Azido derivatives of low-valent group 14 elements: Synthesis, characterization, and electronic structure of [(n-Pr)(2)ATI]GeN3 and [(n-Pr)(2)ATI]SnN3featuring heterobicyclic 10-pi-electron ring systems
Ae. Ayers et al., Azido derivatives of low-valent group 14 elements: Synthesis, characterization, and electronic structure of [(n-Pr)(2)ATI]GeN3 and [(n-Pr)(2)ATI]SnN3featuring heterobicyclic 10-pi-electron ring systems, INORG CHEM, 39(18), 2000, pp. 4147-4151
Treatment of THF solutions of [(n-Pr)(2)ATI]MCl (where [(n-Pr)(2)ATI](-) =
N-(n-propyl)-2-(n-propylamino)-troponiminate; M = Ge and Sn) with sodium az
ide affords the compounds [(n-Pr)(2)ATI]MN3 in excellent yield. X-ray analy
ses revealed that these Ge(II) and Sn(II) compounds feature linear azide mo
ieties and planar heterobicyclic C7N2M ring systems. Germanium and tin atom
s adopt a pyramidal geometry. IR spectra of [(n-Pr)(2)ATI]GeN3 and [(n-Pr)(
2)ATI]SnN3 display a upsilon(asym)(N-3) band at 2048 and 2039 cm(-1), respe
ctively. DFT. calculations on the corresponding methyl-substituted species
demonstrate that the geometrical and electronic structure of these two spec
ies are very similar, and the dominant canonical form of the metal-azide mo
iety is M-N-N=N. The tin system is, as expected, slightly more ionic. A com
parative CASSCF/DFT study on the model system H-Sn-N-3 illustrates that the
DFT approach is viable for the calculation of the structures of these spec
ies.