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Updated: Jul 15, 2026

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
From thiocarbonyl dihalides to their carbocation derivatives - synthesis, structure and bonding
Hennes Günther1, Sven Ringelband1, Franka Rischer1
1Department of Chemistry, Philipps University of Marburg, Hans-Meerwein-Str. 4 D-35043, Marburg, Germany. frank.tambornino@chemie.uni-marburg.de.
Abstract:
The dimer of thiocarbonyl dibromide was prepared via bromination of CSCl2 followed by sunlight irradiation or by solvent-free bromination of C2S2Cl4. Thermal induced cycloreversion at 155 °C affords light sensitive red liquid CSBr2, as confirmed by 13C NMR spectroscopy (135.4 ppm). In situ single-crystal X-ray diffraction reveals disorder of Br/S atom positions, resulting in hexagonal spacegroup P63/m. Halide abstraction of C2S2Cl4 and C2S2Br4, yields glovebox-stable carbocations [C2S2X3]+, accessible via salt elimination or Lewis acid base reaction. Comparison with the respective neutral dimers shows bond contraction and planarization, while computational analysis of [C2S2X3]+ and C2S2X4 (X = F-I) reveals halogen dependend σ bond contribution and atomic charges.
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