Diradicaloid or Zwitterionic Character: The Non-Tetrahedral Unsaturated Compound [Si-4{N(SiMe3) Dipp}(4)] with a Butterfly-type Si-4 Substructure

Autor(es)

Keuter, Jan ; Schwedtmann, Kevin ; Hepp, Alexander ; Bergander, Klaus ; Janka, Oliver ; Doerenkamp, Carsten ; Eckert, Hellmut ; Mueck-Lichtenfeld, Christian ; Lips, Felicitas

• Tipo de documento: Artigo Científico
• Fonte: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION; v. 56, n. 44, p. 6-pg., 2017-10-23.

Resumo

The reduction of the tribromoamidosilane {N(SiMe3) Dipp} SiBr3 (Dipp= 2,6-iPr(2)C(6)H(3)) with potassium graphite or magnesium resulted in the formation of [Si-4{N-(SiMe3) Dipp}(4)] (1), a bicyclo[1.1.0] tetrasilatetraamide. The Si-4 motif in 1 does not adopt a tetrahedral substructure and exhibits two three-coordinate and two four-coordinate silicon atoms. The electronic situation on the three-coordinate silicon atoms is rationalized with positive and negative polarization based on EPR analysis, magnetization measurements, and DFT calculations as well as 29Si CP MAS NMR and multinuclear NMR spectroscopy in solution. Reactivity studies with 1 and radical scavengers confirmed the partial charge separation. Compound 1 reacts with sulfur to give a novel type of silicon sulfur cage compound substituted with an amido ligand, [Si-4{N-(SiMe3) Dipp}(4)](2). (AU)

• Processo FAPESP: 17/06649-0 - Novos materiais óticos baseados em vidros e cerâmicas oxifluoretos dopados com terras-raras: estudos estruturais por ressonância paramagnética eletrônica.
• Beneficiário: Carsten Doerenkamp
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado