title: Optical spectra, electronic structure and aromaticity of benzannulated N-heterocyclic carbene and its analogues of the type C6H4(NR)2E: (E = Si, Ge, Sn, Pb).
abstract: A series of benzannulated N-heterocyclic compounds containing divalent 14 group atoms, C6H4(NR)2EII, E = C, Si, Ge, Sn, Pb, have been studied by various experimental (vibrational and UV-vis spectroscopy) and theoretical (NICS, ISE, ACID) techniques. The methods used confirm 10 π-electron delocalization (aromaticity) in these heterocycles, however, the aromaticity sequences estimated by the criteria based on different physical properties do not coincide.
authors.affiliation: Scientific and Technical Center on Raman Spectroscopy, A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova str., Moscow 119991, Russia. buklei@ineos.ac.ru.
authors.forename: Rinat R
authors.initials: RR
authors.lastname: Aysin
authors.forename: Sergey S
authors.initials: SS
authors.lastname: Bukalov
authors.forename: Larissa A
authors.initials: LA
authors.lastname: Leites
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Zabula