Monomeric bivalent group 4B metal dialkylamides M[NCMe2(CH2)3CMe2]2(M = Ge or Sn), and the structure of a gaseous disilylamide, Sn[N(SiMe3)2]2, by gas electron diffraction

Reaction of Li[[graphic omitted]Me2](LiNR2) in n-C5H12 at 20°C with GeCl2·dioxan or SnCl2 affords the corresponding coloured crystalline diamagnetic metal(II) dialkylamide, M(NR2)2, which is monomeric (cryoscopy in C6H12), has a low first ionisation potential (6·90 eV for M = Ge, 6·80 eV for M = Sn), and furnishes the 2,2,6,6-tetramethylpiperidyl radical :NR2 upon photolysis; electron diffraction analysis of gaseous Sn[N(SiMe3)2]2 shows only the monomer at ca. 100°C and 10–2 atm, which has C2v symmetry, ∠NSnN = 96·0°, and Sn–N (av.)= 2·09 Å.