Reactivity of the disilyne RSi[triple bond]SiR (R = Si(i)Pr[CH(SiMe3)2]2) toward silylcyanide: two pathways to form the bis-adduct [RSiSiR(CNSiMe3)2] with some silaketenimine character and a 1,4-diaza-2,3-disilabenzene analogue.
The reaction of 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyltetrasila-2-yne 1 with trimethylsilylcyanide produced the bis-adduct [RSiSiR(CNSiMe(3))(2)] (R = Si(i)Pr[CH(SiMe(3))(2)](2)) 2 and a 1,4-diaza-2,3-disilabenzene analogue 3, which were characterized by spectroscopic data as well as X-ray crystallography (for 2). These two products were produced by different isomers of trimethylsilylcyanide reacting with the disilyne; bis-adduct 2 was formed from the isocyanide form, and compound 3 was produced from the cyanide form followed by cyclization. The bis-adduct 2 is shown on the basis of X-ray crystallography structural data and theoretical studies to exhibit some bis(silaketenimine) character with zwitterionic contributions. The dl-form of dicyano compound 4 was preferentially produced by the reaction of 2 with methanol.
Takeuchi
Katsuhiko
K
Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
Ichinohe
Masaaki
M
Sekiguchi
Akira
A