On the way to a disilyne RSi SiR, part 2. Compounds of silicon and homologues, part 153. Synthesis, structure and dehalogenation of the disilene RClSi=SiClR [R=(tBu(3)Si)(2)MeSi]

• Published in: European journal of inorganic chemistry no. 5; pp. 1066 - 1070
• Main Authors: Wiberg, N, Niedermayer, W, Fischer, G, Noth, H, Suter, M
• Format: Journal Article
• Language: English
• Published: MALDEN Wiley 01.05.2002
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Physical Sciences; Science & Technology; disilyne; R-ASTERISK; SITBU; silylene; XSI; disilene; ASTERISK-XSI=SIXR-ASTERISK; HAL; silicon; PH; ME; X-ray structure analysis; BOND
• ISSN: 1434-1948

The reaction of R*(2)MeSi-SiX(2)X' (X/X' = CI/Br, Br/Cl) with NaR* (R* = supersilyl SitBu(3)) leads, probably via the silylenes R*(2)MeSi-SiX, to the trans-configurated disilene (R*(2)MeSi)ClSi=SiCl(SiMeR*(2)), which could be isolated as orange-red crystals. According to an X-ray structure analysis, the central SiClSi=SiClSi framework of the disilene - the formation mechanisms of which are discussed - is planar, The Si=Si double bond is as short as 2.163(4) Angstrom and shows a band in the Raman spectrum at 589 cm(-1). Due to its insolubility in organic solvents, no NMR spectra of the disilene in solution were obtained. The spatially overcrowded disilene is stable towards H(2)O, MeOH, HF, and NaR*, It melts at 228 degreesC with decomposition. Reduction of the disilene occurs with LiC(10)H(8) in THF with formation of a reaction mixture containing a chlorine-free product that gives a low field (29)Si NMR signal at 6 = 91,5 (the region for unsaturated Si atoms). It transforms in solution with traces of oxygen into a substance which, according to mass spectrometry (chemical ionization), shows a mass for the disilyne R*(2)MeSi-SidropSi-SiMeR*(2) Plus two oxygen atoms. (C) Wiley-VCH Verlag GmbH.