Darstellung, 11B-NMR-, Schwingungsspektren und Kristallstruktur von [(C5H5N)2CH2][1-(O2N)B10H9]

Preparation, ¹¹B NMR, Vibrational Spectra, and Crystal Structure of [(C₅H₅N)₂CH₂][1-(O₂N)B₁₀H₉] By reaction of [B₁₀H₁₀]^2? in aqueous acetonitrile with a saturated solution of NO₂ in dichloromethane [1-(O₂N) · B₁₀H₉]^2? and [B₁₀H₉(NO)B₁₀H₉]^3? are formed which can be separated by ion exchange chromatography on diethylaminoethyl(DEAE) cellulose from the starting compound. The X-ray structure determination of [(C₅H₅N)₂CH₂][1-(O₂N)B₁₀H₉] (triclinic, space group P1 , a = 7.1530(9), b = 8.3753(8), c = 15.198(2) Å, α = 96.00(1), β = 95.48(1), γ = 95.60(1)°, Z = 2) reveals the coordination of the NO₂ group via N with a B1? N distance of 1.535(5) Å and an O2? N? O1 angle of 119.3(3)°. The ¹¹B NMR spectrum exhibits the characteristic feature (1 : 1 : 4 : 4) of an apical monosubstituted B₁₀ cluster with a strong downfield shift of the ipso-B atom at +13.4 ppm. The IR and Raman spectra show strong NO stretching vibrations at 1381 und 1420 cm^?1.