title: Molecular Structures of N,N'-Dimethylbenzimidazoline-2-germylene and -stannylene in Solution and in Solid State by Means of Optical (Raman and UV-vis) Spectroscopy and Quantum Chemistry Methods.
abstract: X-ray data obtained for germylene 1 evidence its monomeric structure, unlike that of stannylene 2, which had been shown previously to form a coordination dimer. Raman spectra of solid and liquid 1 are identical, whereas the Raman spectra of solid 2 and its solution 2a differ significantly. The spectrum of 2 is complicated and contains the lines corresponding to N → Sn coordination bonds forming a dimer. The spectrum of 2a is simpler and close to that of monomeric 1, thus pointing to the rupture of the dimer in solution. The UV-vis spectrum of solid 2 exhibits a band corresponding to a transition involving the N → Sn coordination bonds. Quantum theory of atoms in molecules data estimate the energy of this bond as ∼19 kcal/mol. The aromaticity of 1 and 2 with their 10 π-electron systems including divalent Ge or Sn atoms is confirmed by negative nucleus-independent chemical shift values.
authors.affiliation: Scientific and Technical Center on Raman Spectroscopy, A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilova street, Moscow 119991, Russia.
authors.forename: R R
authors.initials: RR
authors.lastname: Aysin
authors.affiliation: Scientific and Technical Center on Raman Spectroscopy, A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilova street, Moscow 119991, Russia.
authors.forename: L A
authors.initials: LA
authors.lastname: Leites
authors.affiliation: Scientific and Technical Center on Raman Spectroscopy, A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilova street, Moscow 119991, Russia.
authors.forename: S S
authors.initials: SS
authors.lastname: Bukalov
authors.affiliation: Organosilicon Research Center, University of Wisconsin , Madison, Wisconsin 53706, United States.
authors.forename: A V
authors.initials: AV
authors.lastname: Zabula
authors.affiliation: Organosilicon Research Center, University of Wisconsin , Madison, Wisconsin 53706, United States.
authors.forename: R
authors.initials: R
authors.lastname: West