Antimony

About: Antimony is a research topic. Over the lifetime, 11450 publications have been published within this topic receiving 155660 citations. The topic is also known as: Sb & element 51.

Photochemistry and Photophysics of Antimony(III) Hyper Porphyrins: Activation of Dioxygen Induced by a Reactive sp Excited State

Abstract: Observations of the photoredox reactivity of antimony(III) porphyrin complexes are reported. Upon irradiation with visible light under ambient conditions, a photooxidation to the corresponding dihydroxoantimony(V) porphyrins occurs. At the same time a two-electron or four-electron reduction of molecular oxygen takes place, depending on the experimental conditions. In the absence of suitable electron acceptors, a photoinduced disproportionation reaction occurs. The photolysis of antimony(III) porphyrins shows a pronounced wavelength dependence. The reactive excited state is concluded to be of the metal-centered sp type. An extended model for the electronic structure of p-type hyper metalloporphyrins is suggested.

Removal of Sb(III) and Sb(V) from Aqueous Solutions Using nZVI

Abstract: Nanoscale zero-valent iron (nZVI) was synthesized and used for the removal of Sb(III) and Sb(V) from aqueous solutions. Results showed that more than 90 % of antimony would be removed in 15 min and that all of antimony could be removed with appropriate nZVI dosage in 90 min. The influence of pH value and possible impurities was investigated. The pH of 4 was found as the optimum pH. Discussion and speculation about the mechanism were presented according to X-ray photoelectron spectroscopy and transmission electron microscopy data. A sheet-like structure was observed after a 90-min reaction, and antimony was detected on the surface by energy-dispersive X-ray spectroscopy. Both Sb(III) and Sb(V) partially reduced in the process. The presence of humic acid transformed the morphology of nZVI but barely influenced the removal efficiency. Competing ions showed diverse influence between Sb(III) and Sb(V). The overall results indicated that nZVI was an efficient and suitable material for the removal of antimony.

Arsenic(III), but not antimony(III), induces DNA-protein crosslinks.

Abstract: Antimony compounds are supposed to resemble to arsenicals in some toxicological features. Comparative investigations with antimony and arsenic were performed to collect data on the genotoxicity of antimony, on which the knowledge is scarce. In comparison to trivalent arsenic, trivalent antimony proved to be five times less cytotoxic in the neutral red assay and one order of magnitude less genotoxic in the cytokinesis-block micronucleus test using V79 Chinese hamster cells. The data obtained in the comet assay showed that the As(III)-mediated generation of DNA-protein crosslinks and DNA strand lesions seem to be two independent processes. In contrast, Sb(III) induced DNA strand lesions but not DNA-protein crosslinks. Further studies will have to investigate whether the genotoxicity of Sb(III) is mediated by an inhibition of DNA repair as it seems to be the case for As(III).