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Abstract This study concerns contents of several organotin compounds, monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPhT), diphenyltin (DPhT) and triphenyltin (TPhT), in seafood. Seafood samples were collected from markets and coastal zone in Taiwan, and contents of organotins were analyzed by Grignard reagent derivation coupled with GC/FPD. Besides, the tolerable daily intake (TDI) of (TBT+DBT), mean body weight of Taiwan citizen and the consumption of seafood were used to derive the tolerable average residue level (TARL) of the compounds. The risk assessment was implemented by comparing the content to TARL. The contents of TBT, DBT, MBT, TPhT, DPhT and MPhT in seafood ranged N. D~48.36 ng Sn/g wet wt., N. D~36.68 ng Sn/g wet wt., N. D~79.19 ng Sn/g wet wt., N. D~225.53 ng Sn/g wet wt., N. D~128.16 ng Sn/g wet wt., N. D ~ 95.44 ng Sn/g wet wt., respectively. Reference survey showed that mean body weight of Taiwan citizen is 54.42 Kg, and seafood consumption rate is 127.59 g/day/person. A TARL of 44.27 ng Sn/g wet wt. is derived accordingly. Of all the 71 samples, only 4 contain more (TBT+DBT) than the TARL. On the other hand, (TBT+DBT) contents weighed by consumed ratio averaged 3.87 ng Sn/g wet wt., which is far under the TARL. Different visions lead to the same conclusion that (TBT+DBT) content of seafood in Taiwan is far away from dangerous level. This study also concluded that cooking process doesn¡¦t affect the contents of organotin compounds of seafood, and the Grignard reagents contribute to the TBT blank signal. Furthermore, the independence between organotins and factors such as classifications, sampling area or habitat was discussed.

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Thesis (M.S.)--Florida State University, 2006. / Advisor: Marie E. Krafft, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed June 13, 2006). Document formatted into pages; contains xix, 119 pages. Includes bibliographical references.

In part I of this thesis, orgimotin compounds were investigated, using high resolution proton and tin 119 nuclear magnetic resonance technique. The tin 119 chemical shift of about forty organotin compounds were measured by absorption mode for the first time. The tin chemical shift and tin 119-proton coupling constant in some methyltinhalides wore found, to be solvent and concentration dependent in electron donor solvents. This dependence was attributed to the formation of higher than four coordinated complexes with solvent molecules. Equilibrium constants of the complex formation, the tin chemical shifts, and the tin-proton coupling constants of the complexes, wore obtained in a few solvents. The second-order paramagnetic chemical shifts of methyltinhaiides, methyltin cations, and five coordinated compounds were calculated and compared with the observed tin chemical shifts. Good qualitative agreements between calculated values and observed values confirmed that the second-order paramagnetic term in tin chemical shifts is dominant in the chemical shift changes in those compounds. In part II, X-ray irradiated single crystals of malonamide and cyanoacetamide were studied by electron spin resonance technique. In both cases at least two types of radicals were found. One was the usual π -electron type radical the proton coupling tensor of which had been studied, quite extensively in the past. In this study, besides the proton coupling and in the case of cyanoaecetamide, the coupling tensor for the cyano-nitrogen was also measured and discussed. The second radical found both in X-ray irradiated malonamide and cyanoacetamide was a Ϭ-electron type radical which was produced by the loss of one of the amide protons (-COṄH). The proton hyperfine coupling constant was found to be almost isotropic and very large, more than 80 gauss in both compounds. The nitrogen coupling tensor for the amide- nitrogen was found to be axially symmetric with the unique principal value equal to 36.6 gauss in the one (malonamide) and 25.4 gauss in the other (cyanoacetamide). The principal value in perpendicular direction was found to be very small but could not be determined conclusively. A semi-empirical molecular orbital calculation was performed on the fragment of Ϭ-electron radical together with perturbation through configuration interaction; the large isotropic proton coupling constants were explained theoretically. / Science, Faculty of / Chemistry, Department of / Graduate

This research is part of a long-term project aimed at elucidating important structural features, of both ligands and metals, that are needed to produce effective anti-cancer agents. The specific goal is the synthesis of organotin polymers containing amino acids, in this case the diamino acid diglycine. The desired materials were synthesized with percent yields ranging from 32-99%. The products were synthesized employing the interfacial polymerization technique. The polymers were then characterized utilizing the following physical characterization techniques: light scattering photometry (LS), Infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), and matrix assisted laser desorption mass spectroscopy (MALDI). Physical characterization showed evidence of formation of desired adducts in addition to data that was consistent with the formation of materials containing multiple repeat units. The materials were then analyzed for biological activity. The synthesized materials displayed the ability to inhibit tested cancer cell lines. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

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.

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.

Kaohsiung harbor is the biggest one in Taiwan. Many previous researches revealed that the pollution of organotin was usually serious in harbors. TBT contained in the antifouling paint of vessels would release into the seawater and contaminate the harbor area. In this study, shrimps (Acetes intermedius) and water samples were collected from Xinbin wharf and the second port entrance in Kaohsiung harbor. After pretreatment, ethylated with sodium tetraethylborate and extracted by hexanes, contents of organotin compounds were analyzed by GC-FPD. The results showed that TBT and DBT were the predominant organotin species in Kaohsiung harbor. In seawater, the concentration of DBT ( 98-257 ng/L ) was higher than TBT ( 17-133 ng/L). In shrimps, the concentration of TBT ( 228-480 ng/g ) was higher than DBT ( 98-257 ng/g). The concentration of TBT in shrimps decreased with the increased wet weight. There was no significant variation for the organotin concentrations in the shrimp samples collected from the second port entrance during the period from September 2002 to May 2003. The bioconcentration factor (BCF) of TBT ranged between 6700-17900. The organotin concentrations in shrimps collected from Xinbin wharf also showed no significant variation from August 2002 to May 2003. The BCF values of TBT were between 2200-8300. The ability of shrimps to concentrate organotin compounds was between that of fishes and neogastropods. There were significant differences for the organotin concentrations in shrimps sampled from different sampling area. The shrimps sampled from Kaohsiung harbor were significantly higher in organotin concentration than Tungkang. According to the risk assessment, shrimps from Tungkang were much lower than the tolerable daily intake, however, the shrimps from Kaohsiung harbor were well beyond the dangerous level . In order to understand the toxicity of organotin compounds to the shrimps, experiments on acute toxicity test were conducted. The 72-h LC50 of TBT was 47£gg/L. After toxicity test, live shrimps which were exposed to organotin for 72 hours were assayed. The concentration of TBT in shrimps increased with the exposure concentrations. DBT which was the degradation product of TBT also showed the same trend. The 72-h LC50 of DBT was 225£gg/L. After toxicity test period, the concentration of DBT and its metabolite MBT in shrimps also increased with the increased exposure concentrations. The accumulation rate of the shrimps at 30£gg/L TBT was 17ng/g-h and the elimination rate was 8.8 ng/g-h. The accumulation rate of the shrimps at 100£gg/L DBT was 12 ng/g-h and the elimination rate was 4.2 ng/g-h.