Synthesis, Characterization and antifungal activity of tin(IV) complexes with dithiocarbimates and dimethyltin

Este trabalho descreve a síntese de dez compostos inéditos de estanho derivados de sulfonilditiocarbimatos, sendo cinco complexos aniônicos e cinco complexos neutros. Os complexos aniônicos de estanho(IV) de fórmula geral (Ph4P)2[Sn(CH3)2(RSO2N=CS2)2] (Ph4P = tetrafenilfosfônio, R = fenil, 4-fluorofenil, 4-clorofenil, 2-metilfenil, 4-metilfenil) foram obtidos pela reação de ditiocarbimatos de potássio com diclorodimetilestanho(IV) e cloreto de tetrafenilfosfônio em água na proporção molar de 2:1:2. Os complexos neutros de fórmula geral [Sn(CH3)2(RSO2N=CS2)] (R = fenil, 4-fluorofenil, 4-clorofenil, 2-metilfenil, 4-metilfenil) foram obtidos pela reação dos ditiocarbimatos de potássio com diclorodimetilestanho(IV) em água na proporção molar de 1:1. As análises elementares e os dados de espectroscopias no infravermelho, de ressonância magnética nuclear de 13C, 1H e 119Sn e de Mössbauer 119Sn foram consistentes com as fórmulas propostas para os complexos. Estudos de difração de raios-X dos compostos (Ph4P)2[Sn(CH3)2(4-6H4SO2N=CS2)2] (3b) e (Ph4P)2[Sn(CH3)2(4-ClC6H4SO2N=CS2)2] (3c) mostraram uma geometria octaédrica distorcida ao redor do átomo de estanho. Os ânions ditiocarbimato estão coordenados ao metal por átomos de enxofre e nitrogênio. Não existe na literatura nenhum relato sobre esse tipo de coordenação, seja com ditiocarbimatos ou ditiocarbamatos. A atividade antifúngica dos complexos de estanho foi testada in vitro contra Fusarium solani, agente causal da murcha e da podridão radicular de um grande número de espécies de plantas, incluindo algodão, ervilha, plantas ornamentais e frutíferas. Todos os complexos foram ativos, porém menos ativos que o fungicida comercial bis(dietilditiocarbamato) de zinco(II).This work involved the synthesis of ten new tin compounds derived from sulfonildithiocarbimates, being five anionic complexes and five neutral complexes. The anionic complexes (Ph4P)2[Sn(CH3)2(RSO2N=CS2)2] (Ph4P = tetraphenylphosphonium, R = phenyl, 4-fluorophenyl, 4-chlorophenyl, 2- methylphenyl, 4- methylphenyl) were obtained by the reaction of the dithiocarbimates with dichlorodimethyltin(IV) and tetraphenylphosphonium chloride in water in 2:1:2 molar ratio. The neutral complexes [Sn(CH3)2(RSO2N=CS2)] (R = phenyl, 4-fluorophenyl, 4-chlorophenyl, 2-methylphenyl, 4- methylphenyl) were obtained by the reaction of the dithiocarbimates with dichlorodimethyltin(IV) in water in 1:1 molar ratio. The elemental analyses (CHN), vibrational spectra, 1H, 13C and 119Sn Nuclear Magnetic Ressonance spectra and Mössbauer 119Sn data were consistent with the proposed formulae. X-ray diffraction experiments for the compounds (Ph4P)2[Sn(CH3)2(4-FC6H4SO2N=CS2)2] and (Ph4P)2[Sn(CH3)2(4- ClC6H4SO2N=CS2)2] showed that two dithiocarbimate anions and two methyl groups are coordinated to the tin atom forming a distorted octahedral geometry. The ditiocarbimate anions are coordinated to the metal by sulfur and nitrogen atoms. The antifungal activity of the complexes were tested in vitro against Fusarium solani, the causal agent of wilt and root rot in a number of crops including cotton, peas, ornamentals, fruits and cucurbits. All complexes were active, but less active than the commercial fungicide bis(diethyldithiocarbamato)zinc(II)

Hydrotalcite-iron oxide and hydrotalcite-TiO2-iron oxide magnetics intercalated with anionic surfactants: adsorption studies and photodegradation of methylene blue cationic dye

Neste trabalho, a hidrotalcita foi intercalada por surfactantes aniônicos, dodecilsulfato (DS) e dodecilbenzenosulfonato (DSB), e combinado com as propriedades magnéticas do óxido de ferro produzindo os adsorventes magnéticos, inéditos, HT-DS/Fe e HT-DSB/Fe. Esses foram utilizados na remoção do corante catiônico azul de metileno (AM), composto modelo, de solução aquosa e em seguida removido do meio por um simples processo magnético. A remoção do AM de soluções aquosas foi avaliada através de experimentos de adsorção pelo método da batelada. As capacidades de adsorção máximas, obtidas a partir dos modelos de Langmuir-Freundlich, pelos organocompósitos HT-DS/Fe e HT-DSB/Fe foram de 110,05 e 94,69 mg/g, respectivamente, para adsorção do AM. As capacidades de adsorção máximas mantiveram-se elevadas, mesmo após o terceiro ciclo de reutilização (83,47 e 62,54 mg/g para HT-DS/Fe HT-DSB/Fe). Estes resultados sugerem que ambos os materiais adsorventes, HT-DS/Fe HT-DSB/Fe, são eficientes para remover concentrações relativamente elevadas de corantes catiônicos a partir de soluções aquosas. Fotocatalisadores magnéticos inéditos, HT/TiO 2 /Fe e HT- DS/TiO 2 /Fe também foram sintetizados com sucesso nesse trabalho e utilizados na fotodegradação do corante AM. O desempenho fotocatalítico foi analisado sob irradiação UV-Visível (filtro de corte >300 nm). Várias amostras de catalisadores foram preparadas com diferentes teores de titânio e ferro. O catalisador mais eficiente foi obtido com a relação molar óxido de ferro:TiO 2 de 2:3. Esse mostrou elevada atividade fotocatalítica com remoção de 96 % de cor e 61% do Carbono Orgânico Total (TOC) do AM, em um tempo de 120 min. A reutilização do catalisador mostrou ser viável e esse apresentou ser estável por pelo menos 4 ciclos fotocatalíticos consecutivos.In this work, hydrotalcite-iron oxide magnetic was intercalated with dodecylsulfate (DS) and dodecylbenzenesulfonate (DSB) anionic surfactants and properties combined with the magnetic properties of iron oxide to produce a magnetic adsorbent, unpublished, HT-DS/Fe e HT-DSB/Fe. These were used for the removal of methylene blue cationic dye (AM), a model compound, in aqueous solution and then removed from the magnetic medium by a simple process. The removal of AM aqueous solutions was evaluated through experiments by the batch adsorption method. The maximum adsorption capacity obtained from the Langmuir model, the HT-DS/Fe e HT-DSB/Fe organocompósitos were 94.69 and 110.05 mg/g, respectively, for adsorption of AM. The adsorption capacity remained high even after the third cycle of reuse (83.47 and 62.54 mg/g for HT-DS/Fe and HT-DSB/Fe). These results suggest that both adsorbent materials, HT-DS/Fe and HT-DSB/Fe, are efficient for removing relatively high concentrations of cationic dyes from aqueous solutions. Magnetic novel photocatalysts, HT/TiO 2 /Fe and HT-DS/TiO 2 /Fe were also successfully synthesized and used in this photodegradation of the dye AM. The photocatalytic performance was analyzed under UV-Visible irradiation (cutoff filter >300 nm). Several samples of catalysts were prepared with different amounts of titanium and iron. The most efficient catalyst was obtained with the molar ratio of iron oxide: TiO 2 of 2:3. This showed high photocatalytic activity with the removal of 96 % of color and 61 % of Total Organic Carbon (TOC) of MB in a time of 120 min. The reuse of the catalyst, HT-DS/TiO 2 /Fe was found to be viable and this showed to be stable for at least 4 consecutive photocatalytic cycles.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Syntheses, crystal structure and spectroscopic characterization of new platinum(II) dithiocarbimato complexes.

The reaction of 4-iodobenzenesulfonamide or 4-fluorobenzenesulfonamide with CS2 and KOH in dimethylformamide yielded the potassium N-R-sulfonyldithiocarbimates, K2(RSO2N@CS2) [R = 4-IC6H4 (1) and 4-FC6H4 (2)]. These salts reacted with K2[PtCl4] in water/methanol to yield complex anions bis(N-R-sulfonyldithiocarbimato) platinate(II), which were isolated as their tetrabutylammonium salts, (Bu4N)2[Pt(RSO2N@CS2)2] [R = 4-IC6H4 (3) and 4-FC6H4 (4)]. The structures of 2–4 were determined by X-ray crystallography. The Pt2+ in both complexes 3 and 4 lies at the inversion centre and the PtS4 moiety has a distorted square-planar configuration. The compounds were also characterized by IR, 1H NMR and 13C NMR spectroscopies, and elemental analyses. The molar conductance data are consistent with the fact that 3 and 4 are dianionic complexes

Enhanced photocatalytic activity of TiO2-impregnated with MgZnAl mixed oxides obtained from layered double hydroxides for phenol degradation

A series of TiO2/MgZnAl photocatalysts were successfully synthesized from ternary (Mg, Zn and Al) layered double hydroxides impregnated with TiO2 nanoparticles by the co-precipitation method at variable pH with different Zn2+/Mg2+ molar ratios. The composite photocatalysts were calcined at 500 °C resulting in the incorporation of oxide zinc, in the calcined MgZnAl LDH structure. Synergistic effect between ZnO and TiO2 lead to significant enhancement of TiO2/MgZnAl photocatalytic activity. Composite photocatalysts were characterized by ICP-MS, N2 adsorption-desorption, XRD, SEM, EDS, IR and UV–vis DRS. Phenol in aqueous solution (50 mg/L) was used as a model compound for evaluation of UV–vis (filter cut-off for λ > 300 nm) photocatalytic activity. The most efficient photocatalyst composite was obtained at a 5% Zn2+/Mg2+ molar ratio, in the catalyst identified as TiO2/MgZnAl-5. This composite catalyst had high photocatalytic activity, completely destroying phenol and removing 80% of total organic carbon in solution after 360 min. The TiO2/MgZnAl-5 catalyst remained relatively stable, presenting a 15% decrease in phenol degradation efficiency after five consecutive photocatalytic cycles

Exposure to the insecticide endosulfan induces liver morphology alterations and oxidative stress in fruit-eating bats (Artibeus lituratus)

Exposure to pesticides may increase the generation of reactive oxygen species (ROS), leading to oxidation of cell membrane lipids and proteins. Although fruit bats are potentially exposed to pesticides during their entire lifespan, the impacts of this exposure are still poorly investigated. We examined the effects of low, commercially recommended concentrations (0, 1.05 and 2.1 g/l) of an organochlorine insecticide endosulfan (EDS) formulation on oxidative responses in the liver and kidneys of Neotropical fruit bats (Artibeus lituratus), as well as possible liver morphological alterations following a 35-day oral exposure. Superoxide dismutase activity was significantly decreased upon exposure to 1.05 g/l of EDS in the liver and kidneys, catalase was decreased in the liver of 2.1 g/l EDS-exposed bats, while glutathione S-transferase was increased in the liver of 2.1 g/l EDS-exposed bats. Protein carbonyls increased following the exposure to the highest EDS dose tested. Endosulfan-induced morphological alterations in the liver included cell degeneration and cell death, with apparent cytoplasm lipid accumulation (steatosis) and pyknotic nuclei, karyolysis and deposit of collagen fibres. Our findings suggest that exposure to low concentrations of EDS induced a certain extent of oxidative damage in fruit bats, which may have led to liver morphological alterations

Syntheses, crystal structure, spectroscopic characterization and antifungal activity of new N-R-sulfonyldithiocarbimate metal complexes.

Five new compounds with the general formula of (Bu4N)2[M(RSO2N@CS2)2], where Bu4N = tetrabutylammonium cation, (M = Ni, R = 4-FC6H4) (1), (M = Zn, R = 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-IC6H4), (2), (3), (4) and (5), respectively, were obtained by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2N@CS2K2) with nickel(II) chloride hexahydrate or zinc(II) acetate dihydrate in metanol:water 1:1. The elemental analyses and the IR data are consistent with the formation of the expected bis(dithiocarbimato) metal(II) complexes. The 1H and 13C NMR spectra showed the signals for the tetrabutylammonium cation and the dithiocarbimate moieties. The compounds 1, 2 and 5 were also characterized by X-ray diffraction techniques. The nickel(II) is coordinated by two N-4-fluorophenylsulphonyldithiocarbimato(2-) ligands forming a planar coordination. The zinc(II) exhibits distorted tetrahedral configuration in compounds 2 and 5 due to the chelation effect of two sulfur atoms of the N-R-sulfonyldithiocarbimate ligands. The antifungal activities of the compounds were tested in vitro against Colletotrichum gloeosporioides, an important fungus that causes the plant disease known as anthracnose in fruit trees. All the complexes were active