Azido derivatives of germanium(II) and tin(II): Syntheses and characterization of [(Mes)(2)DAP]GeN3, [(Mes)(2)DAP]SnN3, and the corresponding chloro analogues featuring heterocyclic six-pi-electron ring systems (where [(Mes)(2)DAP] = {N(Mes)C(Me)}(2)CH)

Chloro and azido germanium(II) and tin(II) 1,5-diazapentadienyl complexes h ave been investigated. The treatment of GeCl2. (1,4-dioxane) or SnCl2 with [(Mes)(2)DAP]Li in a 1:1 molar ratio gave the corresponding germanium(II) o r tin(II) chloro complexes [(Mes)(2)DAP]MCl (where [(Mes)(2)DAP] =2,4-dimet hyl-N,N'-bis(2,4,6-trimethylphenyl)1,5-diazapentadienyl; M = Ge or Sn). [(M es)(2)DAP]GeCl and [(Mes)(2)DAP]SnCl are monomeric in the solid state. The C3N2M rings adopt a flattened boat conformation. The metathesis reaction be tween [(Mes)(2)DAP]MCl and sodium azide affords the azido compounds [(Mes)( 2)DAP]MN3 in excellent yield. X-ray analysis revealed that [(Mes)(2)DAP]GeN 3 features an essentially linear azide moiety and a nearly planar heterocyc lic C3N2Ge ring system. The azide group occupies a site above the C3N2Ge ri ng. The solid-state structure of the tin azide [(Mes)(2)DAP]-SnN3 shows wea k intermolecular Sn . . .N contacts. It features a linear azide moiety and a planar heterocyclic C3N2Sn ring system. Both azides have long (M)N-N(N) b onds and short (MN)N-N bonds. IR spectra of [(Mes)(2)DAP]GeN3 and [(Mes)(2) DAP]SnN3 display nu (asym)(N-3) bands at 2062 and 2060 cm(-1), respectively . N-14 NMR spectroscopic data show three well-separated signals for the nit rogen atoms of the azide moieties. Structural and spectroscopic data sugges t the presence of very similar azide groups in the Ge(II) and Sn(II) adduct s. The dominant canonical form of the metal-azide moiety is M-N-N equivalen t toN.