- Redox reaction between main-group elements (Te, Sn, Bi) and N-Heterocyclic-carbene-derived selenium halides: A facile method for the preparation of monomeric halides
-
The synthesis and characterization of substituted benzimidazolin-2-selones (4c-4d) and -tellone (4i) are reported. Upon reaction with halogens (I 2, Br2, and Cl2), these selones and tellone yield dihaloselones/tellone (5c-5i). The reaction of dihaloselones with elemental tellurium/tin/bismuth leads to the formation of selone-coordinated monomeric tellurium tetrahalides, tellurium dibromide (8), tin tetrahalides, and bismuth triiodide adducts (7a-7g), respectively. The structures of the tellurium tetrahalide (7a, 7d, and 7g), tellurium dibromide (8), tin tetrahalide, and bismuth triiodide adducts have been established by single-crystal X-ray analysis. The bismuth triiodide adduct is the first neutral tetrameric structure with selones. The bismuth adduct has been used as a single-source precursor for the synthesis of bismuth selenide (Bi 2Se3) nanoparticles, which were characterized by powder XRD patterns. The TEM images show the hexagonal shape of the nanoparticles. The reaction of dihaloselones with elemental tellurium leads to the formation of selone- coordinated monomeric tellurium tetrahalides and tellurium dibromide adducts. A plausible mechanism for the formation of tellurium halide adducts is proposed. Tellurium halide adducts are probably an intermediate in the formation of cationic diselenides. Copyright
- Manjare, Sudesh T.,Yadav, Sangeeta,Singh, Harkesh B.,Butcher, Ray J.
-
p. 5344 - 5357
(2013/11/06)
-
- Facile synthesis of benzimidazolin-2-chalcogenones: Nature of the carbon-chalcogen bond
-
A new method using chalcogen nucleophiles E2-/E2 2- (E = S, Se, Te) for the convenient and high yield synthesis of benzimidazolin-2-chalcogenones has been developed. The reaction of strong nucleophiles E2-/E22- with various benzimidazolium salts under mild conditions afforded benzimidazolin-2- chalcogenones (10a-10g) in better yield compared to the other methods involving E0 powder. Benzimidazolin-2-tellurones were found to be unstable when pyridyl/phenyl groups were bonded to one of the nitrogens of the benzimidazolium salts and the reaction led to the isolation of the corresponding diamines (12a and 12b). The selenones/tellurones could be easily oxidized to the corresponding dihaloderivatives (16a-16e) by the reaction of the chalcogenones with bromine/iodine. The nature of the carbon-chalcogen double bond has been investigated with the help of single crystal X-ray, NMR spectroscopy and Density Functional Theory (DFT) calculations.
- Manjare, Sudesh T.,Sharma, Sagar,Singh, Harkesh B.,Butcher, Ray J.
-
-