Two-electron versus one-electron reduction of chalcogens by uranium(III): synthesis of a terminal U(V) persulfide complex
The reaction of the tripodal tris-amido U(iii) complex [U(SiMe 2NPh)3-tacn] (tacn = 1,4,7-triazacyclononane), 1, with 0.0625 and 0.25 equiv. of elemental sulfur affords the sulfide-bridged U(iv) complex [U((SiMe2NPh)3-tacn)2(μ-S)], 2, and the terminal persulfide U(v) complex [U(SiMe2NPh) 3-tacn(η2-S2)], 4, respectively, in good yield. Two different electronic structures, U(v) persulfide and U(iv) supersulfide, were computed for complex 4 at the DFT level. The results show that complex 4 is best described as a U(v) persulfide species with a significant sulfur contribution. X-ray, magnetism and electrochemistry data support this description. Complex 4 is the first example of a terminal U(v) persulfide and of a two-electron reduction of S8 by a U(iii) complex. Complex 4 behaves as a S-atom transfer agent when reacted with PPh3, affording the persulfide-bridged diuranium(iv) complex [U((SiMe2NPh) 3-tacn)2(μ-η2:η2-S 2)], 5, and SPPh3. © 2014 The Royal Society of Chemistry.
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Camp, C., Antunes, M. A., Garcia, G., Ciofini, I., Santos, I. C., Pecaut, J., Almeida, M., Marcalo, J., & Mazzanti, M. (2014). Two-electron versus one-electron reduction of chalcogens by uranium(III): synthesis of a terminal U(V) persulfide complex. Chemical Science, 5(2), 841–846. https://doi.org/10.1039/c3sc52742e
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WOS:000328954200052
2014
5
2
841
846
REVIEWED
OTHER