Azido derivatives of germanium(II) and tin(II):syntheses and characterization of [(Mes)_2DAP]GeN_3,[(Mes)_2DAP]SnN_3,and the corresponding chloro analogues featuring heterocyclic six-#pi#-electron ring systems (where [(Mes)_2DAP]={N(Mes)C(Me)}_2CH

摘要

Chioro and azido germanium(ll) and tin(lI) I ,5-diazapentadienyl complexes have been investigated. The treatmert of GeCl2( I .4-dioxane) or SnCl_2 with [(Mes)_2DAP]Li in a 1:1 molar ratio gave the corresponding germanium(I.b or tin(II) chloro complexes f(Mes)_2DAP]MCl (where [(Mes)2DAPI 2,4-dimethyl-N,N’-bis(2,4,6-trimethylphenvl 1,5-diazapentadienyl; M Ge or Sn). [(Mes)_2DAPJGeCI and ((Mes)_2DAPISnCI are monomeric in the solid state The C_3N_2M rings adopt a flattened boat conformation. The metathesis reaction between VMes)_2DAP]MCl and sodium azide affords the azido compounds [(Mes)_2DAP]MN_3 in excellent yield. X-ray analysis revealed that [(Mes)_2DAP]GeN_3 features an essentially linear azide moiety and a nearly planar heterocyclic C_3N_2Ge ring system. The azide group occupies a site above the C_3N_2Ge ring. The solid-state structure of the tin azide [(Mes)2DAPI-SnN3 shows weak intermolecular Sn” ‘N contacts. It features a linear azide moiety and a planar heterocyclic C3N2Sn ring systam. Both azides have long (M)N—N(N) bonds and short (MN)N—N bonds. IR spectra o [(Mes)2DAP]GeN3 and [(Mes)2DAP]SnN3 display V~ym(N3) bands at 2062 and 2060 cm’, respectively. 14N NMR spectroscopic data show three well-separated signals for the nitrogen atoms of the azide moieties. Structural and spectroscopic data suggest the presence of very similar azide groups in the Ge(II) and Sn(II) adducts. The dominant canonical form of the metal—azide moiety is M—N-Nident toN.