A Stable Dimer of SiS2 Arranged between Two Carbene Molecules

• Published in: Chemistry : a European journal 2015-09, Vol.21 (36), p.12572-12576
• Main Authors: Mohapatra, Chandrajeet, Mondal, Kartik Chandra, Samuel, Prinson P., Keil, Helena, Niepötter, Benedikt, Herbst-Irmer, Regine, Stalke, Dietmar, Dutta, Sayan, Koley, Debasis, Roesky, Herbert W.
• Format: Article
• Language: English
• Subjects: Chemistry; density functional calculations; main group chemistry; silicon; silylene; sulfur activation
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201502092

The Me‐cAAC:‐stabilized dimer of silicon disulfide (SiS2) has been isolated in the molecular form as (Me‐cAAC:)2Si2S4 (2) at room temperature [Me‐cAAC:=cyclic alkyl(amino) carbene]. Compound 2 has been synthesized from the reaction of (Me‐cAAC:)2Si2 with elemental sulfur in a 1:4 molar ratio under oxidative addition. This is the smallest molecular unit of silicon disulfide characterized by X‐ray crystallography, electron ionization mass spectrometry, and NMR spectroscopy. Structures with three sulfur atoms arranged around a silicon atom are known; however, 2 is the first structurally characterized silicon–sulfur compound containing one terminal and two bridging sulfur atoms at each silicon atom. Compound 2 shows no decomposition after storing for three months in an inert atmosphere at ambient temperature. The bonding of 2 has been further studied by theoretical calculations. cAAC‐Stabilized Si2S4: A molecular dimer of SiS2 is stabilized by two cyclic alkyl(amino) carbenes (cAACs) at ambient temperature. (Me‐cAAC)2Si2S4 was synthesized by activation of elemental sulfur by a diatomic silicon(0) precursor possessing a SiSi bond. This dimer features a silicon–sulfur compound containing terminal and bridging sulfur atoms at the same silicon atom. (Me‐cAAC)2Si2S4 is highly stable in air.