Synthesis,structural and larvicidal studies of a series of triorganotin chrysanthemumates

A series of triorganotin chrysanthemumates (2,2‐dimethyl‐3‐(2‐methyl‐1‐propenyl)cyclopropanecarboxylates) (R₃SnO₂CC₉H₁₅) where R = methyl, ethyl, n‐butyl and phenyl was synthesized. The solid state structures were deduced using infrared (IR) and Mössbauer spectroscopies. The spectroscopic results indicated that all the compounds were found to be five‐coordinated in the solid state. Based on the NMR results, all the compounds are tetrahedral in solution. Larvicidal activities of the compounds were evaluated against the second instar stage of Aedes aegypti, Anopheles stephensi and Culex pipiens quinquefasciatus mosquitoes. The toxicity results indicated that these compounds of triorganotins were effective larvicides against all three species of larvae. Copyright © 2011 John Wiley & Sons, Ltd.     

Tolerance of Aedes aegypti larvae to triorganotins

The effects of triorganotins on the 4th instar stage of Aedes aegypti larvae were evaluated. The most effective of the 15 triorganotins used in the study was tributyltin chloride with an LC₅₀ value of 0.57 ± 0.07 mg dm⁻³. The low LC₅₀ values obtained indicated that this class of compounds is an effective larvicide against the larvae of this species of mosquito. The toxicity of the compounds was found to be primarily dependent on the R group attached to the tin atom. The order of activity for the triorganotins tested was Bu > Ph > Cy > Me. However, a limited order, based on two series of the compounds tested, was also observed for the anionic X group on the tin atom. Copyright ­© 2000 John Wiley & Sons, Ltd.     

Use of Mössbauer spectroscopy to determine the effect of salinity on the speciation of triorganotins in Anacostia River sediments

The speciation of several tributyltin and triphenyltin compounds under varying salinity conditions (0, 20, 40 and 60%) was studied by Mössbauer spectroscopy in both anaerobic and aerobic Anacostia River sediments. The Mössbauer spectral parameters of the spiked sediments indicated that changes in the salinity did not affect the speciation of the tin compounds in either aerobic or anaerobic sediments.     

Toxicity of triorganotin compounds to the brine shrimp,Artemia salina

The 14 triorganotin compounds that were screened against the brine shrimp, Artemia salina, were least effective against the first nauplii stage (24 h). This was attributed to the presence of a yolk membrane which reduced the contact between the triorganotin compounds and the organism. The data indicated that the species responsible for the toxicity is primarily the hydrated triorganotin cation. However, the anion X group may also play a minor role in the toxicity of these compounds. The observed order of activity for the triorganotins does not parallel their hydrophobicities, indicating that other factors must be involved in the toxicity mechanism. Copyright © 2000 John Wiley & Sons, Ltd.