结构和电子光谱的理论研究

用ＩＮＤＯ法对Ｃ２８Ｘ４（Ｘ＝Ｈ，Ｃｌ）和ＣＸ４（Ｘ＝Ｈ，Ｃｌ）进行几何构型优化，得到Ｔｄ对称性的构型Ｃ２８Ｘ４有４种键、４种不等同原子，基态为稳定的闭壳层分子，以此构型为基础计算了上述分子的电子光谱，并预测Ｃ２８Ｘ４的电子光谱。     

Pd2X2(dpm)2(X＝NCO-,CH3CO2-,SCN-,NO3-;dpm＝Ph2PCH2PPh2配合物与H2S反应的NMR研究

采用NMR方法考察了室温和低温(-78～60℃)下Pd₂X₂(dpm)₂(X=NCO^-,CH₃CO₂^-,SCN^-和NO₃^-,dpm=Ph₂PCH₂PPh₂)与H₂S在CD₂Cl₂或CDCl₃中的反应。结果表明,在X=NCO^-和CH₃CO₂^-的情况下,H₂S优先与这些Pd配合物的阴离子作用生成相应的共轭酸HX和Pd₂(SH)₂(dpm)₂,后者在H₂S存在下又进一步转化为Pd₂(SH)₂(dpm)₂(μ-S);当X=SCN^-和NO₃^-时,反应则生成结构可能为[Pd₂(H)(SH)(μ-SH)(dpm)₂]⁺的双核Pd配合物。     

Die Gadoliniumcarbidhalogenide Gd4C2X3 (X = Cl,Br)

The Gadolinium Carbide Halides, Gd₄C₂X₃ (X = Cl, Br) The compounds Gd₄C₂X₃ (X = Cl, Br) and Tb₄C₂Br₃ have been prepared by reaction of the metals (RE), REX₃, and C in sealed Ta capsules at 1 100° and 1 300°C, respectively. Monophasic samples of Gd₄C₂Br₃ and Tb₄C₂Br₃ were obtained by reacting stoichiometric mixtures of the starting materials for five days. The needle shaped crystals are bronze-coloured and sensitive to air and moisture. Gd₄C₂X₃ crystallizes in the space group Pnma (No. 62) with lattice constants a = 1 059.6(4), b = 368.4(1), c = 1 962.7(8) pm (Gd₄C₂Cl₃), a = 1 084.4(1), b = 373.0(1), c = 2 036.1(1) pm (Gd₄C₂Br₃). According to Guinier photographs, Tb₄C₂Br₃ is isotypic (a = 1 074.3(2), b = 370.6(1), c = 2 019.4(1) pm). In the crystal structure C is octahedrally coordinated by Gd. The Gd₆ octahedra are linked via common edges to form corrugated layers. The X-anions coordinate all free edges and corners of these layers and connect them via Xⁱ? Xⁱ contacts parallel [001]. Gd₄C₂Br₃ shows metallic conductivity. The magnetic susceptibility follows at high temperatures a Curie Weiss law with an effective moment of 7.95 μ_B. At temperatures below 50 K antiferromagnetic order is observed.     

Solid-state 207Pb NMR studies of mixed lead halides, PbFX (X=Cl, Br, or I)

Solid-state 207Pb NMR studies have been conducted on mixed lead(II) halides of the type PbFX, where X=Cl, Br, or I. NMR data for the mixed halides are compared to the solid-state NMR data for the divalent, binary lead halides, PbX2 (X=F, Cl, Br, I). The NMR data are evaluated in the context of the structures of the compounds and the effects of the mixed halides on the electronic structure of the divalent lead. Data sets for the mixed halides are discussed and compared to those for the regular lead(II) halides.     

Effects of tri‐n‐butyltin (IV) chloride on neurulation of Ciona intestinalis (Tunicata,Ascidiacea): an ultrastructural study

This paper reports the cytotoxic effects of tri‐n‐butyltin (IV) chloride, TBTCl, on the neurulation process of the ascidian Ciona intestinalis. Exposure of the embryos at early neurula stage in 10^?5 and 10^?7 M TBT (IV) chloride solutions for 1–2 h provoked the irreversible arrest of their development. Morphological and ultrastructural observations suggested that most probably there are two principal causes determining the neurulation process block. The first is due to the TBT effects of inhibiting the polymerization and/or degradation of microfilaments and microtubules, proteins that constitute the cytoskeleton. The lack of orientation and extension of both microtubules and microfilaments of actin prevent the shape changes and mobility of neural plate blastomeres indispensable to the neurulation process. The second cause is certainly determined by the ultrastructural modification which mitochondria undergo. The ultrastructural anomalies showed by these organules are so serious as to impede their proper functionality with consequent inhibition of oxidative phosphorylation and ATP synthesis, remarkable metabolic processes that occur during ascidian neurulation. Copyright © 2005 John Wiley & Sons, Ltd.     

[NiL2X2] oder [HL][NiLX3] – Reaktion sterisch anspruchsvoller Trialkylphosphine L mit NiX2 (X = Cl,Br) in Ethanol

[NiL₂X₂] or [HL][NiLX₃] – Reaction of Sterically Demanding Trialkylphosphines L with NiX₂ (X = Cl, Br) in Ethanol The reaction of some sterically demanding trialkylphosphines L = PR₂R′ (R = ⁱPr, R′ = ^tBu; R = ^tBu, R′ = ⁱPr, Me) with NiX₂ (X = Cl, Br) in ethanol affords instead of the expected non-electrolytes [NiL₂X₂] tertiary phosphonium nickelates [HL][NiLX₃] due to participation of the solvent. In case of the less bulky P^tBu₂Me both complex types were obtained. [Ni(P^tBu₂Me)₂Cl₂] is tetrahedral and therefore one of the two examples of paramagnetic bis(trialkylphosphine)dihalogenonickel(II) complexes known so far. In solution the latter compound undergoes an equilibrium of tetrahedral (paramagnetic) and planar (diamagnetic) conformer. Vis spectra as well as the results of magnetic measurements and ¹H and ³¹P NMR investigations are reported.     

Tetramethylcyclotetraarsoxane Bridged Copper(I) Halides with Porous Sheet and Framework Structures [CuX{cyclo-(MeAsO)4}] (X=Cl,Br, I) and [Cu3X3{cyclo-(MeAsO)4}2] (X=Cl,Br)

Open sheet and framework structures [CuX{cyclo-(MeAsO)₄}] (X=Cl, Br, I) 1 – 3 and [Cu₃X₃{cyclo-(MeAsO)₄}₂] (X=Cl, Br) 4 and 5 may be prepared by self-assembly from CuX and methylcycloarsoxane (MeAsO)_n in acetonitrile solution. 1 – 3 exhibit 4⁴ nets in which (CuX)₂ units are connected through μ-1 _KAs¹ : 2 _KAs³ coordinated (MeAsO)₄ ligands into large 28-membered rings. In contrast, adjacent [CuX] chains in 4 and 5 are connected into sheets by μ₄-K⁴ As coordinated (MeAsO)₄ building blocks, with μ-1 _KAs¹ : 2 _KAs³ bridging of these layers by independent (MeAsO)₄ cyclotetramers leading to the generation of a porous framework structure. 1 – 5 were characterised by X-ray structural analysis.