Multinuclear ((1)H, (77)Se, and (199)Hg) NMR spectroscopy demonstrates that 1-methyl-1,3-dihydro-2H-benzimidazole-2-selone, H(sebenzim(Me)), a structural analogue of the selenoamino acid, selenoneine, binds rapidly and reversibly to the mercury centers of HgX2 (X = Cl, Br, I), while X-ray diffraction studies provide evidence for the existence of adducts of composition [H(sebenzim(Me))]xHgX2 (X = Cl, x = 2, 3, 4; X = I, x = 2) in the solid state. H(sebenzim(Me)) also reacts with methylmercury halides, but the reaction is accompanied by elimination of methane resulting from protolytic cleavage of the Hg-C bond, an observation that is of relevance to the report that selenoneine demethylates CysHgMe, thereby providing a mechanism for mercury detoxification. Interestingly, the structures of [H(sebenzim(Me))]xHgX2 exhibit a variety of different hydrogen bonding patterns resulting from the ability of the N-H groups to form hydrogen bonds with chlorine, iodine, and selenium.
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http://dx.doi.org/10.1021/jacs.5b00840 | DOI Listing |
Acc Chem Res
December 2023
Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo, Norway.
ConspectusThe early years of gold catalysis were dominated by Au(I) complexes and inorganic Au(III) salts. Thanks to the development of chelating ligands, more sophisticated Au(III) complexes can now be easily prepared and handled. The choice of the ancillary ligand has great consequences for the synthesis, properties, and reactivity of the Au(III) complex in question.
View Article and Find Full Text PDFChem Sci
December 2019
Leibniz Institut für Katalyse e. V. , Albert-Einstein-Straße 29a , Rostock , 18059 , Germany . Email:
A series of molybdenum pincer complexes has been shown for the first time to be active in the catalytic hydrogenation of amides. Among the tested catalysts, proved to be particularly well suited for the selective C-N hydrogenolysis of -methylated formanilides. Notably, high chemoselectivity was observed in the presence of certain reducible groups including even other amides.
View Article and Find Full Text PDFInorg Chem
February 2018
Department of Chemistry, Columbia University, New York, New York 10027, United States.
A series of tris(oxoimidazolyl)hydroborato ligands, which serve as LX [O] donors, have been employed to obtain organometallic zirconium compounds in an uncommon oxygen-rich coordination environment. For example, Cp[To]ZrCl has been synthesized via the reaction of [To]Na with CpZrCl and bears a structural resemblance to the bent metallocene dichloride derivative CpZrCl. In addition, the half-sandwich counterparts [To]ZrCl and [To]ZrCl have been obtained by metathesis of ZrCl with [To]Na and [To]Na, respectively.
View Article and Find Full Text PDFChem Commun (Camb)
February 2016
Department of Chemistry, Columbia University, New York, NY 10027, USA.
The first terminal zinc hydride complex that features a sulfur-rich coordination environment, namely the tris(2-mercapto-1-tert-butylimidazolyl)hydroborato compound, [Tm(Bu(t))]ZnH, has been synthesized via the reaction of [Tm(Bu(t))]ZnOPh with PhSiH3. The Zn-H bond of [Tm(Bu(t))]ZnH is subject to insertion of CO2 and facile protolytic cleavage, of which the latter provides access to heterobimetallic [Tm(Bu(t))]ZnMo(CO)3Cp.
View Article and Find Full Text PDFPolyhedron
January 2016
Department of Chemistry, Columbia University, New York New York 10027, USA.
The phenylselenolate mercury alkyl compounds, PhSeHgMe and PhSeHgEt, have been structurally characterized by X-ray diffraction, thereby demonstrating that both compounds are monomeric with approximately linear coordination geometries; the mercury centers do, nevertheless, exhibit secondary Hg•••Se intermolecular interactions that serve to increase the coordination number in the solid state. The ethyl derivative, PhSeHgEt, undergoes facile protolytic cleavage of the Hg-C bond to release ethane at room temperature, whereas PhSeHgMe exhibits little reactivity under similar conditions. Interestingly, the cleavage of the Hg-C bond of PhSeHgEt is also more facile than that of the thiolate analogue, PhSHgEt, which demonstrates that coordination by selenium promotes protolytic cleavage of the mercury-carbon bond.
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