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1
Clarke, David John. „Organotin compounds for catalysis“. Title page, abstract and contents only, 2001. http://web4.library.adelaide.edu.au/theses/09SM/09smc5974.pdf.
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2
Hill, Michael Stephen. „Organotin tetrazoles and related compounds“. Thesis, University of Bath, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240694.
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3
Kuan, Fong Sheen, und mikewood@deakin edu au. „Organotin-Oxo Clusters“. Deakin University. School of biological and chemical sciences, 2002. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20051125.084244.
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This thesis reports on the development and expansion of reliable synthetic di-and multi-tin precursors for the assembly of oligomeric organotin-oxo compounds in which the shape, dimension and tin nuclearity can be controlled.
The reaction of polymeric diorganotin oxides, (R2SnO)m (R = Me, Et, n-Bu, n-Oct, c-Hex, i-Pr, Ph), with saturated aqueous NH4X solutions (X = F, Cl, Br, I, OAc) in refluxing 1,4-dioxane afforded in high yields dimeric tetraorganodistannoxanes, [R2(X)SnOSn(X)R2]2, and in a few cases diorganotin dihalides or diacetates, R2SnX2. This method appears to be particularly good for the synthesis of halogenated tetraorganodistannoxanes but a less suitable method for the preparation of dicarboxylato tetraorganodistannoxanes. Identification of [R2(OH)SnOSn(X)R2]2 (R = n-Bu; X = Cl, Br) and [R2(OH)SnOSn(X)R2][R2(X)SnOSn(X)R2] suggest a serial substitution mechanism starting from [R2(OH)SnOSn(OH)R2]2.
A series of α, ω -bis(triphenylstannyl)alkanes, [Ph3Sn]2(CH2)n (n = 3-8, 10, 12) and some of their derivatives were synthesised and characterised. These α, ω-bis(triphenylstannyl)alkanes, [Ph3Sn]2(CH2)n were converted to the corresponding halides [R(Cl)2Sn]2(CH2)n (R = CH2SiMe3) and subsequently to the polymeric oxides {[R(0)Sn]2(CH2)n}m. Reaction of {[R(O)Sn]2(CH2)n}m with [R(Cl)2Sn]2(CH2)n. (n = 3, n' = 4 and n = 4, n' = 3) in toluene at 100°C results in a mixture of symmetric and asymmetric double ladders, where different spacer chain lengths (n and n') provide the source of asymmetry. The coexistence at high temperature of separate 119Sn NMR signals belonging to symmetric and asymmetric double ladders suggests an equilibrium that is slow on the 119Sn NMR time scale and the position of which is temperature dependent. However, 119Sn NMR spectroscopic experiments of {[R(0)Sn]2(CH2)3}m with [R(Cl)2Sn]2(CH2)n for longer spacers (n - 5, 6, 8, 10, 12) reveal that molecular self-assembly of symmetric spacer-bridged di-tin precursors of equal chain length is preferred over asymmetric species.
An ether-bridged di-tin tetrachloride [R(Cl)2Sn(CH2)3]2O (R = CH2SiMe3) and its corresponding polymeric oxide {[R(O)Sn(CH2)3]2O}m were synthesised and characterised. Reaction of [R(Cl)2Sn(CH2)3]2O with {[R(O)Sn(CH2)3]2O}m results in a unique functionalised double ladder {{[RSn(Cl)](CH2)3O(CH2)3[RSn(Cl)]}O}4 whose structure in the solid state was determined by X-ray analysis. Identification of tetrameric functionalised double ladder as well as dimeric and monomeric species suggest the existence of an equilibrium in solution. The feasibility of the functionalised double ladder to form host-guest complexes with a variety of metal cations is investigated using electrospray mass spectrometry (ESMS). Evidence for such complexes is found only for sodium cations.
The reaction between {[R(O)Sn]2(CH2)n}m (n = 3, 4, 8, 10) and triflic acid is described. The initial formed products [RSn(CH2)nSnR](OTf)4 are easily hydrolysed. For n = 3, self-assembly leads to a discrete double ladder type structure, {{[RSn(OH)](CH2)3[RSn(H2O)]}O}44OTf, which is the first example of a cationic double ladder. For n ≥ 3, hydrolysis gives polymeric products, as demonstrated by the crystal structure of {[(H2O)(OH)RSn]2(CH2)4-2OTf2H2O}m.
Two spacer-bridged terra-tin octachlorides [R(Cl)2Sn(CH2)3Sn(Cl)2]2(CH2)n (R = CH2SiMes; n = 1, 8) and their corresponding polymeric oxides {[R(O)Sn(CH2)3Sn(O)]2(CH2)n}m were successfully synthesised and characterised. Attempts were made to synthesise quadruple ladders from these precursors. Reactions of [R(Cl)2Sn(CH2)3Sn(Cl)2]2CH2 with {[R(O)Sn(CH2)3Sn(O)]2CH2}m or (Y-Bu2SnO)3 result in, mostly insoluble, amorphous solids. Reactions of [R(Cl)2Sn(CH2)3Sn(Cl)2]2(CH2)8 with {[R(O)Sn(CH2)3Sn(O)]2(CH2)8}m or (t-Bu2SnO)s result in new tin-containing species which are presumably oligomeric.
The synthesis of a series of alkyl-bridged di-tin hexacarboxylates [(RCO2)3Sn]2(CH2)n (n = 3, 4; R = Ph, c-C6H11, CH3, C1CH2) is also reported. The hydrolysis of these compounds is facile and complex. There appears to be no correlation between spacer chain length and hydrolysis product. However, the conjugate acid strength of the carboxylate does appear to be important. In general only insoluble amorphous polymeric organotin-oxo compounds were obtained.
4
Al-Rawi, Mustafa. „Halogenation of sterically hindered organotin compounds“. Thesis, University of Sussex, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310661.
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5
Chatterjee, Debesh Kumar. „Arylazo phenoxy derivatives of organotin compounds“. Thesis, University of North Bengal, 1990. http://hdl.handle.net/123456789/757.
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6
Ross, Jennifer Nicola. „Alkoxy- substituted aryl- and benzyl- organotin compounds“. Thesis, University of Aberdeen, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324880.
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New organotin compounds containing alkoxy- functionalities have been prepared. The methods of preparation of the tetraorganotin species have involved three routes. Hydrostannation reactions using triphenyltin hydride have resulted in the synthesis of triphenyltin derivatives of a series of alkoxy- substituted allyl ethers. The addition of tin IV chloride, diphenyltin dichloride and phenyltin trichloride to alkoxy- substituted aryl- and benzyl- Grignard reagents have also been successful. Alkoxy- substituted benzyltin compounds have been prepared by following an alternative preparation of benzylmagnesium halides from that commonly used to prepare Grignard reagents. Nucleophilic substitution of (iodomethyl)triphenyltin by a novel ligand has been effective. The structures of the products have been investigated by 1H, 13C and 119Sn nmr. Single crystal X-ray diffraction studies have led to the determination of the crystal structures of tetra-2-anisyltin, tetrakis-(2-methoxybenzyl)tin and N,N'-bis(5-triphenylstannoxymethyl-2-phenyl-1,3-dioxan-5-yl)ethanediamide. Selective tin-carbon bond cleavage has been effected by the use of iodine and bromine to give rise to mono- and dihalo- organotin compounds and the crystal structures of tri-2-anisyltin iodide and di-2-anisyltin dibromide have been elucidated by X-ray crystallography. Chloro(3-ethoxypropyl)diphenyltin has been synthesised directly from diphenyltin dichloride and has been found to contain a penta-co-ordinate tin centre with a four membered chelate ring as a result of intramolecular tin-oxygen co-ordination. Other tin-carbon bond cleavage reactions by halogens have been studied by 1H and 119Sn nmr and GLC and the results discussed.
7
Deb, Chaitali. „Preparation and reactions of some organotin compounds : applications to organic synthesis“. Thesis, University of North Bengal, 1993. http://hdl.handle.net/123456789/759.
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8
Doidge-Harrison, Solange Maria Silva Veloso. „X-ray and spectroscopic studies of organotin compounds“. Thesis, Robert Gordon University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304984.
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9
O'Loughlin, Edward John. „Association of organotin compounds with aquatic humic substances /“. The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487946776023338.
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10
Baguley, Paul A. „Search for practical alternatives to organotin hydrides“. Thesis, University of St Andrews, 1998. http://hdl.handle.net/10023/15419.
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A summary of the tin hydride method of generating radicals in organic synthesis is presented, followed by illustrative examples of other methods available for mediating radical reactions, with a particular emphasis on recent developments. This is followed by four chapters describing our efforts to introduce alternative methods for generating radicals. A range of l-alkylcyclohexa-2,5-diene-l-carboxylic acids have been prepared by Birch reduction-alkylation methodology and shown to generate the corresponding alkyl radical by thermal initiation with dibenzoyl peroxide. The 1-benzyl, cyclopentyl and t-butyl precursors (17,15, and 16 respectively), acted as sources of radicals which were trapped with cyclohexenone to give the corresponding 3-alkylcyclohexanone adducts in yields of 52%, 30% and 25% respectively. Addition products were also observed when acrylonitrile and vinyl benzoate were employed as the radical traps. 1-[2-(Cylohex-2-enyloxy)ethyl]cyclohexa-2,5-diene-l-carboxylic acid 32 and l-[2-(6,6- dimethylbicyclo[3.1. l]hept-2-en-2-ylmethoxy)ethyl]cyclohexa-2,5-diene- 1-carboxyhc acid 33 are new compounds which were prepared in four straightforward steps from cyclohexene and β-pinene respectively. The route leading to acid 32 involved the preparation of four new compounds and three new compounds were prepared during the synthesis of acid 33. When refluxed in benzene in the presence of dibenzoyl peroxide, carboxylic acid 32 generated a primary alkyl radical which cyclised to yield 7- oxabicyclo[4.3.0]-nonane in 55% yield. The tin-mediated cyclisation of 3-(2'- iodoethoxy)cyclohexene 36 yielded the same compound in 60% yield, in addition to 3- ethoxycyclohexene (12%). Similarly, carboxylic acid 33 generated a primary alkyl radical which cyclised to yield the new compound oxacyclopentane-3-spiro-2-6,6- dimethylbicyclo[3.1.1]heptane in 10% yield. The tin-mediated cyclisation of 6,6-dimethyl- 2-(2-iodoethoxymethyl)bicyclo[3.1.1]hept-2-ene 37 yielded the same spiro compound in 31% yield. EPR spectroscopic studies provided direct evidence for the formation of the cyclohexadienyl radicals from all of the carboxylic acids investigated. Carboxylic acids 15- 17 and l-[2-(ethenyloxy)benzyl]cyclohexa-2,5-diene-l-carboxylic acid 34 also generated alkyl radicals which were clearly observed by EPR spectroscopy. The carboxylic acid radical precursors would have yielded products in higher yields if the competitive loss of a hydroxyformyl radical did not occur. An account of our work directed towards the synthesis of l-phenylcyclohexa-2,5-diene-l- carboxylic acid 8 is given. Thus, 1,4-dihydrobiphenyl was deprotonated with BuLi, added to CO2 and the isomeric acid, 3-carboxylic acid-3,4-dihydrobiphenyl was removed by reacting with maleic anhydride to give the Diels-Alder adduct. 2-(Cyclohex-2-enyloxy)ethyl l-phenylcyclohexa-2,5-diene-l-carboxylate 24 was treated with dibenzoyl peroxide to afford 7-oxabicyclo[4.3.0]nonane in yields of 32-36%. A variety of N-carboalkoxy-l,2-dihydropyridines have been prepared from the reaction of pyridine and the appropriate chloroforniate in the presence of NaBH4. EPR studies have shown that these esters produce aza-cyclohexadienyl radicals on photolysis in the presence of di-t-butyl peroxide, but no decarboxylation was observed. These compounds do not generate alkyl radicals efficiently when reacted with dibenzoyl peroxide. In each case the major product identified was the corresponding benzoate ester, which resulted from the combination of an alkoxycarbonyl radical and a phenyl radical.
11
Björn, Annika. „Microbial Transformation of Organotin Compounds under Simulated Landfill Conditions“. Doctoral thesis, Linköpings universitet, Tema vatten i natur och samhälle, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10278.
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Mono- and di-alkyltins are used extensively as heat stabilizers for processing of poly vinyl chloride (PVC). Tin mercaptide stabilizers are some of the most effective PVC stabilizers available. The main applications for tin stabilizers are building/construction products, such as pipes, fittings, siding and profiles (windows etc.), packaging and flexible PVC plastics. Most PVC products have been and are subjected to landfilling, when their use is terminated. The structure of the polymer itself and the substances used as additives have been a concern for environmental authorities in many countries since long, which also includes their presence in landfills. In the case of the organotin stabilizers their leaching out from (PVC) plastics into the leachate phase of landfills with the risk for further transport to ground and surface waters is in focus. The main objectives of this thesis take their start in this background and, thus, included the elucidation of whether organotin compounds (OTs) in stabilized PVC products contribute to the pool of OTs observed in landfill leachates and if these compounds are degradable by the microorganisms developing under anaerobic landfill conditions. To reach these aims and the research questions raised the forwarded PVC materials were added to muniscipal solid waste (MSW) processed in containers used to simulate the ageing of landfills under forced conditions. These include traditional landfill simulation reactors (LSRs) at a scale of ca 100 L and also at a smaller scale ca 5 L constructed for the purpose of this study, i.e. the modular environmental test system (METS). The latter were used to investigate temperature effects on the possible release of OTs from different types of PVC materials. The capacity by microorganisms in landfill environments were used to investigate their capacity to degrade or transform organotin stabilizer compounds focused on in this thesis. Differences in this capacity in relation to the ageing of landfills and exposure to the alkyltin stabilizers were studied with microorganisms sampled from LSRs spiked with PVC over time and from landfill site. Access to sensitive and reliable equipment and analytical protocols for the analysis of OTs and their transformation intermediates and end products are prerequisites for this kind of studies. This necessitated an adoption and adaptation of analytical methods for the low concentrations occurring in the environment. Two methods were established and well served the requirements. Indeed OTs migrated out from especially flexible PVC materials, while rigid PVC was less prone for OT release as judged from the METS simulations. The METS studies showed that the OT release increase substantially at higher temperatures and especially so when the temperature was higher than the glass transition of the PVC.materials. The organotin stabilizers were transformed, partly or completely degraded, by anaerobic microorganisms derived from landfill environments. Upon prolonged exposure to OTs leaching from PVC in LSR simulations the microorganisms displayed a higher efficiency in degradation of the leached OTs. The microorganisms would methylate inorganic tin and metyltin present in the MSW material as well as perform dealkylation depending on the tin concentrations prevailing. During these studies it was discovered that the organotin stabilzers were inhibiting the methanogens and fermentative bacteria, which lead to a retardation of the anaerobic mineralisation of the MSW in the assays. An in depth study revealed that the OTs themselves but also their ligands and degradation products from these together effected the inhibition. However, given the extent of leaching in relation to the water flows in landfills, the concentrations will mainly be too low to pose any risks to the surrounding environment.
12
Ashby, J. R. „Formation and distribution of organotin compounds in the environment“. Thesis, De Montfort University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232890.
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13
Harino, Hiroya. „STUDIES ON BEHAVIOR OF ORGANOTIN COMPOUNDS IN AQUATIC ENVIRONMENT“. Kyoto University, 1998. http://hdl.handle.net/2433/157120.
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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・論文博士
博士(農学)
乙第9859号
論農博第2184号
新制||農||764(附属図書館)
学位論文||H10||N3168(農学部図書室)
UT51-98-G458
(主査)教授 中原 紘之, 教授 内田 有恆, 教授 大東 肇
学位規則第4条第2項該当
14
Athukorala, Arachchige Kasun S. „Synthesis and crystallographic studies of novel organotin acenaphthene compounds“. Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6363.
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Organic frameworks with rigid backbones, such as acenaphthene, are highly suitable for the study of interatomic interactions. The short “natural” peri-distance (2.44 Å) and the rigidity of the aromatic system causes considerable steric strain between peri-substituted heteroatoms. As a consequence, substitution at both peri-positions leads to in- and out-of-plane distortions, which often result in buckling of the ring system. In order to relax this geometric strain, weak bonding interactions can also exist between the peri-substituents. This thesis focuses on the synthesis, structural characterisation and investigation of a range of sterically crowded peri-substituted acenaphthene compounds. This involves the study of the acenaphthene geometry, through X-ray crystallography when different peri-substituents occupy the close 5,6-positions; our main focus is to study weak non-bonded interactions that can occur across the peri-gap, for example weakly attractive three-centre four-electron (3c-4e) type interactions which are known to prevail in such compounds under the appropriate conditions. Repulsion within these systems, resulting from the steric crowding of the peri-space is also investigated, employing changes in bond lengths, bay-region angle splay, displacement of atoms from the mean plane and central acenaphthene torsion angles to help quantify the degree of acenaphthene distortion, which are all conveniently probed by the peri-distance. To this end we have synthesised a range of novel sterically crowded mixed bromo-tin acenaphthene derivatives (Chapter 3), chalcogen-tin acenaphthene molecules (Chapter 4), phosphorus–tin derivatives (Chapter 5) and a series of homologous tin-tin acenaphthenes (Chapter 6). All the compounds studied in this thesis were characterised by multinuclear NMR spectroscopy and X-ray crystallography in an effort to gain a greater understanding of the deformation that occurs when disparate functionalities are located in close proximity and explore the potential for weak non-covalent intramolecular interactions to occur.
15
Björn, Annika. „Microbial transformation of organotin compounds under simulated landfill conditions /“. Linköping : Department of Water and Environmental Studies, Linköping University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10278.
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16
Brown, Paul. „The preparation and use of sterically hindered organotin compounds“. Thesis, University of Bath, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234639.
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17
Smith, Suzanne Watson. „Synthesis of tin(IV) complexes for use as potential catalysts for polyurethane formation“. Thesis, University of Warwick, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263805.
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18
Karanjai, Manju. „Organotin derivatives of carbonyl activated unsaturated organic compounds and their Lewis acid characters“. Thesis, University of North Bengal, 1989. http://hdl.handle.net/123456789/765.
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19
Dunn, Kerri, und kerri dunn@deakin edu au. „Chiral organotin hydrides as enantioselective reducing agents“. Deakin University. School of Nutrition and Public Health, 2000. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20061207.142326.
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This thesis reports on the feasibility of the utilization of organotin hydrides as enaantioselective free radical reducing agents. The chiral organotin hydrides prepared contain the bulky chiral (1R,2S,5R)-menthyl substituent and in some cases also contain a stereogenic tin centre. Reaction of (1R,2S,5R)-menthylmagnesium chloride (MenMgC1) with triphenyltin chloride in THF proceeds with epimerization of the C-1 carbon of the menthyl group and results in a mixture of (1R,2S,5R)-menthyltriphenyltin and (1S,2S.5R)-menthyltriphenyltin. Addition of Lewis bases such as triphenylphosphine to the THF solution of triphenyltin chloride prior to the addition of the Grignard reagent suppresses epimerization and enables isolation of pure (1R,2S,5R)-menthyltriphenyltin. (1R,2S,5R)-Menthyltriphenyltin is the precursor for the synthesis of (1R,2S,5R)-menthyldiphenyltin hydride as well as (1R,2S,5R)-menthyl-containing organotin halide derivatives. A crystal structure of (1R,2S,5R)-menthylphenyltin dibromide and (1R,2S,5R)-menthylphenyltin dichloride confirmed the configuration of the menthyl substituent in these compounds.
Reaction of MenMgC1 with diphenyltin dichloride in THF proceeds with no epimerization of the C-1 carbon of the menthyl group and bis((1R,2S,5R)-menthyl)diphenyltin is formed. A crystal structure of (1R,2S,5R)-menthyltriphenyltin confirmed the configuration of the menthyl substituent. Bis((1R,2S,5R)-menthyl)diphenyltin is used to form bis((1R,2S,5R)-menthyl)phenyltin hydride as well as other bis(1R,2S,5R)-menthyl derivatives.
A series of chiral non-racemic triorganotin halides and triorganotin hydrides containing one or two (1R,2S,5R)-menthyl substituents as well as various potentially intramolecular coordination substituents were synthesized and characterized. The intramolecular substituents include the 8-(dimethylamino)naphthyl, 2-[(1S)-1-dimethylaminoethyl]phenyl, 2-(4,4-dimethyl-2-oxazoline)-5-methylphenyl and the 2-(4-(S)isopropyl-2-oxazoline)-5-methylphenyl substituents.
Each compound containing a stereogenic tin centre was synthesized as diastereomeric mixtures. AM1 calculations of these compounds provide good qualitative predictability of the molecular geometries observed in the solid state as well as the diastereomeric ratios observed in solution. X-ray analysis of some of the organotin halides containing intramolecular coordination substituents revealed a tendency towards penta-coordination at the tin centre as a result of N-Sn interactions.
The chiral organotin hydrides synthesized were found to be poor enantioselective free radical reducing agents. However, the addition of one molar equivalent of achiral or chiral Lewis acids to the free radical reduction reactions involving these organotin hydrides results in remarkable increases in enantioselectivity. There are numerous examples in which enantioselectivities exceed 80% and three examples of enantioselectivites which are equal and above 90% with one outstanding enantioselective outcome of ≥99%. These results appear to be the highest enantioselectivites for organotin hydride radical reductions reported to date.
There is strong evidence to suggest that the chiral menthyl group of the organotin hydride directs the stereochemical outcome in the reduced product. The results also suggest that an increase in the number of menthyl substituents attached to tin or the introduction of intramolecular coordination substituents does not necessarily results in a greater increase in enantioselectivity.
Preliminary studies into the synthesis of organotin hydrides containing Lewis acid functionalities are also reported. A zirconium chloride functionality was found to be incompatible with organotin hydride. However, an organotin hydride containing a trialkylboron Lewis acid functionality attached via an alkyl chain was successfully synthesized. Although this reagent was only stable in the preparative THF solution, it was still found to be effective at reducing benzaldehyde to benzyl alcohol.
20
Turoczy, Nicholas John, und mikewood@deakin edu au. „Adsorption and voltammetry of butyltin compounds“. Deakin University, 1994. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050915.154112.
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The adsorption of tributyltin onto materials commonly used for the construction of sampling and analytical equipment from aqueous solutions of varying ionic composition has been examined. The adsorption appears to be controlled by non-polar interactions between tributyltin and the surface involved. Since the speciation and hence polarity of tributyltin is affected by the ionic composition of the medium, the extent of adsorption is affected by the salinity and pH of a sample. The adsorption is rapid and, unless strategies are adopted to eliminate its effects, may render analytical results invalid.
The electrochemistry of tributyltin, dibutyltin and monobutyltin, individually and in mixtures, has been investigated in aqueous media at mercury electrodes. The basic electrochemistry of each compound is summarised by the reaction
BunSn (4-n)+ + (4-n)e- right left harpoons BunSn
where n is the number of butyl groups attached to the tin atom. However, the electrochemistry of each compound is largely confined to the surface of the mercury electrode, and the simplicity of the above reaction is disrupted by polymerisation reactions and by butyl exchange processes occurring with the mercury electrode. When mixtures of butyltin compounds are present, the various processes that occur for each individual compound interfere with each other. A direct voltaminetric method for the determination of butyltin compounds in natural waters is therefore probably not possible.
21
Cheewasedtham, Wilairat. „Environmental fate of organotin compounds : a chemical and microbiological study“. Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340585.
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Environmental fate and exposure assessment of triphenyltin and its degradation products in soil has been studied by using both chemical and microbiological methods together. For the chemical method, phenyltin compounds were derivatised by ethylation with NaBEt4 before injection into GC-MS, and analysed under selected ion monitoring (SIM) mode. the extraction recovery of phenyltin components (TPhT and DPhT) in soil was greater than 85%. The detection limits of MPhT, DPhT and TPhT in aqueous solutions were found to be 0.2, 0.2 and 0.3 ng as Sn, respectively which gave the limit of determination for the method as 0.01 μg g-1 for both phenyltins in soils and sediments and butyltin in sediments. The in-situ ethylation was found to be one of the most powerful techniques for organotins in sediments as it is rapid, and reliable and no suppression by any organic content was found. The pH values of test solutions were found to affect the toxicity of phenyltin compounds to microbial biosensors as these factors may influence the hydrophobicity of the compounds. The toxicity order of TPhT, DPhT and MPhT to two luminescent bacterial biosensors was found to be different from that of the Microtox assay. DPhT was found to be the least toxic phenyltin compound to all biosensors while MPhT was found less toxic than TPhT when using lux-marked P. fluorescens, TPhT was found to be more toxic in aqueous solution than in soil extract, while the toxicities of DPhT and MPhT in aqueous and in soil extract were not significantly different. In an experiment that studied the degradation of TPhT acetate and its exposure over a period of 33 weeks, there was no degradation of TPhT in both autoclaved soils observed. The degradation pattern of TPhT was found to be a non-linear regression transformation in both spiked soils with half-life of TPhT as 26 and 20 days in non-sterile soils at 10 and 20 μg g-1, respectively. The toxicity of TPhT mixed with its degradation products has been found to decrease after 8 weeks, this represents only a sole application.
22
Skerlj, Renato Tony. „Synthesis and chemistry of alkyl 2, 3-bis(trimethylstannyl)-2-alkenoates and related substances“. Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29391.
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This thesis describes the synthesis and chemistry of alkyl 2,3-bis(trimethylstannyl)-2-alkenoates ((78) and (83)). It was shown that these compounds could be readily transformed into useful intermediates for the synthesis of functionalized, stereochemically defined tetrasub-stituted alkenes (87) and tricyclic dienes of general structure (322A).
The synthesis and chemistry of compounds (277) and (278) is also described.
The palladium(O)-catalyzed addition of hexamethylditin to a variety of α,β-acetylenic esters (90), afforded in a stereoselective manner, the corresponding alkyl (Z)-2,3-bis(trimethylstannyl)-2-alkenoates (83). Subsequent thermolysis of these compounds afforded the corresponding alkyl (E)-2 , 3-bis(trimethylstannyl)-2-alkenoates (78).
It was found that treatment of alkyl (E)- and (Z)-2,3-bis(tri-methylstannyl)-2-alkenoates with methyllithium at low temperature, followed by reaction of the resultant nucleophilic intermediate with a variety of alkylating agents, afforded the trisubstituted vinylstannanes (80). On the other hand, successive treatment of methyl w-halo-2,3-bis-(trimethylstannyl)-2-alkenoates (202) with methyllithium and HMPA provided a facile route to cyclic β-trimethylstannyl α,β-unsaturated esters (203).
Compounds (80) were readily converted into vinyl iodides of general structure (219) in which W is a functionalized group derived from the CO₂R moiety. These latter compounds served as useful intermediates for the synthesis of functionalized, stereochemically defined tetrasubstituted alkenes (87). For example, treatment of compounds (219) with 1.1 or 2.2 equiv of n-butyllithium at -78°C afforded the corresponding vinyllithium species (86) , which could either be alkylated directly or further transposed into the organocopper(I) reagent (263A) and then alkylated, to afford in each case, the tetrasubstituted alkenes (87).
The Pd(0)-catalyzed addition of tri-n-butylstannyltrimethylgermane (276) to a variety of α,β-acetylenic esters (90) afforded the corresponding
compounds (277) and (278) in a ratio of approximately 3:1, respectively. Treatment of the (E) isomers (277) with n-butyllithium at -98°C, followed by alkylation of the resultant nucleophilic intermediate afforded the corresponding trisubstituted vinylgermanes (293). One of these latter compounds was readily converted into the iodo bromide (308), which is potentially synthetically equivalent to the d,a synthon (310).
When the enolate anion of compounds (203) was successively treated with HMPA and compound (308) the esters (311) were obtained. The Pd(0) catalyzed intramolecular coupling of the vinylstannane-vinyl iodide moieties of (311) provided a facile route to the bicyclic triene esters (312). Similarly, alkylation of the enolate anion of compounds (203) with (325) (which was readily obtained from (203), in which n - 1), followed by the Pd(0)-catalyzed coupling of the resulting alkylated material afforded the tricyclic diene esters (322A). [Formula Omitted]Science, Faculty of
Chemistry, Department of
Graduate
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Sen, Sarma Moumita. „Organotin compounds : an investigation on the synthesis, structures and properties (including biocidal properties) of organotin carboxylates and related componds“. Thesis, University of North Bengal, 2007. http://hdl.handle.net/123456789/733.
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Taylor, Oonah J. „A study of c-stannylated monosaccharide derivatives“. Thesis, University of Aberdeen, 1988. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602280.
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A series of C-stannylated monosaccharide derivatives were prepared and their chemistry studied. Derivatives having a hydroxyl group ? to tin, i.e. methyl 4,6-0- benzylidene-2(3)-deoxy-2(3)-triphenylstannyl-?-D-allopyranosides [(1) and (2)] and 6-deoxy-l,2-0-isopropylidene-6-triorganostannyl-?-D-glucofuranose (3, R=Me, 4, R=Ph) were prepared by reaction of appropriate triorgano-tin-lithiums with epoxy sugars. Reactions of 3 with TFA, acetyl chloride, benzoyl chloride, ethyl chloroformate, sulphur dioxide and TCNE produced via elimination, 5,-6- dideoxy-1,2-0-isopropylidene-?-D-xylo-hex-5-enofuranose (15). Methyl-tin bond cleavage in 3, with formation of C-(dimethylhalogenostannyl)- monosaccharides, occurred on reaction with I2, Br2 or Pd(COD)Cl2. The product from the I2 reaction was unstable in solution and gave the elimination product 15. MeLi gave no reaction, and both SnCl4 and ClSO3H gave Me3SnCl and acetone as the only recognisable products. The triphenylstannyl derivatives 1, 2 and 4 underwent phenyl-tin cleavage with electrophiles. The 1,2:5,6-di-0-isopropylidene-3-C-(triorganostannyl)methyl-?-D-allofuranoses [R=Me, (11), Bu (12) or Ph (13)] were prepared by reaction of an appropriate (triorganostannyl)methy1-lithium with a keto-sugar. Substitution to form the C-(iodostannylated) monosaccharide occurred for all compounds on reaction with iodine. No elimination was obtained on reaction of 11 with TFA, deprotection being the predominant route. The elimination product was isolated from the attempted Pd-catalysed coupling of 12 with PhCOCl and from reaction of the methoxymethyl ether derivative 14 (R=Ph) with PhLi. No reaction was observed on treatment of 12 and 13 with organolithium reagents. Derivatives having a hydroxyl group ? to tin, the l,2:5,6-di-0- isopropylidene-3-C-triorganostannyl-?-D-allofuranoses [R=Me (9) and Ph (10)] were prepared via reaction of a triorganostanny1-lithium with a keto- sugar. Compound 9 gave predominant methyltin cleavage with I2, was partially deprotected by TFA and gave the methyl-coupled product, Me-R, on reaction with carbon electrophiles, R-Y, under Pd-catalysis. The triphenyltin derivative 10, decomposed on treatment with TFA, gave no reaction with phenyl-lithium and pheny1-tin cleavage with I2. The ?-alkoxy derivatives, l,2:5,6-di-0-isopropylidene-3-0-(triorgano-stannyl)methyl-?-D-glucofuranose [R=Me (5) and Ph (6)] and (triorgano-stannyl)methyl 2,3:5,6-di-O-isopropylidene-?-D-mannofuranoside [R=Me (7) and Ph(8)] were prepared via alkylation of a free hydroxyl by iodomethyl-triorganostannane. The triphenyl derivatives underwent pheny1-tin cleavage with I2 and TFA, while tin-lithium exchange occurred with PhLi to give a lithiated sugar which was trapped by a variety of reagents. Compounds 5 and 7 gave competitive cleavage of Me-Sn and R*OCH2-Sn bonds on treatment with halogens. Reaction with TFA, acetyl chloride and SO2 gave predominant reaction at the protecting groups and no reaction was observed for benzoyl chloride and ethylchlorofornate. Tin(IV) chloride gave mainly methyl transfer to tin to form MeSnCl3 and the C-chlorodimethylstannyl derivatives. Treatment with Pd(COD)Cl2 however, gave competitive transfer of methyl group and sugar moiety from tin to palladium. The crystal structures of 10, 13 and the iodo-derivative of 12 were determined; and the results of biological testing of 10 and 13 for antitumour activity and 1, 6 and 8 for plant protection properties are reported.
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Parker, L. „An investigation of the preparation, properties and application of some beta-carboalkoxyethyltin compounds“. Thesis, London South Bank University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372385.
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Bai, Haiping. „Solid-state NMR Studies of organotin compounds and of titania pigments“. Thesis, Durham University, 1991. http://etheses.dur.ac.uk/6286/.
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Bodzay, Steve J. „Organotin reagents toward the preparation of cyclic disulfides and related compounds“. Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72827.
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Ho, King-yan, und 何景欣. „Ecological and human health risks associated with organotin contamination in the marine environment of Hong Kong and Shenzhen, China“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208427.
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Organotin compounds (OTs), in particular tributyltin (TBT) and triphenyltin (TPT), have caused widespread adverse effects on marine organisms ever since their wide application as biocides in 1960s. For instance, TBT can induce the abnormal development of imposex in marine gastropods, and inhibit development and growth in oysters. A mandatory global ban on the use of OT-based antifouling systems, therefore, has been enacted by the International Maritime Organization to minimize their environmental impacts since September 2008. As a result, it is anticipated to see a reduction of OT contamination in the marine environment around the world. This study, therefore, primarily aims to test the hypothesis that there is a reduction of both OT contamination and its associated adverse impact to a common biomonitor, the rock shell Reishia clavigera along the coast in Hong Kong and Shenzhen, China through a series of field-based investigations.
Before the field study, a method was successfully developed to simultaneously quantify the concentrations of six common OTs (i.e., mono-BT, di-BT and TBT; mono-PT, di-PT and TPT) in molluscan tissues using gas chromatography-mass spectrometry. These six compounds coexist in marine environments. They are highly toxic to marine organisms and are able to induce imposex in gastropods like R. clavigera.
First, a territory-wide survey on tissue concentrations of the OTs and imposex status in R. clavigera collected from 28 coastal sites of Hong Kong was conducted in 2010. The results indicated that all female R. clavigera suffered from imposex, and all rock shells contained high TPT concentrations. A probabilistic ecological risk assessment revealed that 17.6% of R. clavigera across all sites were at risk due to exposure to TPT, whereas the risk associated with TBT was relatively low. The same species collected from Dapeng Bay and Daya Bay, Shenzhen also exhibited high tissue concentrations of TPT. Second, R. clavigera transplanted from relatively clean sites to polluted sites for six months showed increases in both imposex status and tissue concentration of OTs, confirming the association between OT contamination and imposex development. Third, a 25-month population dynamics study of R. clavigera showed a limited recruitment of the species in the polluted sites.
To verify if the observed OT contamination was widespread to other marine species in Hong Kong waters, a survey on the tissue concentrations of OTs in 11 local seafood species was conducted. Among them, the tongue sole Paraplagusia blochii had the highest tissue concentration of total OTs, with TPT as the most abundant residue. Potential health risk for consuming this benthic fish species was identified as both hazard quotient of TPT and hazard index exceeded unity.
The overall results demonstrate that the coastal marine environments in this region are still heavily contaminated with OTs especially TPT, and there is no obvious sign of recovery of R. clavigera populations. Hopefully, with further scientific investigations, both Hong Kong and China governments will take appropriate management actions to control the use and release of these priority pollutants with a view to safeguarding the marine ecosystem and human health in this region.HKU 3 Minute Thesis Award, 2nd Runner-up (2013)
published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy
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Harston, P. „The thermal stability encapsulation in glass, and exchange reactions, of organotin compounds“. Thesis, University of Aberdeen, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387462.
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The thermolysis of organotin compounds R3SnX (R=Ph, Bu, Cy, Neo, Bnz; X=Cl, OSnRa, SnR3, O2CR'), R2"SnO and R"Sn(O)OH (where R"=Bu, Oct) has been investigated by thermal analysis, gas chromatography and Mössbauer spectroscopy. Several decompositions of R3SnX occurred via disproportionation to the tetra- and di-organotin products. Organotin compounds were successfully encapsulated into sized metal acetate glasses, with little or no decomposition of the organotin. Both halide/acetate and oxide/acetate exchanges occurred in the melt; partial exchange was realised with sterically hindered trineophyltin chloride. Tin-tin and tin-sulphur bonds were unaffected by the acetate melt; and only tin-carbon bond cleavage found was with tribenzyltin chloride. Mössbauer spectra of the compounds encapsulated into the acetate glass generally had identical spectra to the pure compounds in those cases where no exchange occurred; in contrast when anion exchanges occurred the trapped organotin compounds had different Mössbauer spectra to those of the starting material and the exchange product. Reactions between BX3 (X=F, Br or Cl) and TiCl4 with R3SnCH2CH=CHR' (I, R=Me, Bu or Cy; R'=H or Me) were studied by NMR spectroscopy. Allyl group/bromide exchanges occur between I and BBr3 at (<50°C), at higher temperature (ca - 10°C) I (R=Me or Bu but not Cy) reacts further to give R2SnBr2. Reaction between BCl3 and I (R=Bu; R'=H) at (<50°C) proceeded to form only Bu3SnCl. No allyl group/fluorine exchange products were detected from the reaction between I and BF3.Et2O below -20OC, however at 25°C I (R=Me; R'=H) reacts readily with BF3.Et2O, the predominant soluble tin species being Me4Sn. Compounds I and TiCl4 at 30°C rapidly produce R3SnCl and (RCHCHCH2)TiCl3.
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Thongkon, Nisakorn. „Method development for the speciation analysis of chromium, organotin and arsenic compounds“. Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364913.
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FELIZZOLA, JULIANA FEITOSA. „ESPECIATION OF ORGANOTIN COMPOUNDS IN SURFACE SEDIMENTS OF TODOS OS SANTOS BAY“. PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2005. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=6723@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOA liberação de compostos butílicos de estanho, como o tributilestanho (TBT), presentes em tintas anti-incrustantes de embarcações marítimas, tem provocado efeitos nocivos sobre a reprodução e o crescimento das várias formas de vida marinha. Em resposta a estes riscos ambientais, vários países regulamentaram ou baniram o uso destes produtos anti-incrustantes. No Brasil, não existe ainda qualquer controle sobre o uso destes compostos em embarcações trafegando em território nacional. O presente trabalho visou estudar a presença de tributilestanho (TBT) e de seus produtos de degradação, dibutilestanho (DBT) e monobutilestanho (MBT), em sedimentos superficiais provenientes de 17 estações de coleta na Baía de Todos os Santos. A seleção das estações para o estudo proposto foi baseada no histórico do fluxo de navios cargueiros, presença de marinas e pólos industriais localizados próximos a cada estação. A especiação dos compostos orgânicos de estanho foi realizada por cromatografia em fase gasosa com detecção por fotometria de chama pulsante, após extração por solvente, derivação, limpeza dos extratos e eliminação de enxofre. As maiores concentrações detectadas (em ng g-1 sedimento, como Sn) para os diferentes compostos organoestânicos foram: TBT (15,9), DBT (28,8) e MBT (4). Os sedimentos superficiais analisados encontram-se levemente contaminados, segundo a classificação reportada por Waite e colaboradores (1991), mas mostram valores bem inferiores aos encontrados na Baía de Guanabara (Almeida et al., 2004), possivelmente devido a propriedades como transparência da água, que favorece a fotodegradação, e ambiente sedimentar oxidante.
The organotin compounds such as tributyltin (TBT) present in anti-fouling paints applied to ships, pleasure boats and vessels are proved to have harmful effects on the reproduction and the growth of several forms of marine life. In response to this environmental threat many countries introduced restriction to their use or even banishment. In Brazil there are no such rules on the use of these compounds. The present work aimed at the speciation of organotin compounds (tributyltin (TBT) and its of degradation products, dibutyltin (DBT) and monobutyltin (MBT)) in surface layer of sediments collected from 15 stations in the Todos os Santos Bay. The selection of stations was based on information on ship traffic, presence of marinas and industries installation. Organotin speciation was carried out by gas chromatography with pulsed flame photometric detection after solvent extraction, derivatization, clean-up and sulfur elimination. The highest organotin concentrations (ng g -1 as tin) found were: TBT (15,9), DBT (28,8) e MBT (4). Sediments in the studied locations are slightly contaminated, according to the classification reported by Waite and collaborators (1991). Values are lower than those found in Guanabara Bay (Almeida et al., 2004) possibly due to the higher water transparence that favors photo degradation, and to the oxidizing sedimentary environment.
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SK, Kamruddin. „Studies on the organotion carboxylates and related compounds : syntheses, structures and properties, including biocidal properties of organotin derivatives of carboxylate ligands containing additional donor sites (e.g. N, S.)“. Thesis, University of North Bengal, 1996. http://hdl.handle.net/123456789/770.
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Xu, Jun. „Toxic effects of triphenyltin on the freshwater alga Scenedesmus quadricauda (chlorophyceae)“. HKBU Institutional Repository, 2010. http://repository.hkbu.edu.hk/etd_ra/1223.
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Stem, Joseph Michelle R. „Computational modeling studies of the structures and properties of organotin(IV) and stannyl-thioether systems with comparisons to X-ray crystallography“. To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Lawrence, Monique A. M. „The adsorption of phenolic and organotin compounds by clays and cation exchanged clays“. Thesis, Aston University, 1996. http://publications.aston.ac.uk/9677/.
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Quaternary ammonium exchanged laponites (Quat-laponites) show selectivity in the adsorption of phenols and chlorinated phenols. Strong adsorbate-adsorbent interactions are indicated by adsorption isotherms. Adsorption of phenols and chlorinated phenols by Quat-smectites is greater than that by the Bi Quat-Smectites prepared in this study. It is thought that the quaternary ammonium exchanged smectite components of the Bi Quat-smectites interact with each other (adsorbent-adsorbent interactions) reducing the number of sites available for adsorbate-adsorbent interactions. Solidification/stabilisation studies of 2-chlorophenol show that a blend of ground granulated blast furnace slag and ordinary Portland cement attenuates 2-chlorophenol more effectively than ordinary Portland cement alone. Tetramethyl ammonium- (TMA-) and tetramethyl phosphonium- (TMP-) montmorillonites were exposed to solutions of phenol or chlorinated phenols. TMP- montmorillonite was the better adsorbent and preferentially adsorbed 4-chlorophenol over phenol. Hydration of the interlayer cations occurs to a greater extent in the TMA-montmorillonite than the TMP-montmorillonite restricting interlayer adsorption. Contrary to that observed for phenols and chlorinated phenols, the Quat-smectites were ineffective as adsorbents for triphenyltin hydroxide and bis(tributyltin) oxide at room temperature. Under microwave conditions, only bis(tributyltin) oxide was adsorbed by the quaternary ammonium exchanged smectites. Bis(tributyltin) oxide was adsorbed from ethanol on the surface of the smectite clays at room temperature and under microwave conditions. The adsorbate-adsorbent interactions were weak. Adsorption is accompanied by conversion of bis(tributyltin) oxide to a different tin(IV) species and the release of sodium cations from the montmorillonite interlayer region. Attempts to introduce conditions suitable for charge transfer interactions between synthesised quaternary ammonium compounds and 2,4,6-trichlorophenol are documented. Transition metal complex exchanged clays adsorb 2,4,6-trichlorophenol and phenol. Strong adsorbate-adsorbent interactions (Type I isotherms) occur when the adsorbate is 2,4,6-trichlorophenol and when the adsorbent is [Fe(bipy)3]2+ exchanged montmorillonite or [Co(bipy)3]3+ exchanged montmorillonite. The 2,2'-bipyridyl ligands of the adsorbents are electron rich and the 2,4,6-trichlorophenol is electron deficient. This may have enhanced adsorbate-adsorbent interactions.
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Nwata, Basil Ugwunna. „Chromatographic determination of organotin compounds by using spectrophotometric and thermospray ionization mass spectrometric detection“. Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27608.
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An assay based on HPLC-UV, HPLC-GFAAS and HPLC-MS was developed for
the chromatographic separation and characterization of organotin compounds in some marine invertebrates of British Columbia.
To enable HPLC-UV detection, butyltin complexes of high extinction coefficients were synthesized, and their chromatographic behavior is described. This approach was abandoned because of the increase in instability of the derivatives.
In the marine organisms studied, mainly bivalves, tributyltin and dibutyltin compounds were detected by HPLC-GFAAS. The presence of these compounds indicates that the maritime industry or the lumber industry is the major source of butyltin pollution in the areas sampled.
Varying amounts of tributyltin compounds in the range 1.14-4.29 μg/mL as Sn (wet weight) and dibutyltin compounds in the range 0.81-4.62 μg/g as Sn (wet weight) were found in the tissues.
The butyltin content of the shells of marine organisms was also examined. Varying amounts of tributyltin and dibutyltin compounds in the concentration range 6.60-115.60 μg/g as Sn and 5.20-49.40 μg/g as Sn respectively were detected by atomic absorption spectrophotometry.Science, Faculty of
Chemistry, Department of
Graduate
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ALMEIDA, ANA CRISTINA MARTINS. „GEOCHRONOLOGY OF ORGANOTIN COMPOUNDS AND OF SOME ENVIRONMENTALLY RELEVANT METALS CASE STUDY: GUANABARA BAY“. PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4070@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORO presente trabalho visou estudar a geocronologia da contaminação na Baía de Guanabara por compostos orgânicos de estanho e alguns metais de relevância ambiental. Foram coletados testemunhos sedimentares em cinco pontos da Baía de Guanabara em regiões não afetadas diretamente por fontes de contaminação conhecidas. Os trinta primeiros centímetros de cada testemunho foram seccionados em segmentos finos nas estações onde haviam dados de taxas de sedimentação. Para duas estações, onde as taxas de sedimentação não eram conhecidas, os testemunhos coletados foram seccionados em camadas de três centímetros e, em seguida, datados pelo método de Pb-210. As concentrações dos metais foram determinadas por ICP-MS após decomposição das amostras a quente com HNO3 e H2O2. A especiação dos compostos orgânicos de estanho foi realizada por cromatografia gasosa com detecção por fotometria de chama pulsante após extração por solvente, derivação, eliminação de enxofre e limpeza dos extratos. As maiores concentrações (em ng g-1 sedimento, como Sn) para os diferentes compostos organoestânicos encontrados foram: TBT (82), DBT (28) e MBT (126). As distribuições espacial e temporal das espécies orgânicas de estanho nos sedimentos apresentaram-se muito irregulares e há pouca evidência de degradação após a sedimentação. Foram feitas tentativas de estimar a constante de degradação do TBT e os fluxos foram calculados utilizando-se as taxas de sedimentação e as concentrações. As concentrações de organoestânicos são baixas em comparação com as reportadas para a Marina da Glória por Fernandez (2001) e confirmam a tendência à rápida deposição dos compostos orgânicos de estanho próximo às fontes dos mesmos. As concentrações dos metais-traço investigados (em ug g-1 sedimento), As (1,31-11,5), Ca (2,08x103-8,72x103), Cd (< L. D.-7,94x10-1), Cu(0,222x101-5,58x101), Fe (0,564x104-3,33x104), Hg (0,046-2,35), Mg (0,128x104-1,31x104), Mn (0,496x102-11,8x102), Ni (0,288x101-3,17x101), Pb (0,505x101-8,18x101), Sn (0,130x101122), Zn (0,162x10²-2,30x10²) quando normalizados em relação à concentração de alumínio, mostraram, em geral, um acréscimo ao longo do tempo, demonstrando que, desde a última avaliação geocronológica, realizada na década de 80 do século XX, não há redução visível no aporte de contaminantes. Não foram encontrados dados pretéritos de arsênio em sedimentos da Baía de Guanabara. Em algumas estações, os valores encontrados para este elemento são comparáveis às concentrações em estuários sob influência de atividades de mineração. Foram feitas correlações de Spearman entre as propriedades medidas, incluindo carbono total e orgânico, nitrogênio total, enxofre total, pH, potencial redox, umidade e porosidade, revelando dependências de fontes e de propriedades físico-químicas.
The present work aimed at studying the geochronology of contamination in Guanabara Bay as related to organotin compounds and a number of metals of environmental relevance. For this, sediment cores were taken from five different stations in the bay selected as to represent average conditions not immediately affected by known sources. The cores were sliced in thin segments up to 30 cm below the top layer. For two stations where sedimentation rates were not known cores were collected and sliced in 3 cm segments and thereafter dated by using Pb-210. Metal concentrations were determined by ICP-MS after digestion of freeze dried sediments in HNO3 and H2O2 under heat. Organotin speciation was carried out in a GC-PFPD instrument after solvent extraction, derivatization, sulfur elimination and clean-up. The higher organotin concentrations (ng g-1 as tin) found were: TBT (82), DBT (28) and MBT (126). Space-time distribution of organotin species in the sediments were very irregular and there is little evidence that extensive degradation occurs after sedimentation. Attempts are presented to derive an estimate for TBT degradation constant. Fluxes were calculated using the sedimentation rates and concentrations. Organotin concentrations are low in comparison to those reported for Marina da Glória by Fernandez (2001), and they confirm the tendency of organotins to settle down rapidly in the vicinities of the sources. The concentrations (ug g-1) of the investigated metals (As (1.31-11.5), Ca (2.08x103-8.72x103), Cd (
38
Uzal, Barbeito Luis Angel. „Preparation of calibrants for speciation studies of organotin and organoarsenic compounds in environmental samples“. Thesis, University of Aberdeen, 1995. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU068091.
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In the first section of this thesis, series of tetraorganotin compounds have been synthesised for their use as calibrants in speciation studies. The preparation of these organotin species involve the combination of alkylation of organotin halides with Grignard reagents and selective cleavage of carbon-tin bonds using iodine as cleavage reagent. Some of the compounds synthesised have been used to carry out a comparative study of derivation of butyltin halides by pentylation using pentylmagnesium bromide, PeMgBr, and by ethylation with sodium tetraethylborate, NaBEt4. The determination of the resulting tetraalkyltin species was made by Gas Chromatography with Flame Photometric Detection, GC-FPD. No significant differences between both procedures were found. The capability of sodium tetraethylborate as ethylating reagent was tested for other organotin compounds such are organotin oxides, carboxylates and mercaptides. It was found that, in some cases, the success of the reaction depends on the volume of the other groups attached to the tin centre. Finally it was study the selectivity of the reaction of sodium tetraethylborate with organotin halides with alkyl chains carrying other functional groups (i.e. carboxylates, phosphines) bonded to the tin atom. In the second section, it is described the synthesis of some arsenoribosides related with the organoarsenic species that so far have been isolated and identified in marine organisms and that are considered of interest for the fully establishment of the biodegradation pathways which lead to the formation of the major organoarsenic species in marine environments, the arsenobetaine.
39
Voulvoulis, Nikolaos. „Environmental analysis and assessment of biocides used in antifouling paints as alternatives to organotin compounds“. Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325576.
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Ayanda, Olushola Sunday. „Adsorption of organotin compounds on nano metal oxide/silica, activated carbon and fly ash composite materials“. Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/760.
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Thesis submitted in fulfilment of the requirements for the degree
Doctor of Technology: Chemistry
in the Faculty of Applied Sciences
at the Cape Peninsula University of Technology
2013In this present study, the physicochemical properties, nature and morphology of prepared composite materials involving activated carbon, fly ash, nFe3O4, nSiO2 and nZnO in the 1:1 ratio for two components composite materials and 1:1:1 for three components composite materials were investigated. The nature, morphology and elemental characterizations of these materials were carried out by means of modern analytical methods such as scanning electron and transmission electron microscopy (SEM and TEM), x-ray diffraction (XRD), x-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared spectroscopy (FTIR). Other physicochemical characterizations undertaken were CNH analysis, ash content, pH, point of zero charge and surface area and porosity determination by Brunauer, Emmett and Teller (BET). The precursors and composite materials were then applied to the sorption (remediation) of tributyltin (TBT) and triphenyltin (TPT) from artificial seawater and wastewater and the adsorption efficiencies for the precursors and the composites compared. The adsorption of TBT and TPT onto these materials as a function of adsorbent amount, contact time, pH, stirring speed, initial adsorbate concentration and temperature was investigated. Maximum organotin adsorption was recorded within the pH range of normal saline water (pH 8). Approximately 99.95 %, 95.75 %, 96.78 %, 99.88 %, 96.96 %, 99.98 %, 99.99 %, 99.99 % and 99.99 % TBT were removed from 25 mL of 100 mg/L TBT-contaminated artificial seawater using 0.5 g adsorbents at a contact time of 60 min, pH 8, stirring speed 200 rpm and temperature of 80 oC by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/activated carbon, nSiO2/activated carbon and nZnO/activated carbon composite, respectively and the adsorption of TBT onto these adsorbents was endothermic. Approx. 99.99 %, 96.54 %, 95.50 %, 96.92 %, 97.14 %, 99.99 %, 98.44 %, 98.98 % and 99.66 % TPT were also removed from 25 mL of 100 mg/L TPT-contaminated artificial seawater using 0.5 g adsorbents at a contact time of 60 min, pH 8, stirring speed 200 rpm and a temperature of 20 oC by the activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composite, respectively. The adsorption of TPT onto activated carbon and fly ash/activated carbon composite from TPT – contaminated artificial seawater was endothermic while TPT adsorption onto fly ash, nFe3O4, nSiO2, nZnO, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composites from TPT – contaminated artificial seawater was exothermic. The adsorption of TBT and TPT onto nFe3O4/fly ash/activated carbon and nSiO2/fly ash/activated carbon composites from TBT – and TPT – contaminated water, respectively were endothermic and approx. 99.98 % and 99.99 % of TBT and TPT, respectively were removed from the initial concentration of 100 mg/L OTC by the composites at a temperature of 80 oC, 60 min contact time, pH 8 and a stirring speed of 200 rpm. The adsorption kinetics of all the precursors and composite materials fitted well with the pseudo second-order kinetic model while the adsorption isotherm data could be well described by the Freundlich isotherm model except TBT adsorption onto nZnO/activated carbon and nFe3O4/activated carbon composite from TBT contaminated artificial seawater, TPT adsorption onto activated carbon and fly ash/activated carbon from TPT contaminated artificial seawater, and TPT sorption onto nSiO2/fly ash/activated carbon composite from TPT – contaminated water which could be described by both the Freundlich and Dubinin-Radushkevich (D-R) isotherm models. Optimal conditions for the adsorption of TBT and TPT from artificial seawater were further applied to TBT and TPT removal from TBT – and TPT – contaminated natural seawater obtained from Cape Town harbour and the results obtained show that 99.71 %, 79.23 %, 80.11 %, 82.86 %, 80.42 %, 99.75 %, 99.88 %, 99.83 % and 99.88 % TBT were removed from TBT – contaminated natural seawater by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/activated carbon, nSiO2/activated carbon and nZnO/activated carbon composite, respectively while 99.90 %, 96.44 %, 95.37 %, 96.75 %, 97.03 %, 99.92 %, 98.42 %, 98.92 % and 99.58 % TPT were removed from TPT – contaminated natural seawater by activated carbon, fly ash, nFe3O4, nSiO2, nZnO, fly ash/activated carbon, nFe3O4/fly ash, nSiO2/fly ash and nZnO/fly ash composite, respectively. Experimental results therefore show that the composite materials present higher organotin adsorption efficiency than the precursors due to the nature and improved properties of the composite materials and can therefore be utilized for the remediation of organotin contamination from industrial and/or shipyards process wastewater to > 99 % reduction before discharge into the environment.
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Okoro, Hussein Kehinde. „Environmental assessment of heavy metals and organotin compounds in Cape Town harbour, monitoring geochemistry and toxicity“. Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/763.
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Analytical methods for speciation of targeted organotin compounds (TBT and TPT)
in water samples using SPE cartridge and liquid-liquid extraction has been carried out. Also,
sediment analysis using methanol - acid digestion and acid- sonication extraction methods
were also developed. Different parameters affecting extraction and peak resolution were
optimised. Also, three derivatisation procedures were optimised. The accuracy of the
extraction procedure was also verified on certified reference material (BCR - 462) certified for
TBT (54 ± 15 µg/kg) and DBT (68 ± 12 µg/kg). Freeze - dried mussel tissue (ERM - CE 477)
certified for TBT (2.20 ± 0.19 mg/kg), DBT (1.54 ± 0.12 mg/kg) and MBT (1.50 ± 0.28 mg/kg).
Good recoveries were obtained with methanol - acid digestion. The results were validated by
analysing the real water and sediment samples collected from Cape Town harbour and the
compounds were detected in both water and sediment samples, respectively.
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Gabriele, Giuseppina [Verfasser]. „Spacer-bridged ditin compounds as bicentric Lewis acids and synthons for novel organotin oxo clusters / Giuseppina Gabriele“. Dortmund : Universitätsbibliothek Technische Universität Dortmund, 2004. http://d-nb.info/1011531976/34.
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Cole, Russell Francis. „Determination of organotin compounds in coastal sediment pore-water by diffusive gradients in thin-films (DGT) technique“. Thesis, University of Portsmouth, 2016. https://researchportal.port.ac.uk/portal/en/theses/determination-of-organotin-compounds-in-coastal-sediment-porewater-by-diffusive-gradients-in-thinfilms-dgt-technique(f452f268-d8c7-4ca9-acb3-ffd6fb733f8e).html.
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Organotin compounds still present a high risk to biota in the aquatic environment. Measuring the behaviour of the freely dissolved fractions of these compounds in sediment compartments is challenging, with costly and sensitive analytical techniques required for their measurement. Diffusive gradients in thin-films (DGT) allow for the uptake and pre-concentration of analytes in a binding gel and is used to measure dissolved metals and some organic compounds. The utility of novel silica-bound sorbents (C8, C18, mixed phases) as DGT binding gels for the sequestration of organotins in the marine environment was the primary focus of work in this project. The C8 sorbent showed the optimum performance in the uptake and recovery of organotins across pH, ionic strength and in filtered sea water. It was used subsequently as the binding layer in DGT sediment devices (160 mm × 34 mm) overlaid with a mixed-cellulose ester membrane (0.45 μm) as the single diffusion layer. These were used to investigate pore water mobilisation and concentrations of organotins in coastal sediment cores collected from a contaminated site. Organotins demonstrated a non-sustained uptake scenario, with DGT flux and freely dissolved concentrations in pore water measured to decline at 1 cm depth intervals over deployments of 2-28 days. Using time series, concentrations in pore water at t = 0 were calculated providing empirical pore water depletion curves for sediment cores. Using standard laboratory instrumentation (i.e. gas chromatography-mass spectrometry) low limits of detection were achieved (TBT = 0.4 ng L-1 after 2 weeks of sampling).
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Regoli, Lidia. „Organotins in zebra mussels, Dreissena polymorpha, and sediments from the Saint-Lawrence River“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0018/MQ55088.pdf.
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Yi, Xianliang Andy, und 易先亮. „A comprehensive study on the ecological toxicity and risk of triphenyltin to aquatic organisms“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/202351.
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Alashkar, Nour [Verfasser], Klaus [Akademischer Betreuer] Jurkschat und Sonja [Gutachter] Herres-Pawlis. „Aminopropyl-substituted organotin compounds for sensing, detection and removal of fluoride anions / Nour Alashkar ; Gutachter: Sonja Herres-Pawlis ; Betreuer: Klaus Jurkschat“. Dortmund : Universitätsbibliothek Dortmund, 2016. http://d-nb.info/1124231188/34.
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Baba, Haj Samer [Verfasser], Klaus [Akademischer Betreuer] Jurkschat und Stefanie [Gutachter] Dehnen. „Functionalized organotin compounds as synthons for tin-containing heterocycles and periphery functionalized organotinoxo clusters / Samer Baba Haj. Betreuer: Klaus Jurkschat. Gutachter: Stefanie Dehnen“. Dortmund : Universitätsbibliothek Dortmund, 2015. http://d-nb.info/1102268992/34.
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Ayari, Jihed [Verfasser], Klaus [Akademischer Betreuer] Jurkschat und Uwe [Gutachter] Zachwieja. „Tripod-shaped organotin compounds: complexation studies towards Lewis bases and chalcogenido clusters of unprecedented nuclearity / Jihed Ayari ; Gutachter: Uwe Zachwieja ; Betreuer: Klaus Jurkschat“. Dortmund : Universitätsbibliothek Dortmund, 2020. http://d-nb.info/1225557089/34.
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Chaudhary, Praveen, und University of Lethbridge Faculty of Arts and Science. „Lewis-acid and fluoride-ion donor properties of SF₄ and solid-state NMR spectroscopy of Me₃SnF“. Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Chemistry and Biochemistry, c2011, 2011. http://hdl.handle.net/10133/2621.
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Trimethyltin fluoride (Me3SnF) is a useful fluorinating agent in organometallic
chemistry. Its solid-state structure has been investigated by X-ray crystallography
showing a polymeric fluorine-bridged structure. Disorder, however, has precluded the
accurate refinement of all structural parameters. In order to obtain accurate structural
information, trimethyltin fluoride was investigated using high-resolution 13C, 19F, and
119Sn solid-state NMR spectroscopy using a four-channel HFXY capability. The
119Sn{1H} solid-state NMR spectrum agrees with pentacoordination about Sn in this
compound. The high-resolution 119Sn{19F, 1H}, 13C{1H,19F} and 19F{1H} NMR spectra offer unambiguous determination of 1J(119Sn-19F) and 1J(119Sn-13C) coupling constants. Furthermore, the analysis of the 119Sn{19F, 1H}, 119Sn{1H}, and 19F{1H} MAS spectra as a function of spinning speed allowed for the determination of the 119Sn CSA and J anisotropy, as well as the 119Sn-19F dipolar couplings. These were determined via SIMPSON simulations of the 13C, 19F, and 119Sn NMR spectra. Finally the 119Sn{19F, 1H} revealed fine structure as the result of 119Sn-117Sn two bond J-coupling, seen here for the first time. Sulfur tetrafluoride can act as a Lewis acid. Claims had been presented for the formation of an adduct between SF4 and pyridine, but no conclusive characterization had been performed. In the present study, adducts of SF4 with pyridine, lutidine, 4-picoline and triethylamine were prepared and characterized by low-temperature Raman spectroscopy. Sulfur tetrafluoride also acts as a fluoride-ion donor towards strong Lewis acids, such as AsF5 and SbF5, forming SF3
+ salts. Variable-temperature (VT) solid-state 19F NMR spectroscopy showed that SF3
+SbF6 – exists in three phases with phase transitions at ca. –45 and –85°C, while SF3
+AsF6 – exists only as one phase between +20 and –150 °C. The phases of SF3
+AsF6 – were also characterized by VT Raman spectroscopy.xvi, 170 leaves : ill. (some col.) ; 29 cm
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Lima, Barbosa Ana Soraya. „Organometallic compounds of tin and ruthenium : applications in medicinal chemistry“. Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF029.
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Nous avons synthétisé des composés d'étain avec des acides undécylénique, ricinoléique et caprylique. Ils ont une activité importante contre certaines souches de microrganismes, puisque ils agissent pour certains d’entre eux à des concentrations nanomolaires. Staphylococcus aureus semble être 4000 fois plus sensible à leur toxicité que les cellules de mammifères. Nous avons obtenu des composés du ruthénium qui présentent cytotoxicité contre des cellules cancéreuses suivant un mécanisme d'action différent de ceux observés pour le Cisplatine ou d'autres composés de Ru, grâce à leur grande stabilité dans les réactions de substitution. Enfin, pendant la vectorisation des composés dérivés du Ru avec une Affitine nous avons pu acquérir des connaissances importantes sur un éventuel mécanisme d'action de ce type de molécules dont le potentiel redox très abaissé par rapport aux composés correspondants pourrait être responsable de la polymérisation de protéines cibles par transfert d’électronRelated to antimicrobial research, we synthesized tin compounds derived from undecylenic, ricinoleic and caprylic acids and we found that they show very high activity against some strains of bacteria and yeast, even in nM range, being up to four thousand times more potent against Staphylococcus aureus than against mammalian cells. For ruthenium compounds, in turn, we have confirmed that the mode of action of some compounds that were synthesized recently is undoubtedly different from Cisplatin or other ruthenium compounds, because of their high stability toward substitution reactions. Finally, during the vectorization of compounds derived from Ru with Affitin we have gained important knowledge about a possible mechanism of action of this type of molecule: it could indeed be possible that these compounds which have a very reduced redox potential compared to corresponding compounds can cause polymerization of proteins by electron transfer