title: Azido derivatives of low-valent group 14 elements: synthesis, characterization, and electronic structure of [(n-Pr)2ATI]GeN3 and [(n-Pr)2ATI]SnN3 featuring heterobicyclic 10-pi-electron ring systems.
abstract: Treatment of THF solutions of [(n-Pr)2ATI]MCl (where [(n-Pr)2ATI]- = N-(n-propyl)-2-(n-propylamino)troponiminate; M = Ge and Sn) with sodium azide affords the compounds [(n-Pr)2ATI]MN3 in excellent yield. X-ray analyses revealed that these Ge(II) and Sn(II) compounds feature linear azide moieties and planar heterobicyclic C7N2M ring systems. Germanium and tin atoms adopt a pyramidal geometry. IR spectra of [(n-Pr)2ATI]GeN3 and [(n-Pr)2ATI]SnN3 display a nu asym(N3) band at 2048 and 2039 cm-1, respectively. DFT calculations on the corresponding methyl-substituted species demonstrate that the geometrical and electronic structure of these two species are very similar, and the dominant canonical form of the metal-azide moiety is M-N-N identical to N. The tin system is, as expected, slightly more ionic. A comparative CASSCF/DFT study on the model system H-Sn-N3 illustrates that the DFT approach is viable for the calculation of the structures of these species.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019-0065, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Ayers
authors.forename: D S
authors.initials: DS
authors.lastname: Marynick
authors.forename: H V
authors.initials: HV
authors.lastname: Dias